## Abstract

How do great powers decide whether to provide arms to or form alliances with client states? This “patron's dilemma” revolves around a decision about how to best provide security to clients without becoming entrapped in unwanted conflicts. Strong commitments worsen the risk of entrapment, whereas weak commitments intensify fears of abandonment. This traditional alliance dilemma can be addressed through the provision of arms and alliances. Great power patrons primarily make such decisions on the basis of two factors: first, the extent to which the patron believes it and its client have common security interests; and second, whether the patron believes that its client has sufficient military capabilities to deter its main adversary without the patron's assistance. Patrons assess the degree of shared threat and the local balances of capabilities in determining whether to support their clients with arms, alliances, or both. As demonstrated in the U.S. provision of security goods to Taiwan and Israel during the Cold War, this strategic logic explains how great powers manage the patron's dilemma.

## Introduction

Under what conditions do great power patrons offer client states arms, alliances, or both? Why do great powers sometimes provide arms to their clients and why do they sometimes form alliances with their clients?

These questions are important in international politics because great powers face a “patron's dilemma.” Great powers must adopt policies to provide security to their allies without becoming entrapped in an unwanted conflict. Strong commitments, such as treaty alliances, worsen the risk of entrapment—that is, the patron's fear of being dragged into an undesirable war. Weak commitments, such as verbal assurances, intensify a client's fears of abandonment—in other words, the client's fear of receiving inadequate support should a crisis develop. Such is the traditional alliance dilemma that has been analyzed by Glenn Snyder and other scholars.1

Grasping the patron's dilemma is central to understanding not only U.S. security commitments but also many related patterns of interstate behavior. For example, efforts to secure an Iranian nuclear deal have produced calls for stronger defense ties between the United States and Israel, Saudi Arabia, and the United Arab Emirates, among others. Such ties could include formal treaty alliances or the sale of additional arms. Some analysts warn that insufficient assurances could trigger nuclear proliferation or even regional war. Elsewhere in the world, China's recent assertiveness has made U.S. allies, such as Japan and the Philippines, and partners, such as Vietnam and Taiwan, anxious. This alliance anxiety has forced the United States to reconsider its provision of arms and alliances. Similar issues are at play with Ukraine. Actual and potential Russian aggression toward Eastern Europe has fueled debate about whether existing U.S. security guarantees are sufficient and whether Ukraine should receive lethal U.S. arms. In all these regions, we expect the patron's dilemma to remain intense. This article elucidates the choices and constraints facing decisionmakers managing this dilemma.

The decisions of great powers to transfer arms or form alliances often present intriguing empirical puzzles. In 2015, the United States supported thirty-two treaty allies and allocated billions in security assistance worldwide. Surprisingly, U.S. treaty allies received only 2 percent of all U.S. foreign military financing, whereas five non-allied countries received more than 90 percent. Among this group of five non-allied U.S. partners, Israel received $3.1 billion (55 percent of U.S. foreign military financing), Egypt$1.3 billion (23 percent), Jordan $300 million (5 percent), Pakistan$280 million (5 percent), and Iraq $250 million (5 percent).2 This variation is even more intriguing when considered historically. During the Cold War, the United States provided weapons and alliances to many states, including Pakistan and Taiwan, but transferred arms to Israel without a formal defense pact. Yet Pakistan and Taiwan eventually lost their alliances despite seeing U.S. arms transfers continue, if not increase. Why did the United States modulate its arms and alliances provision during the Cold War? And why would it today decline to offer some states defense pacts but give them more military financing than it does to its treaty allies? A patron's choice to provide arms, alliances, or both, raises academic questions because extending alliances and transferring arms produce many similar benefits. Both policies are useful for deterring adversaries and reassuring clients while exerting some influence over them. Alliances strengthen deterrence and defense by aggregating capabilities and enhancing combined operations and planning. Arms transfers deter and defend by altering the local military balance. Like alliances, arms transfers can signal a patron's commitment to maintain its client's security. Still, the conditions under which great power patrons transfer arms and extend defense pacts have not been thoroughly examined. In the relatively small literature on this topic, prominent scholars have argued that U.S. military assistance—arms or alliances—to clients is driven by nonstrategic calculations, such as domestic political factors or commercial motivations.3 In this article, we offer a unified strategic logic that explains how patrons calibrate the provision of arms and alliances. We argue that patrons make such decisions primarily on the basis of two factors: first, the extent to which the patron believes that it and its client have common security interests; and second, whether the patron believes that its client has military capabilities sufficient to deter its main adversary and prevail should deterrence fail. These two variables interact to shape the bundle of security commitments—arms and alliances—that the patron offers to its client. Our analysis reveals when patrons use these security goods as substitutes and complements.4 We shed light on how patrons manage the alliance dilemma by using arms transfers to affect the behavior of their clients. We show that arms and alliances can help to reassure clients and mitigate their fears of abandonment by complementing existing alliances while minimizing entrapment risks. Simply put, the patron's dilemma revolves around how best to use arms transfers to address the alliance dilemma. Our theoretical framework builds on previous work regarding how great powers calibrate the provision of arms, alliances, or both, to serve their interests while managing their clients' behavior.5 We extend this approach by demonstrating how security commitments change over time. In so doing, we show how decisionmakers concerned with entrapment take measures to mitigate such concerns. Our analysis thus challenges the notion that clients can entrap patrons that are providing arms rather than alliances. Using primary documents, we assess how decisionmakers regard the risks and opportunities that come with providing arms and alliances. Our empirical findings provide weak evidence for claims that domestic politics and commercial interests explain patrons' decisions to transfer arms or form alliances. Rather, our evidence strongly suggests that even in controversial cases where such alternative explanations are plausible, strategic variables are more salient to U.S. decisionmakers. We do not dismiss the importance of these alternative explanations, but instead show how U.S. decisionmakers focused primarily on the commonality of security interests and the local military balance in determining which bundles of military assistance to give to client states. More broadly, our argument contributes to a growing literature on interstate signaling by examining the conditions under which arms transfers and alliances serve as alternative or complementary costly signals of support to a client. Of course, patrons can use other goods (e.g., forward deployments and joint military exercises) to further their clients' security interests. We focus on arms transfers and alliances, however, because both can be described as distinct signals of patron support with separate cost structures. Alliances reflect ex post reputational costs that would be imposed on the patron if it did not defend the ally in a crisis, whereas arms transfers hinge on the logic of ex ante sunk costs, referring to the financial costs paid by the patron before the crisis. Together, our theory and empirical analysis demonstrate how variation in these cost structures explains utilization of these policies, and how leaders perceive the relative utility of these tools.6 We proceed as follows. The first section reviews existing conceptualizations of alliances and arms. The second section describes our theory. The third section discusses our research design and reviews the two main alternative arguments: domestic political and commercial explanations. The fourth and fifth sections examine U.S. efforts to provide arms and alliances to Taiwan and Israel, respectively. The conclusion summarizes our argument and outlines policy implications drawn from our analysis. ## Alliances and Arms: A Theoretical Overview In this section, we discuss the factors that great power patrons consider in determining whether to support a potential client through an alliance commitment or through arms transfers. We explain the extent to which both of these security goods serve similar functions, and how differences between them shape when each is selected. ### ALLIANCE COMMITMENTS Alliances are written pledges between two or more states that are intended to formalize some form of security cooperation.7 In this article, we set aside offensive alliances and nonaggression pacts to focus on defensive alliances (or defense pacts), in which members pledge to come to each other's aid in the event that one member experiences external aggression. Alliances deter adversaries by aggregating and, through joint military exercises and operational planning, enhancing capabilities. Alliances are ex post commitments that bolster the credibility of a state's promise to intervene on behalf of an ally by putting the state's reputation at stake.8 Reneging on commitments is costly because it affects a state's ability to negotiate future alliance treaties.9 States face a dilemma in deciding the strength of their alliance commitments. Too weak a commitment could embolden an adversary and inspire abandonment fears in an ally because the patron might decline to assist it during a crisis. Too strong a commitment, such as one that is explicit, broad, and binding, could embolden a client to pursue risky or aggressive policies. This latter possibility fuels a patron's fear of being militarily entrapped by a risktaking ally that could drag the patron into an unwanted war.10 Of course, all alliance commitments imply some risk of entanglement, which Tongfi Kim defines as “the process whereby a state is compelled to aid an ally in a costly and unprofitable enterprise because of the alliance.11 Institutional arrangements sometimes enable the patron to mitigate this entanglement risk.12 Ambiguous commitments can make both clients and adversaries cautious, because they are unsure which obligations and conditions will trigger an alliance response. Defense pacts are unconditional if they leave unspecified the terms under which the patron will aid its client. Defense pacts are conditional if they attach public or private terms or contain ambiguous language designed to reduce an ally's moral hazard—that is, its willingness to take risky actions knowing that its patron will come to its defense.13 These arrangements are imperfect, however. For example, determining whether an attack was provoked can be difficult, thereby calling into question the applicability of a conditional defense pact. Accordingly, conditional alliances can undercut deterrence if a potential adversary believes that it can circumvent a great power's alliance commitments.14 ### ARMS TRANSFERS In an arms transfer, a state gives another state weapons to augment its military capabilities. Like alliances, arms transfers deter and defend by shifting the local balance of power in the recipient's favor. Yet, they differ from alliances in three ways. First, a patron can decide to transfer arms quickly and sometimes without involving domestic legislatures, whereas alliances often take time to negotiate and ratify. Second, a patron can modulate the magnitude and type of military assistance it provides over time. Alliance commitments are generally more static and difficult to calibrate. Third, although alliances are mainly an ex post indicator of a patron's commitment to a client, arm transfers are primarily an ex ante signal of such a commitment—the costs of which result from a patron supplying a loan or grant to its client to purchase weapons or directly providing arms.15 Arms transfers can signal a patron's intentions by demonstrating its interest in maintaining the security of its client. Three characteristics of arms transfers affect their signaling value. The first characteristic is the size of the arms transfer. A large transfer can function as a sunk cost. Such costly signals cause a client and its adversary to reason that only a patron with a strong interest in maintaining the security of its client would significantly augment its arsenal. We define the size of an arms transfer as the percentage of the patron's total military transfer budget devoted to a certain client relative to other regional clients.16 The second characteristic concerns the type of weapons being transferred. Defensive weapons limit the client's ability to conquer territory or to launch a first strike. By contrast, offensive weapons (i.e., those that favor mobility over protection or firepower) constitute a more costly signal.17 The adversary might even regard the patron's willingness to supply offensive weapons as a signal that the patron approves of a client's offensive aims. The adversary and other outside observers are therefore more likely to believe that the patron will come to its client's aid in a crisis. Alternatively, whatever the patron's intentions, an adversary might blame the patron for providing weapons that enabled its client to undertake offensive operations, thereby implicating the patron in the conflict and increasing the likelihood that the adversary will target the patron.18 Transferring offensive weapons to a client thus means that the patron is accepting a higher risk of entrapment. The third characteristic of arms transfers is institutionalization. The more institutionalized the practice of transferring arms, the stronger its signaling value. A single arms transfer is an ambiguous signal of a client's future commitment, because it provides limited information about the patron's future behavior. More institutionalized arrangements produce expectations of future weapons transfers, increase the anticipated cost of the client's commitment to the patron and the anticipated benefit to the client, and are much harder to reverse. With institutionalization, the patron is more likely to suffer reputation costs if its client is defeated. At stake is not the patron's reputation for resolve, but rather the patron's desire to be seen as being on the winning side. Institutionalized arms transfers can take many forms. Patrons might commit to provide a certain amount or type of arms within a specified time frame. Alternatively, patrons might offer some guarantee that their clients maintain a sufficient self-defense capability. By creating expectations of future arms transfers, institutionalization provides a new focal point for relations between the patron and its client. Thus, arms transfers convey the most significant and costliest signal of a patron's support when they include the institutionalized provision of a large quantity of offensive and defensive weapons.19 Costly arm transfers have at least two of these characteristics. When arms transfers are ad hoc and feature small quantities of defensive weapons, we argue that the signal conveys insignificant support. This conceptualization of arms transfers covers multiple methods of provision, including sales, grants, and loans. Although the payment mechanisms may differ, each type of arms transfer requires a similar set of decisions by the patron's leaders. In the United States, for example, both foreign military sales and financing are governed by the Arms Export Control Act, determined by the secretary of state, and executed by the secretary of defense. The president must formally decide that providing arms will “strengthen the security of the United States and promote world peace.”20 The central policy questions are similar even though the exact structure of each arms transfer arrangement may differ. Arms transfers have disadvantages that limit their deterrence, defense, and signaling value. First, arms transfers provide a quick solution to slight shifts in the local conventional military balance, but they cannot rapidly induce large changes in a client's wartime military capabilities relative to a much more powerful adversary. The supply of arms is unlikely to achieve battlefield results similar to intervention by a major power. When the client faces a significant disadvantage and thus cannot deter or defend against an adversary, the transfer of weapons might be insufficient to turn the tide of a conflict. It could, however, buy the client time while the patron decides whether and how to intervene. A second limitation is that ex ante arms transfers do not constitute a promise to rescue the client in a militarized crisis, though they could entangle a patron perceived as complicit in a conflict. The steady supply of significant military arms could establish the perception of a close partnership between the patron and its client, but such partnerships typically do not include an explicit commitment from the patron to support its client in wartime. Therefore, relative to formal alliance commitments, even significant arms transfers are unlikely to entrap a patron concerned about its reputation. ### Theoretical Framework To highlight the patron's dilemma, and to explain the complementarity and substitutability of arms transfers and alliances, we offer a new theoretical framework. Building on the realist observation that threat perceptions drive alliance formation, our theory emphasizes two independent variables, both of which are perceptual. The first independent variable is the patron's assessment of the commonality of security interests with a potential client. The second is the patron's assessment of the client's military capabilities relative to a shared adversary.21 We argue that patrons assess these two variables in turn. Commonality of security interests refers to the extent of the threat that the client's primary adversary poses to the patron's core security interests. This variable is perceptual because it depends on decisionmakers' threat assessments. In situations of high compatibility of interests, the patron must determine whether its client's most severe security threat also poses a significant threat to the patron's core security interests. The patron must also determine whether the client is in an adversarial relationship with a third country with which the patron has an alliance or wishes to improve diplomatic relations. If the client is not in such a relationship, then the security interests of the patron and the client will be highly compatible, making the patron more likely to sign a formal defense pact with its client than not. A formal alliance is attractive for clarifying the deterrent signal for adversaries, protecting the alliance from changes in government, and facilitating military-to-military cooperation in peacetime.22 In these situations, the patron will regard such a commitment as enhancing its own security and will be less concerned with entrapment.23 An example of a patron and a client exhibiting highly compatible security interests is the case of the United States and West Germany. Both countries saw the Soviet Union and its allies as their principal adversaries during the Cold War, and West Germany did not face another significant adversary. In relationships with limited compatibility, the primary threat confronting the client does not appear to pose a threat to the security interests of the patron. Divergences in security threats are also significant for the patron when the enemy of its friend is also its friend, thereby complicating the making of a hand-tying commitment—that is, a commitment that constrains future decisions. All else being equal, we expect alliances that are based on only limited common interests to exhibit a lower level of commitment compared with those based on high commonality, because the patron prefers not to be involved directly in the disputes that the client has with unshared adversaries. In such situations, an unconditional formal defense treaty between a patron and a client is very unlikely.24 An example of a security relationship with limited compatibility is that between the United States and Saudi Arabia. Although Iranian nuclear capabilities have long concerned both countries, Saudi Arabia has significant security concerns that the United States does not share, including Israel. Consequently, no formal U.S.-Saudi defense treaty exists.25 Our second independent variable is the client's military capabilities. The patron evaluates whether the client can effectively deter an attack from the client's main adversary and prevail militarily if deterrence fails. In this situation, the patron conducts a net assessment that combines quantitative measurements and qualitative indicators to infer the strength of the opposing militaries. It must consider dynamic and contextual factors that affect the client's capabilities in both the present and short terms. When the client enjoys a favorable military balance, a transfer of arms could encourage the client to undertake offensive operations. In such situations, particularly when the patron and the client have a formal alliance, the patron is unlikely to transfer arms that could embolden its client and thereby entrap the patron. When the client's military capabilities are low relative to those of its adversary, however, arms transfers could enhance the client's deterrence and defense capabilities while signaling the patron's support. An example of a U.S. client with high (conventional) military capabilities is South Korea relative to North Korea. An example of a U.S. client with low military capabilities is Taiwan relative to China.26 Before describing the predicted outcomes generated by interacting these two variables, we must clarify our assumptions. First, we assume that the patron always wants to preserve the status quo between the client and the client's adversary. Indeed, the patron faces an optimization problem: it wants to deter an adversary from challenging its client (and ensure the client's ability to prevail if deterrence fails) but at the lowest possible cost. Second, we assume that the client wants to extract the greatest commitment possible from its patron, regardless of the form it takes.27 Figure 1 displays our four predicted outcomes. Consider, first, the situation in which the patron perceives highly compatible security interests but the client faces an unfavorable local military balance (the top-left cell). Because their security interests overlap and the client needs military assistance, the patron will provide its client both costly arms and a defense pact. In this scenario, a defense pact is desirable because it issues a strong deterrent signal to adversaries, facilitates military-to-military coordination, and sustains the partnership against changes in either government. Arms transfers bolster the deterrent value of the alliance by making the ally more capable of at least holding off potential aggressors until reinforcements arrive.28 Figure 1. The Patron's Dilemma Figure 1. The Patron's Dilemma The second situation involves highly compatible security interests but a military balance that favors the client rather than the adversary (the top-right cell). For the patron, providing costly arms would be redundant and even dangerous because it could encourage the client to press its claims against the adversary.29 In this scenario, the patron would still provide or maintain an alliance commitment to deter the common adversary. The alliance offers some leverage over the client and a hedge in case the client's relative military advantage suddenly deteriorates. Although alliances carry some costs and risks, they remain a more cost-effective way of thwarting aggression against the client than having to intervene on behalf of a non-treaty security partner should local deterrence fail. To minimize moral hazard, however, the patron could add conditions to the alliance to ensure that it is activated only after an unambiguous attack on its client. For the client, notwithstanding its relative military preponderance vis-à-vis the adversary, an alliance with the patron remains attractive because it enhances deterrence, reduces the risk of a simultaneous attack by multiple adversaries, and lowers the overall cost of providing for its own defense by way of burden-sharing. In the third and fourth situations, the patron and the client have only somewhat compatible security interests. Although the patron does not wish to leave its client vulnerable, it does not want to provide the client with an unconditional defense pact for fear of getting entrapped in a conflict with an unshared enemy. If the patron were to offer a commitment, then it would at most be a highly conditional defense pact to reduce this entrapment risk. Designing conditional defense pacts is difficult, however, because clarifying the terms of assistance could invite either the client or the adversary to skirt the treaty. Such pacts are also difficult to implement because when a conflict breaks out, it is often unclear which state was the primary aggressor. Also, adversaries might find conditional alliances threatening. Consequently, the patron could abrogate the alliance to reassure the courted adversary.30 Whether the patron transfers costly arms in these two situations depends on its assessments of the client's military capabilities. When the patron concludes that the military balance is unfavorable to the client (the bottom-left cell), the patron is likely to send costly arms to enable the client to deter its main adversary. If the patron desires cooperative relations with that adversary, then relying on arms transfers can also signal continued diplomatic support without a commitment to intervene militarily. Still, the patron will likely prefer to transfer weapons that would reduce instability and hence potential entrapment risks, thus supplying defensive rather than offensive weapons.31 The resulting ambiguity still has deterrent value: potential challengers might refrain from attacking the patron's client if they cannot be sure how the patron will aid the client in response. Moreover, the relative flexibility of arms transfers is advantageous for the patron when it desires the cooperation of both its client and that client's adversary. By providing arms to both parties, the patron could extract mutual concessions and create strategic ambiguity about which side it would support in a crisis, thereby decreasing the chance for war.32 Finally, if the patron and the client have somewhat compatible security interests and the patron assesses that the military balance is favorable to the client (the bottom-right cell), costly arms are unnecessary. Arms will probably offer marginal deterrent value but nevertheless allow the client to sabotage the patron's efforts to avoid regional conflict or pursue relations with the client's adversary. Anticipating these dangers, the patron will likely withhold both an alliance and costly arms. The patron is likely to consider an alliance undesirable because the client's interests do not overlap sufficiently with those of the patron and the client is militarily superior to its main adversary.33 The patron might still choose to arm its client occasionally if it believes that the client's deterrent capabilities are likely to erode in the near future, but such transfers will be sporadic, relatively limited, and restricted to defensive weapons. If the patron believes that its client has revisionist intentions, then its fears of entrapment will be greater. The patron's security commitments will mirror those shown in figure 1. But because of its concerns about entrapment, the patron will increase the number or type of conditions attached to its alliance with the client, and it will impose limitations on arms across all cells. Thus, the higher the degree of conditionality, the lower the moral hazard. Alliance conditions could appear in secret annexes either to render them invisible to potential domestic opposition groups or because the patron wishes to maintain the deterrent value of the alliance. ### Research Design and Alternative Explanations Using primary documents and newly declassified materials from the presidential libraries of Richard Nixon, Gerald Ford, and Jimmy Carter, we test our theoretical predictions. We focus on U.S. commitments to two client states: Taiwan and Israel. These historically important cases allow us to test the causal mechanisms of our theory.34 Each case features significant variation in one of our independent variables over time. In the Taiwan case, our first independent variable—commonality of security interests—changes in value. In the Israel case, our second independent variable—the patron's assessment of its client's military capabilities—changes in value. The extensive documentary evidence in each case permits us to process trace how perceived shifts in threats and client capabilities causally affected the commitments the United States offered its clients. Moreover, because neither client had credible alternative sources of patronage, both were beholden to the United States, thus validating our exclusive focus on U.S. decisionmaking and our decision to hold client preferences constant. Finally, our theoretical framework highlights the role of threat perceptions and military capabilities, but we recognize that other factors could affect arms transfer and alliance decisions. We have selected cases that are relatively “easy” for the domestic political and commercial motivations arguments because they involve countries with major political lobbies in the United States as well as large arms packages for which strong commercial interests would be at stake. By examining both Democratic and Republican administrations, we take into account potentially confounding variables. ### U.S. Commitments to Taiwan Taiwan today occupies an ambiguous place in the U.S.-led security order in East Asia.35 At one time, however, its security relationship with the United States was much more clear-cut. In 1954, the United States formed an alliance with, and began sending costly arms to, Taiwan to contain communist expansion. No direct high-level ties existed between the United States and China until sweeping changes took place during Richard Nixon's presidency, culminating in his famous 1972 visit to Beijing. In 1979, the United States normalized relations with China and ended its alliance and formal diplomatic ties with Taiwan while maintaining its policy of arms transfers. Our theory predicts that before normalization, the United States would have coupled an alliance commitment to Taiwan with a steady supply of costly arms (figure 1, upper-left cell). During this period, the United States and Taiwan had common security interests, as both were highly concerned about the Chinese communist threat. U.S. threat perceptions changed dramatically in the early 1970s, however, as growing tensions in the Sino-Soviet relationship allowed the United States to use China for containing the Soviet threat. Accordingly, U.S. interests diverged from those of Taiwan, resulting in the United States' rapprochement with the mainland. Following normalization, costly arms transfers to Taiwan should have become the United States' preferred means of signaling reassurance and practicing deterrence (figure 1, bottom-left cell). #### COMMON INTERESTS: RELATIONS BEFORE NORMALIZATION WITH CHINA In the early 1950s, U.S. policymakers assessed that mainland China was a primary threat to the United States and that it was stronger militarily than the Republic of China in Taiwan. Driven from the mainland, Chiang Kai-shek's Nationalist government became a bulwark against communism during the Korean War. President Harry Truman provided Taiwan with economic aid and deployed the U.S. Seventh Fleet to neutralize the Taiwan Strait, thereby preventing cross-strait attacks by either Taiwan or China. Truman's successor, Dwight Eisenhower, viewed Taiwan as central to the United States' Asia policy. Eisenhower thought that Taiwan's “existence, under American protection, was essential in maintaining the belief in Asia that the mainland juggernaut could be stopped and that the United States would stand by its anticommunist friends.”36 Eisenhower therefore lifted Truman's neutralization policy toward the Taiwan Strait, allowing Chiang's forces to fortify the islands of Quemoy and Matsu off the mainland's coast. These developments prompted China to begin shelling Quemoy in August 1954.37 Chinese media declared contemporaneously that “China must liberate Taiwan.”38 Alarmed by China's belligerence, the United States signed a Mutual Defense Treaty with Taiwan on December 2, 1954. The treaty required the United States to defend Taiwan if the main island of Formosa or the outlying Pescadores Islands were attacked. In exchange, the treaty permitted the United States to base troops on Taiwan's territory.39 Concerned about Taiwan entrapping the United States in a conflict, Washington insisted on a secret provision stipulating that the United States would assist Taiwan only for its defense.40 In 1954, the Eisenhower administration conditioned the transfer of F-84 fighter-bombers to Taiwan, pledging restraint.41 Moreover, the treaty did not explicitly oblige the United States to defend the offshore islands closer to the mainland, suggesting that it would do so only if the main islands of Formosa and Penghu were threatened. U.S. decisionmakers in private, however, made explicit commitments to Chiang to defend some of the offshore islands.42 In late January 1955, Eisenhower supported legislation—the Formosa Resolution—that granted the president the authority to intervene militarily on behalf of Taiwan should it be attacked.43 Early that year, U.S. decisionmakers even intimated that the United States would use nuclear weapons to defend Taiwan against China.44 Although Washington and Taipei sometimes disagreed on strategy toward Beijing, even clashing over whether to use military force against the mainland, both viewed China as a significant threat. In 1956, during a visit to Taipei, President Eisenhower noted: “There is no way in which Asia can be free of communism until mainland China is free.” Furthermore, he suggested that “it was time to work out the strategy for liberating Asia.”45 John Foster Dulles commented, “The Chinese Communists seem to be much more violent and fanatical, more addicted to the use of force than the Russians are or have become.”46 Beijing's aggressive behavior required a response to reinforce Taiwan's security, which, Robert Accinelli notes, “was critically dependent on U.S. aid and backing.”47 The United States augmented Taiwan's defenses by providing defensive military assistance. In December 1956, U.S. policy toward Taiwan was crystallized in NSC (National Security Council) report 5503, which asserted that the United States should “not agree to [Taiwan's] offensive actions against mainland Communist China.”48 It would, however, provide defensive arms and station nuclear-capable Matador missiles on Taiwan.49 Notwithstanding the United States and Taiwan's highly compatible security interests, Chiang's rhetoric and actions suggested that he might entangle the United States in a war with China to facilitate the Nationalists' return to the mainland.50 A 1957 U.S. National Intelligence Estimate (NIE) warned that although in the next year “Chinese Nationalists are very unlikely to launch an invasion … the Nationalists might attempt within the period of this estimate to embroil the U.S. in major hostilities against the Chinese Communists.”51 And so, despite his desire to appear resolute against China, Eisenhower had to consider the possibility of entrapment. Accordingly, Eisenhower sought assurances that Chiang would renounce the use of force to unseat mainland communist leaders.52 Rather than providing Taiwan with potentially offensive weapons when Chinese forces shelled the Quemoy and Matsu Islands during the 1958 Taiwan Strait crisis, the United States deployed its own forces. Eisenhower ordered a massive force to Taiwan, including F-100 and F-86 aircraft, the latter of which was equipped with air-to-air Sidewinder missiles so as to signal U.S. determination.53 Clarifications were needed, however, regarding whether “[t]he intent of NSC 5503 was to oppose the development of [Taiwan's] forces to conduct offensive operations against mainland Communist China.”54 To simplify this issue, Eisenhower directed: “We should provide Chiang Kai-shek with a limited capability in terms of amphibious equipment, but we should concentrate our assistance on the provision of defensive equipment.”55 In the following years, the United States would provide Taiwan tactical fighter aircraft and smaller surface vessels, but no large-scale amphibious capabilities such as troop transports.56 U.S. officials were concerned that amphibious transports, combined with long-range bombers, could provide the mobility Taiwan required to invade the mainland. According to the U.S. embassy in Taiwan, a “request for B-57's and landing craft” was “war material obviously of an offensive character…. Its aggressive nature is self-evident.”57 Later in 1962, Assistant Secretary of State for Far Eastern Affairs Averill Harriman asked the U.S. ambassador to Taiwan to “clearly state our unwillingness [to] provide these items.”58 Although scholars express concern about the distinguishability of offensive and defensive weapons, the primary documents indicate that policymakers dealing with military assistance to Taiwan differentiated between those weapons that would provide Taiwan with an invasion capability and those that would not.59 Throughout the 1960s, the U.S. intelligence community assessed that China was stronger militarily than Taiwan, but leaders in Washington remained concerned that Chiang might attempt an attack on the mainland.60 Divergence over preferred strategies and political goals gave rise to mutual distrust and suspicion. In 1962 and 1963, President John Kennedy restrained Chiang from launching attacks on China,61 and a 1964 National Policy Paper warned that Taiwan's “dependence on the U.S. for its very existence will continue, in the final analysis, to provide the principal basis for U.S. influence. We face, however, the problem of adjusting to the declining importance of two of the specific instruments—our economic and military aid programs—through which we have made our influence felt.”62 Indeed, from 1951 to 1966, the United States provided Taiwan with a large quantity of military assistance, amounting to more than$2.4 billion in value. Such sales helped bolster Taiwan's defensive capabilities, assured Taiwan of continued U.S. support, and deterred Chinese military action across the strait, while providing the United States with additional influence over the Nationalist government.

Also throughout the 1960s, “the United States and China both held extreme views of the other's strategic, long-term objectives and potential threat to their respective security.”63 By the end of the Kennedy administration, U.S. leaders were contemplating military strikes against Chinese nuclear facilities.64 Chinese leaders publicized their intention to eliminate Chiang's government, likely through military action.65 In response, Secretary of State Dean Rusk reiterated that the U.S. commitment to Taiwan was “not open to negotiation.”66 This sense of a Chinese threat was rooted not only in Chinese military and economic capabilities, but also in China's “Maoist revolutionary propaganda and … popularity of the Maoist economic model in the Third World.”67 Nevertheless, President Lyndon Johnson worried about reports that Chiang believed “now is the time for [Taiwan] to attack and overthrow the Chinese Communist regime on the Mainland.”68 In fact, Chiang's vice president had gone so far as to tell Johnson: “We have our aspirations” about regaining the mainland.69 Thus, U.S. leaders sought to provide Taiwan an alliance, but not offensive arms, through the late 1960s.

#### DIVERGENT INTERESTS: RELATIONS AFTER RAPPROCHEMENT

The eruption of a Sino-Soviet border conflict in 1969 worsened relations between Beijing and Moscow, convincing President Richard Nixon and National Security Adviser Henry Kissinger that a conciliatory approach to China suited U.S. strategic interests.70 Moreover, growing incompatibility in the security interests of the United States and Taiwan led U.S. leaders to end the alliance with Taiwan and to rely only on arms transfers.

In the early 1970s, the United States assessed that the local balance of power continued to favor China. The Chinese had begun their nuclear program in 1955, carried out a nuclear test in 1964, and were building a deterrent force by the late 1960s.71 Meanwhile, the Nixon Doctrine, which called on U.S. allies to bear more of the conventional defense burden, meant that Taiwan would receive less support from the U.S. military than it had previously. One report noted that “China could almost certainly take Taiwan in the absence of U.S. military intervention … [but] Peking would be constrained by the necessity of providing for defense needs elsewhere.”72 Recognizing Taiwan's insecurity, one internal U.S. memorandum cautioned that “a sudden drop in the U.S. military presence on Taiwan that exceeded reductions consonant with our withdrawals from Viet-Nam should probably not be taken.”73 In 1974, they commented: “[Taiwan] has thus shown increasing resignation to the inevitability of a growing [Chinese] military superiority.”74 Throughout this period, however, they continued to believe that China could not launch a successful invasion across the Taiwan Strait.

U.S. leaders did worry that perceptions of U.S. irresoluteness would inspire Chinese aggression.75 Yet they also worried that Taipei might seek to spoil a U.S.-China agreement by initiating a conflict with the mainland. In a July 1971 discussion with Kissinger, Chinese Premier Zhou Enlai warned that although “[i]t's not possible for them to send troops en masse … there are those among his troops who deliberately want to make adventures—deliberately to create trouble for him, and for you.”76 To address these concerns, Taiwan assured the United States that it would not seek revisionist goals through military means in the near term. The vice premier told Nixon in April 1970, “[Taiwan] will not use armed force against the mainland, even on a small scale.”77 In 1972, under pressure once again from Kissinger and other U.S. officials, Chiang Kai-shek gave “categorical assurances that [Taiwan] would refrain from any actions of an offensive or provocative nature” around Nixon's visit to China.78 Washington was adamant about these assurances, with the U.S. ambassador to Taiwan warning that actions by Taiwan or its sympathizers on the mainland “would put [Taiwan] in position to be plausibly blamed for untoward incident.”79

Courting China while calibrating U.S. policy toward a militarily disadvantaged Taiwan proved a delicate balance. China's eight demands for improving relations with the United States included the statement that “[a]ll U.S. armed forces and military installations should be withdrawn from Taiwan and the Taiwan Strait area…. [The United States] must recognize [China] as the sole legal government representing China.”80 To reassure and to deter China simultaneously, Kissinger took several “symbolic steps.” He explained to his Chinese interlocutors, “We have ended the Taiwan Strait Patrol, removed a squadron of air tankers from Taiwan, and reduced the size of our military advisory group by 20 percent…. We are prepared to begin reducing our other forces on Taiwan as our relations improve, so that the military questions need not be a principal obstacle between us.”81 Kissinger did not inform Zhou that the United States would increase the amount of military assistance it provided Taiwan despite the U.S. troop withdrawals. Therefore, the United States could appear to be decreasing its military support while increasing Taiwan's defensive capabilities.

The United States continued to provide costly military systems to Taiwan during the 1970s. It did not transfer troop transports that would help Taiwan launch offensive amphibious operations against China, but U.S. leaders allowed Taiwan to purchase Hawk surface-to-air missiles and permitted the co-production of F-5E fighter aircraft. These systems were not as technologically advanced as Taiwan desired, but they conveyed a sustained U.S. commitment, even after the United States' rapprochement with China in 1972 (see table 1).

Table 1.

Planned U.S. Military Assistance to Taiwan, 1972–76

Fiscal Years ($million) 19721973197419751976 Foreign military sales credit 45 44 65 135 124 Military assistance/aid program 11 10 5.8 5.8 0.5 Enhance Plus grant (Vietnam related) — 18 28 — — Total 56 72 99 141 125 Fiscal Years ($ million)
19721973197419751976
Foreign military sales credit 45 44 65 135 124
Military assistance/aid program 11 10 5.8 5.8 0.5
Enhance Plus grant (Vietnam related) — 18 28 — —
Total 56 72 99 141 125

SOURCE: “Memorandum from Richard T. Kennedy of the National Security Council Staff to the President's Assistant for National Security Affairs (Kissinger),” April 7, 1973, in Foreign Relations of the United States, 1969–1976, Vol. 18: China (Washington, D.C.: Government Printing Office), p. 240.

Costly U.S. arms sales to Taiwan persisted after the U.S. alliance commitment dissolved. Because Washington worried that “Peking would be bothered by an indefinite and formal U.S. military involvement with Taiwan,” it sought to avoid “weapons which were clearly offensive in nature (e.g., strategic bombers, long-range missiles, or modern amphibious equipment) … sophisticated weapons (e.g., advanced aircraft or major missile production capabilities); the most advanced weapons in the U.S. inventory (e.g., F-15 aircraft, TV guided bombs, advanced ECM [electronic counter-measure] systems) … [or] rapid introduction of large quantities of weapons into Taipei's inventory.”82 U.S. officials still believed that they could differentiate between offensive and defensive weapons and avoid transferring them. The United States wanted Taiwan to have “an Air Force designed primarily for air-to-air capability against fighters, bombers and airlift forces, and for countering a PRC naval attack; a navy capable of withstanding attacks by PRC submarine forces and missile-equipped surface craft and of countering PRC amphibious forces in coordination with the [Taiwan] Air Force; a relatively small but mobile and well-equipped [Taiwan] Army, including surface-to-air missiles for air defense, backed by a trained reserve force.”83 In suggesting how the United States could help develop Taiwan's forces, a 1974 U.S. government memo listed several criteria: “1) the impact on our objective of reducing the military component of Taiwan's security; 2) the effect on U.S.-PRC normalization; 3) the effect on Taiwan's confidence and stability; 4) the deterrent effect against a PRC use of force to resolve the Taiwan issue; 5) the effect on chances of [Sino-Taiwan] political accommodation; 6) [Taiwan's] economic and technological capabilities.”84

Public statements by U.S. officials now featured what Kissinger called “constructive ambiguity.” The “one China” policy and the Republic of China's removal from the United Nations in 1971 were heavy political blows for Taiwan. These developments prompted concern that “[d]esperation engendered by the feeling that we were completely abandoning Taiwan in proceeding with normalization might provoke [Taiwan's] declaration of independence.”85 U.S. officials privately tried to reassure Taiwan's leaders of continued U.S. support, but it became clear by the late 1970s that the United States would normalize relations with China and end formal diplomatic ties with Taiwan. Responsibility for normalization fell to the Carter administration.86 It wanted to provide enough arms for Taiwan to deter China and to ensure peaceful cross-strait relations.87 A 1976 NIE found that neither side could launch an offensive operation across the strait without incurring unacceptable costs. This situation of mutual deterrence was to hold until at least the early 1980s.88 Nevertheless, the United States had to walk a fine line in balancing its regional interests.89 A 1978 joint State and Defense Department memorandum on arms sales to Taiwan advised, “Taiwan's self-defense capability will continue to be linked to its ability to buy arms from the U.S…. There are some indications that Peking views our existing relationship to Taiwan as a deterrent to Taipei's looking elsewhere for support, or seeking unilaterally to alter the island's status…. We do not wish to so arm [Taiwan] that we do damage to our relations with [China] or that we encourage [Taiwan] to behave without restraint toward [China]. In short, our arms sales must be carefully calibrated to maintain an adequate balance in the Strait.”90 Although China still faced significant challenges in mounting cross-strait operations, the local balance of power was shifting further in its favor. Secretary of State Cyrus Vance noted in 1977, “For a number of years, Peking will not be capable of taking the island by force except at a cost it would probably consider unacceptable both in military terms and in terms of China's international relations.”91 Nevertheless, “PRC military strength will increase over time,” requiring a new approach to prevent cross-strait conflict.92 Accordingly, U.S. decisionmakers believed that arms transfers to Taiwan could substitute for the alliance.93 Carter himself noted, “For a long time—with arms purchases—Taiwan will be able to withstand any attack.”94 The Carter administration mistakenly believed, however, that China would not protest the United States' continued transfer of weapons to Taiwan. It had to disabuse Chinese leaders of the belief that normalization would cease all U.S. arms transfers to Taiwan.95

On December 15, 1978, Washington instructed the U.S. ambassador to Taiwan to tell Chiang that the United States and China “have agreed to establish diplomatic relations…. the United States will recognize the People's Republic of China as the government of China.”96 The same cable instructed the ambassador to reassure Chiang that in a year he would “be able to resume purchase of carefully selected defensive weapons.”97 Yet U.S. decisionmakers hesitated when they received Taiwan's request for fighter jets. They wanted to reassure China of bona fide U.S. intentions for rapprochement.98 By this time U.S. officials had assessed that “China is now actively engaged in attempting to build a durable, world-wide anti-Soviet consensus.”99 Ultimately, the United States agreed to offer Taiwan the “limited range” F-5, but decided against more capable F-4s and F-16s.100 This decision aligned with the NSC staff's suggestion to reinforce “our willingness to put Taiwan in a better position to defend itself while protecting the Administration against charges that it is abandoning Taipei…. We should, therefore, indicate at an early date our willingness to sell a Hawk missile battalion, a substantial number of additional F-5E aircraft, and, perhaps, the Harpoon missile system to [Taiwan]. This would provide reassurance to Taipei, ease the concerns of Taiwan's friends in the U.S., and send the right signal to Peking.”101 U.S. leaders believed that such steps were reasonable because the arms were “defensive in character and could be applied to meet Taiwan's legitimate security needs without unduly damaging our relations with [China].”102

Whatever its intent, the Carter administration failed to anticipate Congress's negative reaction regarding the lack of consultation on the termination of formal diplomatic relations with Taiwan in 1979 and the end of the Mutual Defense Treaty in 1980. Members were also outraged because they perceived Carter's actions as abandoning an ally and damaging the United States' reputation. Indeed, shortly after China received diplomatic recognition from Washington, it invaded North Vietnam—an action that amplified the concerns expressed in Congress.103 The Taiwan Relations Act (TRA), which came into force on April 10, 1979, committed the United States to provide Taiwan with “arms of a defensive character … in such quantity as may be necessary to enable Taiwan to maintain a sufficient self-defense capability … based solely upon their judgment of the needs of Taiwan.”104 The TRA also required that Washington maintain the capacity to “resist any resort to force or other forms of coercion that would jeopardize the security, or the social or economic system, of the people of Taiwan.”105 Nevertheless, the TRA differed from an alliance because it did not commit the United States to defend Taiwan. Rather, “[t]he President and the Congress shall determine, in accordance with constitutional processes, appropriate action by the United States in response to any such danger.”106 In addition, the TRA did not stipulate which weapons would be sold to Taiwan, how often, or in what quantity. Its purpose instead was to reassure Taiwan of U.S. diplomatic support despite the termination of a formal defense pact. Its inherent ambiguities were intended to address three U.S. goals: to convey support for Taiwan, to support local deterrence and defense, and to continue normalization with China.107

U.S. leaders still faced a dilemma after the TRA came into force. China cautioned in the spring of 1979 that “[i]f things which will bring severe harm to this political basis are allowed to happen again and again, it will bring harm to our bilateral relations.”108 In a memorandum to President Carter, Secretary of State Vance noted: “We have a dual problem in determining our position on the resumption of arms sales to Taiwan. On the one hand, our action should be taken in such a way as to reassure Congress and Taiwan that we continue to have an interest in Taiwan's legitimate defense requirements. On the other hand, we wish to avoid provoking the PRC to react in a manner harmful to our developing bilateral relationship.”109 Nevertheless, Vance warned: “Taiwan views our arms sales commitment as the keystone of their security policy and will be anxious for reconfirmation of our pledges early in the new year.”110 Indeed, on November 8, 1979, Taiwan placed a request for “high-performance fighter aircraft … with most other requests focused on air and sea defense weapons.”111 U.S. officials now reconsidered selling F-4s to Taiwan, noting that “F-4 sale would dramatize that the U.S. is not ‘abandoning’ Taiwan…. Both with Congress and on Taiwan, an F-4 sale is probably the most popular step we can take.”112 Responding to Taiwan's demands, however, Vance reasoned in December 1979 that an upgrade in the U.S. military commitment to Taiwan was unlikely. To him, there was “no reason at this point to change our position of denying sales to Taiwan of F-4, F-16 or F-18 aircraft, all of which have offensive capability as well as violate the arms transfer policy.”113

Despite U.S. concessions to China, Reagan took several actions to demonstrate his intention to support Taiwan's security. Many documents from the Reagan years remain classified, but available primary documents and secondary sources indicate that Reagan wished to redirect U.S. policy toward Taiwan. First, he authorized Taiwan to publicly release his “six assurances,” which included commitments that the United States would not alter the terms of the TRA, that the administration would not consult the Chinese government in advance of arms sales to Taiwan, and that the United States would not pressure Taiwan to negotiate with China. Former U.S. Ambassador to China James Lilley suggests that these efforts “were designed to be a sign to Taiwan that it was not going to be abandoned by the Reagan administration…. The assurances cushioned the anxiety and uneasiness of the Taiwan leadership.”116 Reagan also provided an even more forceful private assurance to Taiwan's leadership that the United States was committed “to the security and wellbeing of its people” by promising to provide it with “sufficient arms to enable Taiwan to maintain a sufficient self-defense capability.”117 An additional step apparently intended to ensure the long-term viability of U.S. Taiwan policy was Reagan's issuance of a classified presidential directive that incorporated his interpretation of the communiqués. The directive noted that “the U.S. willingness to reduce its arms sales to Taiwan is conditioned absolutely upon the continued commitment of China to the peaceful solution of the Taiwan-PRC differences…. It is essential that the quantity and quality of the arms provided Taiwan be conditioned entirely on the threat posed by the PRC.”118

None of these commitments was as binding as the Mutual Defense Treaty had been. They left significant room for interpretation of Taiwan's future defense needs. Reagan merely promised that Washington would “continue to monitor carefully Beijing's military production and deployment, and to analyze all indicators of Beijing's intentions toward Taiwan. If any of those factors change, that will of course affect our judgment of Taiwan's defense needs.”119 Still, the combination of U.S. public and private pledges of reassurance, together with the extension of the F-5E co-production line and a substantial arms sales package, tempered Taiwan's reaction to the 1982 Joint Communiqué without rupturing U.S. relations with China. Reagan's policies effectively sought to substitute the hand-tying commitment the United States had with Taiwan before normalization with one that gave the United States more flexibility. This policy reassured Taiwan while the United States courted China.

#### SUMMARY AND ALTERNATIVE ARGUMENTS REGARDING THE TAIWAN CASE

The Taiwan case confirms our theory. When U.S. leaders assessed that China posed a significant security threat to U.S. interests, they entered into a formal defense pact with Taiwan and supplied it with costly arms to preserve its deterrent capabilities (top-left cell of figure 1). But when the Sino-Soviet split made normalization with China possible, U.S. leaders' perception of the threat from China changed. More friendly relations with the Chinese government decreased the U.S. perception of the military threat from China to U.S. forces in East Asia. Moreover, the U.S. withdrawal from Vietnam made Taiwan less vital as a forward staging area for U.S. forces deploying to Southeast Asia. The commonality of security interests between the United States and Taiwan subsequently decreased.

As our theory predicts, the United States engaged China and rescinded its alliance with Taiwan despite the worsening military balance between China and Taiwan. Nevertheless, the United States continued to provide Taiwan with substantial military assistance to maintain the status quo across the strait. Consistent with our theory, the United States provided a large, steady, and (with the TRA) institutionalized flow of weapons to Taiwan (top-right cell of figure 1). The provision of arms remained limited to defensive weapons, especially when U.S. leaders worried that Taiwan's military was planning or preparing for an offensive against the mainland.

Our research finds little evidence that U.S. decisionmakers were motivated primarily by other factors, such as domestic politics or commercial interests. Regarding domestic politics, the documents reveal that U.S. decisionmakers were keenly aware of the domestic constraints on Taiwan policy. As a White House memo noted in 1978, “There is no domestic constituency actively pushing for or even interested in normalization, but there is such a constituency vigorously opposing it. Thus, there is no political plus in normalization; there is only minus.”120 Despite this domestic political opposition, the United States abrogated its defense pact with Taiwan. We do not suggest that U.S. domestic politics played no role in Washington's relations with Taipei. Indeed, domestic politics prompted the creation of the TRA: had it not been for Congress, U.S. defensive weapons sales might not have been institutionalized. Nevertheless, as Carter's national security adviser, Zbigniew Brzezinski, observed at the time: “Until the mid-1960s, the Taiwan Lobby was thought to have great political clout. Then, in the late sixties and even more after Nixon's 1972 visit, the Lobby fell into disarray.”121 The Taiwan lobby's inability to maintain the alliance is evidence that it was a secondary concern for policymakers. As Brzezinski noted in 1977, “The Taiwan Lobby does not constitute a major obstacle to normalization.”122 In short, the strategic interest in normalization with China was greater than the domestic political power of the Taiwan lobby. Similarly, government reports regarding the advantages and disadvantages of providing arms to Taiwan seldom mention either commercial interests or influence-seeking. Both motivations could have been considerations for policymakers, but the lack of discussion about them in interagency meetings forces us to question their importance. U.S. leaders understood that Taiwan had few other sources of support, so it was unlikely to abandon the United States. Moreover, leverage-seeking does not explain why the United States chose to end its official relationship with Taiwan in the 1970s. Therefore, although domestic politics, commercial interests, and leverage-seeking may have driven some U.S. decisions on Taiwan, the evidence suggests that strategic considerations primarily motivated U.S. policymakers. (See figure 2 for a summary of our predictions and evidence.)

Figure 2.

Summary of Predictions and Evidence for Taiwan

Figure 2.

Summary of Predictions and Evidence for Taiwan

### U.S. Commitments to Israel

Few today doubt the United States' close alignment with Israel. Yet, during the first half of the Cold War, this relationship was both uncertain and contingent. Although the United States had limited diplomatic relations with Israel in the 1950s, the Eisenhower administration eventually regarded Israel as a “potential strategic asset.” Nevertheless, both it and the Kennedy administration provided Israel only minimal defensive arms and extended no alliance commitment (the bottom-right cell in figure 1).123 Late in the Johnson administration and throughout the Nixon administration, the United States moved toward using costly arms transfers to improve and to maintain Israel's deterrence capabilities in the absence of an alliance (the bottom-left cell). U.S. leaders' commitment decisions hinged on assessments of the local military balance.

### FAVORABLE BALANCE: U.S.-ISRAEL SECURITY RELATIONS BEFORE 1968

On May 12, 1963, Israeli Prime Minister David Ben-Gurion wrote to President Kennedy asking for a public bilateral security pact or “all the equivalent kinds of armament with which the armed forces of Egypt and the other Arab states are equipped” in return for Israel forgoing a nuclear weapons capability.124 The letter came four days after Kennedy remarked at a press conference that the United States “support[s] the security of both Israel and her neighbors.”125 Ben-Gurion's letter prompted debate within the Kennedy administration over whether to extend an alliance to Israel. In considering this request, Kennedy thought that an explicit security guarantee could make Arab states more conciliatory and reduce uncertainty over U.S. intentions in the region.126

The evidence shows that the two factors highlighted in our theory drove the U.S. decision ultimately to reject Israel's request for a hand-tying commitment. First, the United States assessed that Israel was capable of deterring its adversaries without one. Kennedy's final reply noted that the United States had carried out an assessment of its own ability to “deter or halt swiftly any aggression against Israel” and found that “existing informal arrangements” were sufficient.127 The Joint Chiefs of Staff agreed that “there is little or no advantage to the U.S. in going beyond the type of public assurances contained in the President's May 8th statement.”128

A second, more fundamental, factor that limited U.S. commitments to Israel was the incompatibility of the two countries' security interests. Both Israel and the United States did not want Arab states to strengthen their ties with the Soviet Union.129 Nevertheless, the United States saw Arab nationalism as a potential bulwark against communism, whereas Israel saw it as a threat to its own security.130 The administration was thus reluctant to make a formal and public commitment to Israel for fear of damaging diplomatic relations with its Arab neighbors. As Kennedy wrote, “Our policies and programs in regard to the Arab states have resulted in improved relationships which permit us to talk frankly and realistically to them and enable us to exert some leverage on their actions.”131 The Kennedy administration was optimistic about working with Egyptian President Gamal Abdel Nasser on regional arms control and other issues. It saw a need to prevent the Middle East from being divided into the two superpower camps. Indeed, losing Egypt to the Soviet Union would diminish U.S. influence in the Arab word.132

Kennedy therefore rejected a defense pact with Israel, but did offer the Israelis a one-time, non-costly transfer of defensive Hawk missiles. Justifying the sale was a Defense Department memorandum that identified Israel as “vulnerable to [Egyptian] air attack … increasingly so with the arrival of additional Soviet TU-16's.”133 For Kennedy, the arms transfers were intended to maintain the local balance of power and deter Arab attacks. In a memorandum articulating his thinking, the president asked: “Could we get away with arms aid or joint planning in lieu of a guarantee? If we argue Israel doesn't really need any tighter assurances than it has already there may be other ways to prove we mean to protect her. Hawk set a precedent.”134 This provision of arms aside, the administration made clear that the United States did not want to become a “major supplier of offensive or sophisticated weapons to parties to the Arab-Israeli conflict. It is [a] single decision designed [to] meet [a] specific need for an improved air defense.”135 The reasoning used by the Kennedy administration thus accords with our theoretical predictions, placing U.S.-Israeli security cooperation circa 1963 in the bottom-right cell of figure 1.

The Johnson administration similarly saw Israeli and U.S. security interests as not compatible enough to justify a commitment that could undermine broader U.S. interests in the Middle East. Johnson began wrestling with the patron's dilemma when, in November 1963, Israel requested surface-to-surface missiles, tanks, and naval vessels. These weapons would have given Israel the capacity to strike Egyptian artillery locations and launch penetration raids into Egyptian territory. U.S. officials were skeptical as to whether Israel needed these weapons. One NIE early that year had concluded that “Israel will probably retain its overall military superiority vis-à-vis the Arab states for the next several years. As long as the present balance of forces remains substantially unchanged, we believe that neither side is likely to initiate major hostilities.”136 McGeorge Bundy, Johnson's special assistant for national security, argued that Israel's request was financially “wasteful” and “unnecessary” from a strategic perspective.137 The Joint Chiefs of Staff concurred, claiming that a “significant increase in Israeli Army units does not appear to be justified by the existing strength [sic] relationship between the Israeli and Arab Armies.”138 Meeting this request would have also antagonized Arab governments, especially because U.S. officials worried that the “good relations [the United States] has built up with the Arabs are in increasing jeopardy” given Arab tensions with Israel.139 In January 1964, the Departments of State and Defense affirmed the need to consider both Israeli and Arab interests because “the key to a constructive Near Eastern policy is maintaining a balance in our relationships with the Arabs and Israel.”140 The U.S. Joint Chiefs of Staff noted that U.S. arms policy could proceed “without positively identifying the United States with either of the sides in the Arab-Israeli conflict.”141

Johnson nevertheless sought to reassure Israel by maintaining non-costly arms transfers. Indeed, the United States recognized Israel's need for new tanks to preserve the local balance of power. A memorandum circulated by the Joint Chiefs of Staff stated that “there is a military need for Israel to modernize its tank force because the bulk of its tank inventory is obsolescent.”142 Other U.S. government officials, however, asserted that the “U.S. wishes to avoid significant area arms imbalance [sic] in either direction; if Israel attained clear military superiority a dangerous escalation would surely ensue.”143 Moreover, the United States had to consider the likely reaction of the Arab world, as “tanks from [the] U.S. would strengthen U.S. commitment to Israel in Arab eyes.”144 In a meeting with Israeli Prime Minister Levi Eshkol, Deputy Special Counsel Myer Feldman explained that “an important factor in these considerations was how the U.S. could best maintain and expand its influence in the Arab world.”145 Still, Washington did not want to leave Israel empty-handed. The U.S. government thus actively encouraged third-parties such as West Germany to supply tanks instead.146 Arms transfers done in this indirect manner enhanced Israeli security without compromising U.S. relations with the Arab states.147

On June 5, 1967, war broke out between Israel and Egypt, Jordan, and Syria. Israel captured the Sinai Peninsula and the Gaza Strip from Egypt, the West Bank from Jordan, and the Golan Heights from Syria, thereby reinforcing U.S. views that Israel faced a favorable military balance. Acting Secretary of State Nicholas Katzenbach informed President Johnson that “the military balance is in Israel's favor and should remain so for at least a year.”148 U.S. military observers agreed, pointing to Israel's air superiority and its success in destroying Arab “morale, motivation, and confidence”—intangibles that “cannot be recovered quickly.”149 Supporting this characterization is a secret NSC memo produced during Jimmy Carter's presidency that reviews the history of U.S. arms sales to Israel: “Up to the Six-Day War in 1967, the U.S. objective was to sell limited quantities of selected defensive weapons to Israel, such as the Hawk antiaircraft missile system.”150 That said, in the wake of this war, U.S. decisionmakers still saw Israel and U.S. security interests as only somewhat compatible. As our theory predicts, given the limited convergence of U.S.-Israeli security interests, and Israel's ability to continue deterring its regional adversaries, U.S. leaders were reluctant to become Israel's major arms supplier. They eschewed commitments to supply costly arms in the future, thereby placing the overall relations in the bottom-right cell of figure 1.

### SHAKY BALANCE! U.S.-ISRAELI SECURITY RELATIONS, 1968–73

The defeat of Arab states in the Six-Day War prompted the Soviet Union to significantly increase its involvement on their behalf. As a January 1968 NIE concluded, “Since the June War in 1967, the Soviet military presence has grown in the area: roughly 5,000 Soviet military advisers are now stationed in several area countries; the Soviet naval squadron in the Mediterranean has been strengthened, and is supported by air and port facilities in Egypt.”151 Johnson “express[ed] his deep concern over the odds working against Israel. He knew the Israeli people were superior in ability to their neighbors, but he feared they might not be superior to the Soviets. The President recalled how the Soviets had poured arms into the Arab countries after the war. He said he was not sure what Soviet intentions were.”152 Secretary of State Rusk observed several months later that “the influence of the Soviet Union in such key countries as Egypt, Syria, and Iraq continues to grow at the expense of our and other Western interests.”153 Yet Walt Rostow, Johnson's special assistant for national security affairs, explained that “the ‘overriding consideration’ must be our avoiding a polarization of the Middle East in which a small Israel, backed by a U.S. with an ambiguous commitment, faces the Arabs, led by extremists and backed by a determined USSR.”154

Against this backdrop, in early 1968 Israel requested additional aircraft from the United States, including F-4 Phantoms.155 The F-4 was among the most advanced in service and its firepower, speed, and adaptability would augment Israel's offensive capabilities. The A-4 Skyhawk, another aircraft that Israeli desired but found less appealing, was lighter, slower, and cheaper. Worried about the Arab reaction, the Johnson administration was reluctant to authorize the F-4 request. Rostow opined: “More than just seeking a specific number of aircraft, Israeli Prime Minister Eshkol may be looking for a firmer commitment to Israel's security. He must understand that security guarantees and treaties are out, but he may seek a guaranteed source of arms.”156 Still, he noted, “It's hard to know how much the Israelis are pushing the Soviet threat merely to justify their case for more arms.”157 Indeed, the Joint Chiefs of Staff assessed that the “Israeli Air Force can cope for the next 18 months with any potential threat they face.” Secretary of Defense Robert McNamara noted that “Israel can prevail over any potential Arab enemy” and expressed concern that acting on the plane request could invite “further Russian support” for the Arab states.158 Rusk asserted the need for Israel to court international opinion, particularly in the United Nations.159 Accordingly, Johnson pledged only “to keep Israel's military defense capability under active and sympathetic examination and review in the light of all relevant factors.”160 He thus delayed making a decision on the Phantoms.

The Johnson administration did not see an immediate Israeli need for the Phantoms, but it did envision that such a need could develop in the future given reports of increased Soviet involvement in the region.161 Despite mounting domestic political pressure in 1968 for the Johnson administration to approve Israel's aircraft requests, the president was unyielding. He argued with congressional leaders, “We don't want to be in a position of just being arms merchants and starting an arms race with the Russians there.”162 Soviet aircraft deliveries to Egypt and congressional pressure to maintain a U.S. commitment to Israel's security, however, led Johnson to reassess his earlier decision.163 The importance of domestic politics should not be overstated, however. As David Pollock writes, “[D]omestic political considerations had a greater effect on the timing than on the substance of [the Phantom decision].”164 Nevertheless, Johnson used the opportunity to extract Israeli promises to exercise “nuclear restraint.”165 Israel reaffirmed “that it will not be the first power in the Middle East to introduce nuclear weapons and agrees not to use any aircraft supplied by the United States as a nuclear weapons carrier.”166 This quid pro quo notwithstanding, the sale of offensive airplanes made the United States the main supplier of arms to Israel, reflecting a shift in U.S. leaders' assessments of Israel's ability to deter its enemies.

When Nixon became president in 1969, Egypt had already begun its so-called War of Attrition against Israel. Preoccupied with other major foreign policy issues, Nixon delegated the Arab-Israeli conflict to the State Department, which claimed that the United States should adopt an impartial policy toward the Middle East to curb growing Soviet influence. The rationale for refusing a defense pact remained, as one NSC paper averred, that “[w]e should avoid any open-ended and uncontrollable commitment [a security guarantee] because it would subordinate the United States to Israeli concepts of defense and security, and because it would polarize the area between us and the USSR…. Apart from a specific guarantee … we could give Israel a firm commitment to provide it the military equipment we believe needed to maintain a reasonable balance in the area.”167

Indeed, in 1969 Israel requested an additional 100 A-4 Skyhawks and 25 F-4 Phantoms, once again creating a dilemma for U.S. decisionmakers.168 After all, “the sale of sophisticated equipment [carried] the implied obligation to continue supply.”169 U.S. decisionmakers feared that a negative response would “not only risk a vehement political and propaganda reaction but could foster a go-it-alone psychology in Israel, encourage an even harder line toward the Arabs and diminish further our already limited influence there.” Nevertheless, “Any decision which added to Israel's already demonstrably superior military strength would produce seriously adverse reactions in the Arab world.” A positive decision would also provoke greater Soviet military involvement in the Middle East, but a negative decision could imply a “success for Soviet diplomacy.”170

Mindful of these considerations, the Nixon administration postponed its decision on the Phantoms, concluding that “detailed analysis has identified no military need for the additional aircraft Israel has requested for the time being. If as a result of actions by others, in particular the Soviet Union or France, or as a result of unusual losses, Israel's clear cut air superiority is threatened, we would be in a position to move quickly to maintain Israel's margin of safety.”171 This line of reasoning appeared in many memoranda and documents circulating among U.S. decisionmakers from December 1969 to March 1970. These reports reiterated the view that the local military balance of power continued to favor Israel, notwithstanding the Israeli government's insistence to the contrary.172 Indeed, calculations of the balance of power were directly linked to assessments about arms transfers. For example, one report stated: “Given the analysis of the present military balance above, it seems fair to conclude that the U.S. obligation to contribute to Israel's chances of survival could be fulfilled without any commitment right now to increase further Israel's aircraft inventory.” The authors of these reports also recognized the need to restrain Israel and warned that further arms sales would only embolden it and create risks for the United States to be dragged into the Arab-Israeli conflict. The “unqualified judgment” of all members of the NSC Working Group on the Middle East was that a decision to accept in full Israel's arms requests would “‘blow the place apart.’”173

During this time, U.S. decisionmakers began to see that a strong Israel could help manage the Soviet Union, now becoming a shared adversary of Israel and the United States. As Nixon bluntly asked, “Why should it not be our policy to let Israel scare them a little bit more?”174 Indeed, although the United States did not see Arab countries as adversaries the way Israel did, growing Soviet involvement in the Arab-Israeli conflict began to exert greater influence on U.S. diplomacy toward Israel.175 At one meeting, Nixon reasoned, “Assume for the sake of discussion that there is no domestic political pressure and that there is no moral question of continuing support involved, would the U.S. foreign policy interests be served by dumping Israel? … Looking at this from the Soviet viewpoint, if we save the UAR's [United Arab Republic's] bacon, the Soviets would gain by our act. In my view, Soviet-U.S. relations are the overriding concern. Therefore, the overriding question is: Who gains?”176 On another occasion, Nixon stated to Rabin: “I told you before to give it to them [the Egyptians and Russians] and to hit them as hard as you can. Every time I hear that you go at them, penetrate into their territory, I am delighted. As far as they are concerned, go ahead and hit them. The trouble is the rest of the Arabs. I very strongly believe that you are right, they are testing both you and us and we have to enable you to deter them.”177 Although U.S. and Israeli threat perceptions began to converge, the Nixon administration's desire to maintain positive relations with the Arab world and to preserve the balance of power prevented additional U.S. arms transfers.

Starting in April 1970, U.S. intelligence began to indicate that growing Soviet involvement in the region would soon shift the balance of power against Israel. As part of the War of Attrition, the Soviets had given surface-to-air missiles to Egypt, provided the Egyptians access to 10,000 Soviet advisers, and deployed Soviet combat pilots to fly over the Egyptian mainland. The United States had to rethink its initial reluctance to offer Israel arms. As Soviet involvement in the fighting deepened, Israel requested electronic countermeasures from the United States.178 Designed to neutralize Soviet surface-to-air missiles in Egypt, the electronic countermeasures would have provided “Israel the ability to mount deep raids against Soviet manned targets in Egypt.”179 Moreover, Israel sought unmanned aerial vehicles and RF-4Cs, which were Phantoms repurposed to engage in reconnaissance missions.180 The Nixon administration agreed to give Israel an anti-missile package and thus “compensate Israel for the military advantage gained by [Egypt] and Soviets [sic] as a result of the improvements in their dispositions west of the Suez Canal.”181 When Egypt violated a cease-fire agreement, Nixon promised Israel additional military equipment as a “riposte to ceasefire violations.”182 He expressed his keenness to “offset the military advantages gained by [Egypt].”183 Indeed, U.S. decisionmakers linked the necessity of giving these arms to the changing balance of power in the region. As Secretary of Defense William Rogers wrote to Nixon:

Your decision … to hold in abeyance Israel's request for additional aircraft was based on the judgment that Israel's qualitative superiority compensated amply for its numerical inferiority in planes. The direct Soviet involvement in an operational role has injected a new qualitative capacity and a reinforced quantitative capacity on the UAR side. In short, the intelligence evaluations indicate that the weight of the Soviet presence has already reduced the material and psychological advantages previously enjoyed by the Israelis. Fundamentally, the Arab-Israeli military balance now depends on Soviet actions and decisions which have already created a situation in which Israel's air superiority could be rapidly neutralized.184

Still, some U.S. decisionmakers criticized the provision of arms transfers to Israel. Secretary of Defense Melvin Laird, for example, argued that the United States should not provide Israel with a “deep penetration raid capability.”185 By contrast, Kissinger reasoned that providing offensive weapons of the sort described above would have a pacifying effect because “the provision of more security to Israel to enable her to cope with the Egyptians would be the factor most likely to deter Israeli thoughts of attack.”186 These disagreements notwithstanding, U.S. decisionmakers consistently drew on their assessments of the current and projected local balance of power to determine whether Israel had sufficient deterrent capabilities and, by extension, whether Israel required more arms.

Kissinger's memos to Nixon indicate that Kissinger believed that it was unproductive to restrict arms sales to Israel to pursue better relations with the Soviet Union and its clients.187 Concerned about direct Soviet involvement and impressed with Israel's performance during the Jordan crisis, in which Israel supported the United States and the Jordanian monarchy against the Palestine Liberation Organization, Kissinger told Nixon that Israel's interests were more compatible with U.S. interests than previously believed. Arguing that the State Department policy had “backfired,” Kissinger believed that Israel's military superiority should be restored with a supply of additional arms and reassurances.188 In a December 1970 memorandum written for Nixon, Kissinger noted “the progress the Soviet Union has recently made toward establishing hegemony in the [Middle East],” and observed that “the Soviets have … substantially increased their military presence in the region.”189 Based on Kissinger's assessment, Nixon approved an arms package to Israel worth $90 million. The transfer was costly in its scope, nature, and promise for more institutionalized arms transfers, comprising anti-tank weapons and reconnaissance aircraft, among other items. Still, Israel wanted more, including a guaranteed supply of high-performance aircraft (54 F-4As and 120 A-4s) and “long-term agreements that would prevent the periodic supply disruptions and quarrels that had marked the previous two years.”190 With Nasser's death in September 1970 and the ascendancy of Anwar el-Sadat to the Egyptian presidency, the Nixon administration sensed an opportunity to break the stalemate in the Arab-Israeli conflict. Yet Israel proved obstinate despite Sadat's overtures to the United States. Nixon lamented, “We cannot be in a position where we [continue to provide aid] and Israel says we won't talk…. That's what it gets down to.”191 At an NSC meeting, Nixon emphasized that “we will go all the way with Israel in maintaining the balance of power in its favor…. [The Israelis] assume that the U.S. will see them through regardless of what they do. This is not true.”192 In May 1971, Nixon wrote to Secretary of State Rogers that “it is essential that no more aid programs for Israel be approved until they agree to some kind of interim action on the Suez or some other issue.”193 Even when Sadat signed a new treaty with the Soviet Union that same month, Nixon and Rogers left U.S. policy unchanged, arguing that a defense pact with Israel would have “all sorts of problems.”194 Nixon withheld additional military aid transfers to Israel throughout much of 1971.195 This policy irked Kissinger, who argued that the military balance of power was tilting against Israel, and therefore it needed a steady flow of arms.196 In November 1971, the U.S. government conducted a major assessment of the balance of power in the Middle East. It noted that although Israel had maintained its qualitative advantage, two developments threatened Israel's position. First, “the shift in the balance that has taken place as a result of the Soviet-installed defense capability mainly affects Israel's pre-emptive strike capability … [which] is important to Israel because it deprives Israel of the ability to impose a short war.”197 The second development was the “continuing buildup in the USSR's own position in Egypt,” given that it “improve[d] Soviet capability against the U.S. and even, in an extreme situation, against Israel.”198 As Kissinger concluded, “Everyone here admits that Israel will need more planes over a 1–3 year span to continue normal modernization and upgrading of its air force. The main question is when those planes will be provided and in what political context.”199 In November 1971, Washington agreed to provide a new costly transfer of arms to Israel that would allow Israel to maintain its superiority for the years to come.200 The steady growth in U.S. military assistance to Israel continued over the next two years, during which opportunities to break the impasse between Israel and its Arab neighbors seemed possible. Sadat expelled Soviet military advisers from Egypt in 1972. Still, the Soviet Union continued to make large arms transfers to other Arab clients such as Syria.201 More importantly, the peace overtures that Sadat made toward Israel at this time went nowhere. Israel was not ready to surrender the Sinai Peninsula and, skeptical of the overtures, Kissinger dismissed Sadat's last major attempt for peace in February 1973 as “far-reaching but one-sided.”202 The following month, Israel made another major request for fighter jets. Nixon was initially ambivalent but soon supported Kissinger's position. Kissinger maintained that the military balance was tilting against Israel, adding that “only if the Arabs saw the Soviet arms did not hold the promise of a military solution would they turn to diplomacy in a serious way.”203 This policy developed despite Secretary of Defense Elliott Richardson's assertions that Israel still enjoyed a geostrategic advantage, thereby justifying a more evenhanded U.S. approach to the region.204 In the end, the Nixon administration made the promised Phantom and Skyhawk deliveries, fulfilling Israel's requirements for the next four years.205 Notwithstanding U.S. efforts to augment Israel's deterrent capabilities, Egypt and Syria coordinated a surprise attack on Israel in October 1973. This war sparked a fierce debate within the Nixon administration and the U.S. Congress over whether to supply Israel with significant military aid. But with heavy Israeli losses, mounting domestic pressure, a massive Soviet resupply effort, and Sadat's rejection of a cease-fire, this debate became moot. Nixon sought a congressional appropriation for a$2.2 billion airlift to help Israel prevail in the war.206 The 1973 war provided an opportunity for the United States to strengthen Arab relations, especially with Egypt, and take a leading role in postwar negotiations—a task made all the more urgent because of the Arab oil embargo. Still, Israel remained desperate for a long-term U.S. arms commitment, forcing Washington into a dilemma about how to reassure both sides.

### SUMMARY AND ALTERNATIVE ARGUMENTS REGARDING THE ISRAEL CASE

During the Kennedy, Johnson, and Nixon administrations, U.S. decisionmakers used two primary indicators to determine whether to offer Israel an alliance commitment or costly arms: the extent to which Israel and the United States had compatible security interests, and whether the current and projected military balance in the Middle East suggested that Israel could deter and defeat its adversaries. Because the United States never truly shared Israel's sense of threat, it was concerned that an alliance commitment would jeopardize its broader regional interests, particularly its desire for stronger ties with Arab states. U.S. assessments of Israel's relative military capabilities varied during this period. Much debate took place regarding Israel's projected military capabilities and its ability to maintain qualitative superiority over its Arab neighbors in the absence of costly arms transfers and in the presence of an increasingly assertive Soviet patron. Those who argued that Israel's military superiority could not be sustained without significant U.S. assistance, such as Kissinger, often suggested more costly transfers. Those who believed in Israel's ability to maintain superiority without significant assistance argued against continuous and unconditional support. The magnitude of U.S. arms transfers increased after 1968 in response to growing Soviet involvement in the region and the anticipated effect it would have on the balance of power in the region. The objective of U.S. assistance during the remainder of the 1970s was “to sustain Israeli military superiority,” according to a secret NSC memo.207

Critics may assert that domestic politics shaped U.S. commitments to Israel, yet the evidence in support of this alternative explanation is weak during the period we examine. The pattern of arms transfers during the Johnson administration represents a most-likely case for domestic political explanations. The Democratic Party captured most of the Jewish vote in the 1960s, and pro-Israel members of Congress pressed the administration to meet Israeli demands.208 Nevertheless, domestic pressures did not convince Johnson to offer Israel a formal defense pact, a nuclear security guarantee, or even a long-term arms commitment. Moreover, rarely did U.S. decisionmakers allude to U.S. domestic politics in their arms transfer reasoning. Some transactions—such as the Phantom delivery in 1968—do offer admittedly mixed evidence for our theory. Nevertheless, domestic factors should not be overstated. Johnson hesitated, and his delay reflected several strategic considerations: first, the Soviets were increasing their support to Egypt; and second, Israel offered an important concession to the United States by renewing its pledge not to introduce nuclear weapons into the region. During the Nixon years, notwithstanding high domestic support for Israel, U.S. policies still exhibited significant fluctuations. Moreover, throughout this period decisionmakers privately discussed geostrategic factors, specifically the evolving local military balance of power, in their deliberations over whether to transfer arms to Israel.209

We do not find significant evidence favoring other alternative arguments. The commercial logic for arms transfers is not supported by the documentary evidence, nor is the rationale that U.S. decisionmakers wished to recoup production costs by selling additional aircraft to Israel. Discussions involving the production line sometimes appear in the documentary record, but only because U.S. decisionmakers were unsure whether they could fulfill Israeli requests within a particular time frame. Occasionally, Israel's requests for advanced aircraft required U.S. inventory, thereby adversely affecting U.S. capabilities.

Finally, the documents reveal that U.S. decisionmakers often discussed using arms to obtain leverage with Israel.210 That these discussions took place does not validate this alternative argument because U.S. decisionmakers recognized the difficulties associated with using arms for such purposes. On the one hand, they feared that withholding aid would make Israel anxious and aggressive while emboldening the Soviet Union and its Middle Eastern clients. On the other hand, they worried that giving military aid to Israel would antagonize Arab countries and invite further Soviet involvement. Moreover, a failed effort to influence Israel's policies risked damaging the United States' regional reputation. U.S. decisionmakers wrestled with these issues with little resolution. (See figure 3 for a summary of our predictions and evidence.)

Figure 3.

Summary of Predictions and Evidence for Israel

Figure 3.

Summary of Predictions and Evidence for Israel

## Conclusion

This article has argued that great powers follow a clear strategic logic when deciding whether to ally with or give arms to client states. In contrast to previous studies, which claim that such decisions are shaped by domestic politics or commercial factors, we find that great powers signal reassurance while avoiding entrapment by offering their clients different bundles of security goods. Patrons assess the degree of shared threat and the local balances of capabilities in determining whether to support their clients with arms, alliance commitments, or both (see figure 4). This strategic logic helps to explain how great powers manage the “patron's dilemma.” A wealth of primary documents provides strong empirical support for our theory in the cases of U.S. security commitments to Taiwan and Israel.

Figure 4.

Summary of Argument

Figure 4.

Summary of Argument

Our argument suggests numerous avenues for future research. First, our findings could be tested by applying our theory to other patron-client relationships. Although our findings do not support the notion that domestic political considerations or commercial motivations guided U.S. commitment choices in the Taiwan and Israel cases, we readily acknowledge the potential influence of these factors. Future work could further theorize and test which types of foreign and security policies are most likely to be driven by domestic political or commercial logics rather than strategic considerations.211 Indeed, Roseanne McManus and Keren Yarhi-Milo show that while strategic concerns primarily influence which countries receive U.S. signals of support, the regime type of the recipient has great influence on whether the signal is sent in public, such as an alliance or formal presidential visits, or in private, such as with arms sales and military aid. This difference in signaling strategies toward democratic versus autocratic states can be attributed to concerns over domestic backlash.212

Second, further research could explore the strategic logic of a more comprehensive set of tools that patrons could use to manage security relations with their clients. We have shown that patrons use arms transfers and alliances to convey different forms of commitment. Yet it is possible that other tools should also be considered. Forward deployments of military assets, joint military exercises, and military basing are just some of the security tools that patrons could use as either complements or substitutes in supporting clients.

Third, future work should evaluate the preferences and perceptions of client states and adversaries regarding arms transfers and alliances. In this article, we focus exclusively on the patron's decisions, but what about those of the client or the client's adversary? How do clients interpret the receipt of these security goods? Do potential aggressors perceive arms-only partnerships as signaling a weaker commitment than formal alliances? These are important questions that require further theorizing and empirical testing.

Fourth, scholars should examine how patrons' provision of arms and alliances affects nuclear proliferation. Because Israel developed nuclear weapons and Taiwan had a nuclear program, it appears prima facie that conventional military arms did not eliminate their interest in nuclear weapons. Thus, in addition to delineating the range of policy tools at the disposal of patrons, researchers should examine their effects on extended deterrence.

Our research has important practical implications for U.S. policy toward allies and partners in Asia, Europe, and the Middle East. Many states are facing growing challenges as China becomes increasingly assertive, Russia coerces its neighbors, and Iran pursues nuclear capabilities. The United States and its allies and partners must consider how to mitigate these risks collectively. Our research sheds light on the dilemmas that U.S. decisionmakers are facing and the types of commitments that they are likely to provide different states. Consider East Asia, where China's rapid military modernization and increasingly assertive behavior will likely fuel the perception that the United States and many regional states have common security interests. We expect increased cooperation under existing alliances, such as those with Japan and the Philippines, and suggest that additional alignments are possible. For example, if domestic political opposition can be overcome, Vietnam could become a major security partner of the United States. With Vietnam in an unfavorable military position relative to China, arms transfers are possible, especially now that U.S. sales of lethal weapons to Vietnam are no longer banned. Accordingly, in June 2015, U.S. Secretary of Defense Ashton Carter announced a new “Southeast Asia Maritime Security Initiative” devoting $425 million to “capacity-building efforts” over the next five years.213 Assistant Secretary of Defense David Shear commented, “We're looking at maritime security shortfalls among our partners and we will be ready to discuss with them what it is they need and how they expect to use it.”214 If China's behavior continues to push the United States and Vietnam closer together, we suggest that it is even possible that an extended U.S. deterrent commitment could emerge. In short, facing an increasingly capable and assertive China, states in East Asia could receive increased arms transfers and, in some cases, expanded alliance commitments from the United States. Russian activities in Eastern Europe pose a somewhat different challenge. Ukraine is far weaker than Russia, so our theory suggests that the United States is likely to provide arms to Ukraine. Indeed, in 2015, U.S. Chairman of the Joint Chiefs of Staff Martin Dempsey recommended: “I think we should absolutely consider lethal aid and it ought to be in the context of NATO allies.”215 A group of former senior U.S. officials, including NATO military commanders and officials, agreed: “The West needs to bolster deterrence in Ukraine…. That requires providing direct military assistance—in far larger amounts than provided to date and including lethal defensive arms.”216 Accordingly, the United States has provided military assistance to Ukraine, although most of this support has been categorized as non-lethal given NATO's unwillingness to provide lethal arms. The lack of debate about incorporating Ukraine into NATO is also instructive. Our theory suggests that the withholding of NATO membership from Ukraine was the result of either the United States or Europe not viewing Russia as a common security concern. Indeed, in 2008, France and Germany blocked Ukraine's membership, despite U.S. support. Thus, the United States has pursued other options, including joint military exercises, greater consultations, and military assistance. Finally, in the Middle East, U.S. partners are facing a rare but not unprecedented situation. The United States shares concerns about Iran's nuclear program with Israel, Saudi Arabia, and the United Arab Emirates, among others. The 2015 negotiation and implementation of the Joint Comprehensive Plan of Action with Iran, however, might indicate a shift in U.S. perceptions about the commonality of security interests with Iran and, consequently, Iran's regional adversaries. If such a transformation continues, then it would make a defense pact between the United States and Israel or Saudi Arabia less likely. Still, it could lead the United States to provide Israel, Saudi Arabia, and others with even more defensive arms if U.S. policymakers assess that Iran's military capabilities are growing vis-à-vis its neighbors. ## Acknowledgments For their insights and suggestions, the authors thank Thomas Christensen, Timothy Crawford, Avery Goldstein, Joseph Grieco, Robert Jervis, Daniel Kurtzer, Benjamin Miller, Jeremy Pressman, the anonymous reviewers, and participants in international relations seminars at Columbia University and Lehigh University. ## Notes 1. Glenn H. Snyder, Alliance Politics (Ithaca, N.Y.: Cornell University Press, 1997). 2. U.S. Department of State, “Foreign Military Financing Account Summary” (Washington, D.C.: U.S. Department of State, 2015), http://www.state.gov/t/pm/ppa/sat/c14560.htm. 3. For domestic political explanations, see Galen Jackson, “The Showdown That Wasn't: U.S.-Israeli Relations and American Domestic Politics, 1973–75,” International Security, Vol. 39, No. 4 (Spring 2015), pp. 130–169. See also John J. Mearsheimer and Stephen M. Walt, The Israel Lobby and U.S. Foreign Policy (New York: Farrar, Straus and Giroux, 2008); Edward Tivnan, The Lobby: Jewish Political Power and American Foreign Policy (New York: Simon and Schuster, 1987); Robert H. Trice, Interest Groups and the Foreign Policy Process: U.S. Policy in the Middle East (Beverly Hills, Calif.: Sage, 1976); and Mitchell Geoffrey Bard, The Water's Edge and Beyond: Defining the Limits to Domestic Influence on United States Middle East Policy (New Brunswick, N.J.: Transaction, 1991). For explanations based on commercial motivations, see Lawrence Freedman, “British Foreign Policy to 1985, IV: Britain and the Arms Trade,” International Affairs, Vol. 54, No. 1 (July 1978), pp. 377–392. On a mixture of motives, see Edward A. Kolodziej, “France and the Arms Trade,” International Affairs, Vol. 56, No. 1 (January 1980), pp. 54–72. 4. On foreign policy substitution, see T. Clifton Morgan and Glenn Palmer, “A Model of Foreign Policy Substitutability: Selecting the Right Tools for the Job(s),” Journal of Conflict Resolution, Vol. 44, No. 1 (February 2000), pp. 11–32; and Benjamin A. Most and Harvey Starr, “International Relations Theory, Foreign Policy Substitutability, and ‘Nice’ Laws,” World Politics, Vol. 36, No. 3 (April 1984), pp. 383–406. 5. David A. Lake, Entangling Relations: American Foreign Policy in Its Century (Princeton, N.J.: Princeton University Press, 1999). 6. Matthew Fuhrmann and Todd S. Sechser, “Signaling Alliance Commitments: Hand-Tying and Sunk Costs in Extended Nuclear Deterrence,” American Journal of Political Science, Vol. 58, No. 4 (October 2014), pp. 919–935. 7. On alliances as a bundle of mixed security goods, see ibid. For alliances as written pledges, see James D. Morrow, “Alliances: Why Write Them Down?” Annual Review of Political Science, Vol. 3 (2000), pp. 63–83. 8. James D. Fearon, “Signaling Foreign Policy Interests: Tying Hands versus Sinking Costs,” Journal of Conflict Resolution, Vol. 41, No. 1 (February 1997), pp. 68–90. Some formal alliance commitments also feature extensive military cooperation and coordination. Many alliances include few signals of commitment beyond verbal promises. See Fuhrmann and Sechser, “Signaling Alliance Commitments.” 9. See Douglas M. Gibler, “The Costs of Reneging: Reputation and Alliance Formation,” Journal of Conflict Resolution, Vol. 52, No. 3 (June 2008), pp. 426–454; Mark J.C. Crescenzi et al., “Reliability, Reputation, and Alliance Formation,” International Studies Quarterly, Vol. 56, No. 2 (June 2012), pp. 259–274; and Gregory D. Miller, The Shadow of the Past: Reputation and Military Alliances before the First World War (Ithaca, N.Y.: Cornell University Press, 2012). 10. For a discussion of how the United States has prioritized the risk of being dragged into unwanted wars by its allies, see Michael Beckley, “The Myth of Entangling Alliances: Reassessing the Security Risks of U.S. Defense Pacts,” International Security, Vol. 39, No. 4 (Spring 2015), pp. 7–48. 11. Tongfi Kim, “Why Alliances Entangle but Seldom Entrap States,” Security Studies, Vol. 20, No. 3 (July 2011), pp. 350–377 (emphasis in the original). 12. Beckley, “The Myth of Entangling Alliances.” 13. Brett V. Benson, Constructing International Security: Alliances, Deterrence, and Moral Hazard (Cambridge: Cambridge University Press, 2012), pp. 99–100. 14. Snyder, Alliance Politics. 15. If the arms transfer comprises advanced weapons, then the patron might have to bear not only a budgetary burden but also some risk of undesirable technological transfer to the client. Such technological spillover could make the client less dependent on the patron for arms in the future, thereby depriving the patron of leverage. 16. See U.S. Department of State, “Foreign Military Financing Account Summary.” Arms transfers may be a substitute for crisis intervention should hostilities between the client and the adversary break out. Yet it remains unclear how the patron can remain neutral and not be dragged into an undesirable conflict. 17. Some offensive weapons are indistinguishable from defensive ones. In such cases, the signaling logic of arms transfers might be less pronounced compared with cases where unambiguously offensive weapons are supplied. 18. Sophistication might be another criterion. The more technologically sophisticated the weapon—operationalized by measuring the time passed since its initial fielding—the stronger the signal. Newer weapons are often qualitatively superior and may embolden the client. We omit this category because newer weapons are often more expensive and thus costly. 19. Arms transfers sometimes create reputation costs. An illustrative example is the alleged use by insurgents in eastern Ukraine of Russian anti-aircraft missiles against flight MH17. This accident hurt Russia's reputation and led to economic sanctions. Suspending arms transfers during a crisis could also create reputation costs. For example, the United States risks appearing unreliable if it suspends military aid to Israel during a conflict. 20. See Defense Security Cooperation Agency, “Foreign Military Financing” (Washington, D.C.: Defense Security Cooperation Agency, n.d.), http://www.dsca.mil/programs/foreign-militaryfinancing-fmf; and Defense Security Cooperation Agency, “Foreign Military Sales” (Washington, D.C.: Defense Security Cooperation Agency, n.d.), http://www.dsca.mil/programs/foreignmilitary-financing-fms. 21. Stephen M. Walt, The Origins of Alliances (Ithaca, N.Y.: Cornell University Press, 1987). 22. Relatively strong patrons can also better deter adversaries from attacking their allies. See Paul K. Huth, “Extended Deterrence and the Outbreak of War,” American Political Science Review, Vol. 82, No. 2 (June 1988), pp. 423–443. 23. Of course, major powers have more interests than their weaker allies, but they can still prioritize threats similarly. 24. Benson, Constructing International Security. 25. To be exhaustive, consider a situation of zero compatibility. The patron could offer at best a weak commitment to the potential client in return for something that the patron values. Yet such commitments should be empirically rare. Our theory cannot explain such alliances given its emphasis on shared threat assessments. 26. Scott L. Kastner, “Is the Taiwan Strait Still a Flash Point? Rethinking the Prospects for Armed Conflict between China and Taiwan,” International Security, Vol. 40, No. 3 (Winter 2015/16), pp. 54–92. 27. Admittedly, clients might have domestic reasons that could, for instance, lead them to prefer arms to a formal alliance. For example, Roseanne W. McManus and Keren Yarhi-Milo show that the United States is less likely to provide highly public signals of support to its more autocratic clients because of fears of domestic backlash in both the United States and the client country. See McManus and Yarhi-Milo, “The Logic of ‘Backstage’ Signaling: Domestic Politics, Regime Type, and Major Power–Protégé Relations,” Baruch College, CUNY, and Princeton University, 2016. 28. James D. Morrow, “Alliances, Credibility, and Peacetime Costs,” Journal of Conflict Resolution, Vol. 38, No. 2 (June 1994), pp. 270–297. 29. The patron might still choose to supply some arms occasionally to maintain the client's deterrent capability, ensure interoperability should deterrence fail, and allow time to come to the client's defense. We do not expect the provision of costly arms in this scenario, so institutionalized provisions of a large amount of offensive weapons are unlikely. 30. Glenn H. Snyder, “The Security Dilemma in Alliance Politics,” World Politics, Vol. 36, No. 4 (July 1984), p. 471. 31. The patron could also attach end-use agreements to provisions of arms so as to clarify that it would not tolerate their use against a particular target state. Clients can, however, violate such agreements during crises. Verifying any violations could also be difficult. 32. Timothy W. Crawford, Pivotal Deterrence: Third-Party Statecraft and the Pursuit of Peace (Ithaca, N.Y.: Cornell University Press, 2003). 33. Some security ties between the patron and client could continue under these circumstances. For example, a client may desire to decrease its defense spending by relying increasingly on external support. A patron may also wish to lessen its requirements for global military deployments by seeking to increase its client's defensive capabilities. Thus, although we predict that new alliances and major arms sales will be unlikely, they might still occur in highly conditional or limited forms that would minimize moral hazard. 34. Alexander L. George and Andrew Bennett, Case Studies and Theory Development in the Social Sciences (Cambridge, Mass.: MIT Press, 2004). 35. Consistent with U.S. government records, we refer to the People's Republic of China as “China” and the Republic of China as “Taiwan.” 36. Stephen M. Goldstein, “Dialogue of the Deaf? The Sino-American Ambassadorial-Level Talks, 1955–1970,” in Robert S. Ross and Changbin Jiang, eds., Reexamining the Cold War: U.S.-China Diplomacy, 1954–1973 (Cambridge, Mass.: Harvard University Press, 2002), p. 201. 37. Gordon H. Chang and He Di, “The Absence of War in the U.S.-China Confrontation over Quemoy and Matsu in 1954–1955: Contingency, Luck, Deterrence,” American Historical Review, Vol. 98, No. 5 (December 1981), p. 1508. 38. See Hongshan Li and Zhaohui Hong, eds., Image, Perception, and the Making of U.S.-China Relations (Lanham, Md.: University Press of America, 1998), p. 351. 39. Mutual Defense Treaty between the United States and Taiwan, March 3, 1955, TIAS 3178; 6 UST 433–438, http://www.taiwandocuments.org/mutual01.htm. 40. Thomas J. Christensen, Worse Than a Monolith: Alliance Politics and Problems of Coercive Diplomacy in Asia (Princeton, N.J.: Princeton University Press, 2011), p. 239. 41. Ibid., p. 143. On U.S. fears of entrapment, see ibid., pp. 142–143. 42. Steven M. Goldstein, “The United States and the Republic of China, 1949–1978: Suspicious Allies” (Stanford, Calif.: Institute for International Studies, 2000), pp. 7–9. 43. Gordon H. Chang, “To the Nuclear Brink: Eisenhower, Dulles, and the Quemoy-Matsu Crisis,” International Security, Vol. 12, No. 4 (Spring 1988), p. 104. 44. Matthew Jones, After Hiroshima: The United States, Race, and Nuclear Weapons in Asia, 1945–1965 (Cambridge: Cambridge University Press, 2010), pp. 251–252. 45. Memorandum of a Conversation, March 16, 1956, 9:30 P.M., Foreign Relations of the United States (FRUS) 1955–1957, Vol. 3: China (Washington, D.C.: Government Printing Office [GPO], 1986), p. 329. 46. Assistant Secretary for East Asia Walter Robertson also warned that the Soviet Union, “though great and dangerous, is not as active as the Chinese Communist menace to Asia.” See Nancy Bernkopf Tucker, The China Threat: Memories, Myths, and Realities in the 1950s (New York: Columbia University Press, 2012), p. 176. 47. Robert Accinelli, “A Thorn in the Side of Peace: The Eisenhower Administration and the 1958 Offshore Islands Crisis,” in Ross and Jiang, Reexamining the Cold War, p. 109. 48. National Security Council Report, January 15, 1955, FRUS 1955–1957, Vol. 2: China (Washington, D.C.: GPO, 1986), pp. 30–34. 49. On what these weapons signaled, see Tucker, The China Threat, p. 141. 50. Nancy Bernkopf Tucker, Strait Talk: United States–Taiwan Relations and the Crisis with China (Cambridge, Mass.: Harvard University Press, 2009), pp. 14–15. 51. Special National Intelligence Estimate, April 9, 1957, FRUS 1955–1957, Vol. 3, pp. 515–518. 52. Jones, After Hiroshima, p. 380. 53. Tucker, The China Threat, p. 145. 54. Memorandum from the Executive Secretary of the National Security Council (Lay) to the National Security Council, September 9, 1957, FRUS 1955–1957, Vol. 3, p. 595. 55. Memorandum of Discussion at the 338th Meeting of the National Security Council, October 2, 1957, FRUS 1955–1957, Vol. 3, p. 615. 56. U.S. decisionmakers recognized that Taiwan could not launch military operations beyond irritating but minor incursions: “[W]e know of no [Taiwanese] plans to mount any large-scale military or paramilitary operations now or in the near future, such operations are unlikely and beyond Taiwanese capabilities.” See National Intelligence Estimate, August 27, 1957, FRUS 1955–1957, Vol. 3, p. 591. The remote possibility of an attack on the Chinese mainland was nevertheless discussed. See Telegram from the Chief of the Military Assistance Advisory Group, Formosa (Smythe) to the Commander in Chief, Pacific (Stump), September 18, 1955, 1:30 P.M., FRUS 1955–1957, Vol. 3, pp. 91–92. 57. Telegram from the Embassy in the Republic of China to the Department of State, July 27, 1962, 6 p.m., FRUS 1961–1963, Vol. 22: Northeast Asia (Washington, D.C.: GPO, 1996), pp. 294–295. 58. Message from the Assistant Secretary of State for Far Eastern Affairs (Harriman) to the Ambassador to the Republic of China (Kirk), August 8, 1962, FRUS 1961–1963, Vol. 22, pp. 301–302. 59. Goldstein, “The United States and the Republic of China, 1949–1978,” p. 14. See also Memorandum from the President's Assistant for National Security Affairs (Kissinger) to President Nixon, December 9, 1969, FRUS 1969–1976, Vol. 17: China, 1969–1972 (Washington, D.C.: GPO, 2006), p. 144. 60. See, for example, Memorandum of Discussion at the 338th Meeting of the National Security Council, pp. 611–619. 61. See Memorandum for the Record, March 31, 1962, FRUS 1961–1963, Vol. 22, pp. 204–205; and Telegram from the Embassy in Poland to the Department of State, September 11, 1963, 7 p.m., FRUS 1961–1963, Vol. 22, pp. 392–395. 62. National Policy Paper, September 11, 1964, FRUS 1964–1968, Vol. 30: China (Washington, D.C.: GPO, 1998), p. 88. 63. Robert S. Ross, “Introduction,” in Ross and Jiang, Reexamining the Cold War, p. 12. 64. William Burr and Jeffrey T. Richelson, “Whether to ‘Strangle the Baby in the Cradle’: The United States and the Chinese Nuclear Program, 1960–64,” International Security, Vol. 25, No. 3 (Winter 2000/01), pp. 54–99. 65. U.S. leaders were apparently not aware that Chinese leaders had scaled back their ambitions by the late 1950s. See “Discussion between N.S. Khrushchev and Mao Zedong,” October 2, 1959, Wilson Center Digital Archive, http://digitalarchive.wilsoncenter.org/document/112088. 66. Telegram from the Department of State to the Embassy in the Republic of China, February 13, 1968, 0250Z, FRUS 1964–1968, Vol. 30, p. 638. 67. Ross, “Introduction,” p. 12; Hal Brands, “Rethinking Nonproliferation: LBJ, the Gilpatric Committee, and U.S. National Security Policy,” Journal of Cold War Studies, Vol. 8, No. 2 (Spring 2006), pp. 83–113; and Fredrik Logevall, Choosing War: The Lost Chance for Peace and the Escalation of War in Vietnam (Berkeley: University of California Press, 1999). 68. Telegram from the Department of State to the Embassy in the Republic of China, March 16, 1967, 3:43 p.m., FRUS 1964–1968, Vol. 30, p. 539. 69. Memorandum of Conversation, May 9, 1967, 12–12:55 p.m., FRUS 1964–1968, Vol. 30, pp. 556–561. See also Jay Taylor, The Generalissimo: Chiang Kai-shek and the Struggle for Modern China (Cambridge, Mass.: Harvard University Press, 2009), p. 532. 70. National Security Decision Memorandum 17, June 26, 1969, FRUS 1969–1976, Vol. 17, p. 40. 71. “China” (Washington, D.C.: Nuclear Threat Initiative, April 2015), http://www.nti.org/country-profiles/china/. 72. “China's Military Policy and General Purpose Forces,” National Intelligence Estimate, July 20, 1972, NIE 13-3-72, National Security Agency Electronic Briefing Book 372, doc. 6, http://nsarchive.gwu.edu/NSAEBB/NSAEBB372/docs/Underground-China72.pdf, p. 4. 73. Response to National Security Study Memorandum 124, May 27, 1971, FRUS 1969–1976, Vol. 17, pp. 330–331. 74. Study Prepared by the Ad Hoc Interdepartmental Regional Group for East Asia and the Pacific, November 12, 1974, FRUS 1969–1976, Vol. 18: China, 1973–1976 (Washington, D.C.: GPO, 2007), pp. 545–558. 75. Ibid. 76. Memorandum from the President's Assistant for National Security Affairs (Kissinger) to President Nixon, November 19, 1973, FRUS 1969–1976, Vol. 18, p. 433. 77. Memorandum of Conversation, February 21, 1973, 6 p.m., FRUS 1969–1976, Vol. 18, p. 198. 78. Editorial Note, FRUS 1969–1976, Vol. 17, pp. 636–637. 79. Ibid. 80. Jing Huang and Xiaoting Li, Inseparable Separation: The Making of China's Taiwan Policy (Singapore: World Scientific, 2010), p. 76. 81. The Taiwan Strait Patrol was a group of U.S. Navy vessels based in Keeling, Taiwan, that patrolled the waters near China's Fujian province. See Bruce A. Elleman, High Seas Buffer: The Taiwan Patrol Force, 1950–1979 (Newport, R.I.: Naval War College, 2012). Quotes from Alan D. Romberg, Rein In at the Brink of the Precipice: American Policy toward Taiwan and U.S.-PRC Relations (Washington, D.C.: Henry L. Stimson Center, 2003), pp. 26–27. 82. Study Prepared by the Ad Hoc Interdepartmental Regional Group for East Asia and the Pacific, pp. 548–549. 83. Ibid., p. 552. 84. Ibid., p. 554. 85. Memorandum from Secretary of State Vance to President Carter, July 24, 1977, FRUS 1977–1980, Vol. 13: China (Washington, D.C.: GPO, 2013), pp. 115–116. 86. On normalization, see William C. Kirby, Robert S. Ross, and Gong Li, eds., Normalization of U.S.-China Relations: An International History (Cambridge, Mass.: Harvard University Press, 2007). 87. National Intelligence Analytical Memorandum, July 26, 1977, FRUS 1977–1980, Vol. 13, pp. 116–118. 88. National Intelligence Estimate: PRC Defense Policy and Armed Forces, November 11, 1976, NIE 13-76, Central Intelligence Agency Freedom of Information Act Electronic Reading Room, pp. 65–68, https://www.cia.gov/library/readingroom/docs/DOC_0001097855.pdf. A later RAND report corroborates this view. See David A. Shlapak et al., “A Question of Balance: Political Context and Military Aspects of the China-Taiwan Dispute” (Santa Monica, Calif.: RAND Corporation, 2009), pp. 22–23. 89. To prevent Taiwan from undercutting U.S. policies, Brzezinski's adviser wrote that “we should link weapons sales to progress on normalization … to indicate to Taipei that they will bear some costs in the event momentum on normalization is lost.” Memorandum from Michel Oksenberg of the National Security Council Staff to the President's Assistant for National Security Affairs (Brzezinski), September 23, 1977, FRUS 1977–1980, Vol. 13, pp. 231–238. 90. Memorandum from Michel Oksenberg of the National Security Council Staff to the President's Assistant for National Security Affairs (Brzezinski), March 1, 1978, FRUS 1977–1980, Vol. 13, pp. 295–297. 91. Memorandum from Secretary of State Vance to President Carter, April 15, 1977, FRUS 1977–1980, Vol. 13, p. 77. 92. Ibid. 93. Memorandum from the President's Assistant for National Security Affairs (Brzezinski) to President Carter, June 14, 1977, FRUS 1977–1980, Vol. 13, pp. 94–95. 94. Memorandum from Secretary of State Vance to President Carter, April 15, 1977, p. 82 n. 5. 95. Memorandum of Conversation, July 30, 1977, 9:30–11:15 A.M., FRUS 1977–1980, Vol. 13, pp. 130–132; and Romberg, Rein In at the Brink of the Precipice, pp. 88–89. 96. Backchannel Message from Secretary of State Vance and the President's Assistant for National Security Affairs (Brzezinski) to the Ambassador to the Republic of China (Unger), December 15, 1978, 1518Z, FRUS 1977–1980, Vol. 13, p. 650. 97. Ibid., p. 651. 98. National Intelligence Analytical Memorandum, July 26, 1977. 99. Memorandum from Michel Oksenberg of the National Security Council Staff to the President's Assistant for National Security Affairs (Brzezinski), August 21, 1978, FRUS 1977–1980, Vol. 13, p. 518. 100. Memorandum from the President's Assistant for National Security Affairs (Brzezinski) to President Carter, October 26, 1978, with attachment Memorandum from Acting Secretary of State Newsom to President Carter, October 20, 1978, FRUS 1977–1980, Vol. 13, pp. 577–581. 101. Paper Prepared by the National Security Council Staff, n.d., FRUS 1977–1980, Vol. 13, p. 305. 102. Memorandum from the President's Assistant for National Security Affairs (Brzezinski) to President Carter, October 26, 1978, with attachment Memorandum from Acting Secretary of State Newsom to President Carter, October 20, 1978, p. 578. 103. See Editorial Note, FRUS 1977–1980, Vol. 13, pp. 857–869. 104. Taiwan Relations Act, Public Law 96-8, U.S. Code 22 (1979), § 3301, http://www.ait.org.tw/en/taiwan-relations-act.html. 105. Ibid. 106. See ibid, section 3. 107. Romberg, Rein In at the Brink of the Precipice, pp. 108–110. 108. Memorandum of Conversation, May 3, 1979, 3:18–4:25 p.m., FRUS 1977–1980, Vol. 13, p. 872. 109. Memorandum from Secretary of State Vance to President Carter, December 19, 1979, FRUS 1977–1980, Vol. 13, p. 1022. 110. Ibid. 111. Memorandum from the Assistant Secretary of State for East Asian and Pacific Affairs (Holbrooke), the Deputy Assistant Secretary of Defense for East Asian and Pacific Affairs (Abramowitz), and Michael Armacost and Michel Oksenberg of the National Security Council Staff to Secretary of State Vance, Secretary of Defense Brown, and the President's Assistant for National Security Affairs (Brzezinski), April 4, 1978, FRUS 1977–1980, Vol. 13, p. 335. 112. See document NLC-133-995-3-7, Jimmy Carter Presidential Library (JCL), Atlanta, Georgia, p. 12. 113. Memorandum from Secretary of State Vance to President Carter, FRUS 1977–1980, Vol. 13, p. 1022. 114. The F-5Es were aging, short-range aircraft on which Taiwan was reliant. 115. “Joint Communique of the United States of America and the People's Republic of China,” August 17, 1982, http://www.taiwandocuments.org/communique03.htm. 116. James Lilley with Jeffrey Lilley, China Hands: Nine Decades of Adventure, Espionage, and Diplomacy in Asia (New York: PublicAffairs, 2004), p. 247. 117. Ibid., p. 139. 118. Ibid., p.248. 119. Ibid. Reagan also wrote a secret memo stating that any willingness to reduce arms transfers to Taiwan (as implied by the 1982 communiqué) should be conditioned on China's commitment to the peaceful resolution of those countries' differences. See Tucker, Strait Talk, p. 152. 120. Memorandum from the Vice President's Chief of Staff (Moe) to Vice President Mondale, the President's Assistant (Jordan), the President's Assistant for National Security Affairs (Brzezinski), and the President's Deputy Assistant for National Security Affairs (Aaron), May 15, 1978, FRUS 1977–1980, Vol. 13, p. 376. 121. Memorandum from the President's Assistant for National Security Affairs (Brzezinski) to President Carter, July 29, 1977, FRUS 1977–1980, Vol. 13, p. 122. 122. Ibid. 123. Abraham Ben-Zvi, Decade of Transition: Eisenhower, Kennedy, and the Origin of the American-Israeli Alliance (New York: Columbia University Press, 1998), p. 69. 124. Memorandum from the Department of State Executive Secretary (Brubeck) to the President's Special Assistant for National Security Affairs (Bundy), May 14, 1963, FRUS 1961–1963, Vol. 18: Near East, 1962–1963 (Washington, D.C.: GPO, 1995), pp. 528–529. Israel subsequently pressured U.S. leaders to receive such assurances. See Memorandum for the Record, May 14, 1963, FRUS 1961–1963, Vol. 18, pp. 535–538. 125. John F. Kennedy, press conference, May 8, 1963, Public Papers of the Presidents of the United States: John F. Kennedy, Vol. 3: 1963 (Washington, D.C.: GPO, 1964), p. 373. 126. Letter from the Assistant Secretary of State for Near Eastern and South Asian Affairs (Talbot) to the Ambassador to the United Arab Republic (Badeau), May 20, 1963, FRUS 1961–1963, Vol. 18, p. 545. 127. Telegram from the Department of State to the Embassy in Israel, October 2, 1963, 6:26 p.m., FRUS 1961–1963, Vol. 18, p. 721. 128. Letter from the Deputy Assistant Secretary of Defense for International Security Affairs (Sloan) to the Deputy Assistant Secretary of State for Near Eastern and South Asian Affairs (Grant), August 22, 1963, FRUS 1961–1963, Vol. 18, p. 684. 129. As one internal State Department memorandum reported, “New United States arrangements with Israel could result in comparable Soviet-Arab ties, bringing the Soviets back in, probably in a more permanent and damaging fashion.” Quoted in Jeremy Pressman, Warring Friends: Alliance Restraint in International Politics (Ithaca, N.Y.: Cornell University Press, 2008), p. 90. 130. See Memorandum from the Department of State Executive Secretary (Read) to the President's Special Assistant for National Security Affairs (Bundy), September 6, 1963, FRUS 1961–1963, Vol. 18, doc. 321. 131. Telegram from the Department of State to the Embassy in Israel. 132. Telegram from the Department of State to the Embassy in the United Arab Republic, May 27, 1963, 2:54 P.M., FRUS 1961–1963, Vol. 18, pp. 556–557. Kennedy was also concerned that Egypt might be contemplating a preventive war against Israel's nuclear program, and that a defense pact with Israel might entrap the United States. See Memorandum of Conversation, July 23, 1963, 4:30 p.m., FRUS 1961–1963, Vol. 18, p. 659. 133. Letter from the Deputy Assistant Secretary of Defense (Bundy) to the Deputy Assistant Secretary of State for Near Eastern and South Asian Affairs (Grant), July 16, 1962, FRUS 1961–1963, Vol. 18, pp. 8–9. 134. Memorandum from Robert W. Komer of the National Security Council Staff to President Kennedy, July 23, 1963, FRUS 1961–1963, Vol. 18, p. 652. The documents are ambiguous as to whether Kennedy linked the Hawk sale to an Israeli renunciation of nuclear weapons or an initiative to resolve the Palestinian refugee problem. For conflicting accounts, see Douglas Little, “The Making of a Special Relationship: The United States and Israel, 1957–68,” International Journal of Middle East Studies, Vol. 25, No. 4 (November 1993), pp. 568–569; and Ben-Zvi, Decade of Transition. 135. Steven L. Spiegel, The Other Arab-Israeli Conflict: Making America's Middle East Policy from Truman to Reagan (Chicago: University of Chicago Press, 1985), p. 108. 136. National Security Estimate, January 23, 1963, FRUS 1961–1963, Vol. 18, doc. 139. 137. Memorandum for Record, January 10, 1964, FRUS 1964–1968, Vol. 18, pp. 11–12. Bundy later notified the Israeli government that the tank order would cost about 7.5 percent of its total budget. See Memorandum from the President's Special Assistant for National Security Affairs (Bundy) to President Johnson, March 13, 1964, FRUS 1964–1968, Vol. 18, p. 71. 138. Memorandum from the Joint Chiefs of Staff to Secretary of Defense McNamara, January 18, 1964, FRUS 1964–1968, Vol. 18, p. 25. 139. Memorandum from Robert W. Komer of the National Security Council Staff to President Johnson, February 26, 1964, FRUS 1964–1968, Vol. 18, p. 43. 140. See Memorandum from Secretary of State Rusk to President Johnson, January 16, 1964, FRUS 1964–1968, Vol. 18, p. 17. 141. Memorandum from the Joint Chiefs of Staff to Secretary of Defense McNamara, January 18, 1964, p. 24. 142. Memorandum from the Joint Chiefs of Staff to Secretary of Defense McNamara, March 12, 1964, FRUS 1964–1968, Vol. 18, p. 67. 143. Telegram from the Embassy in Israel to the Department of State, April 7, 1964, 12:30 p.m., FRUS 1964–1968, Vol. 18, pp. 84–85. 144. Ibid. 145. Memorandum of Conversation, May 17, 1964, FRUS 1964–1968, Vol. 18, p. 131. 146. Memorandum for the Record, April 30, 1964, FRUS 1964–1968, Vol. 18, pp. 113–114. 147. Ibid., p. 113. Third-party supplying of tanks to Israel would prove unreliable. Pressure on the United States to supply tanks directly to Israel subsequently mounted when the United States was negotiating an arms transfer to Jordan, a state that Israel saw as hostile. To make this transfer palatable to Israel, the United States placed conditions on its sale of tanks to Jordan. Also, it agreed to provide Israel with tanks and, should no other supplier be forthcoming, small numbers of fighter jets. Memorandum from the President's Deputy Special Assistant for National Security Affairs (Komer) to President Johnson, February 22, 1966, 6 p.m., FRUS 1964–1968, Vol. 18, pp. 556–557; and Memorandum from Robert W. Komer of the National Security Council Staff to President Johnson, June 16, 1965, 9:30 P.M., FRUS 1964–1968, Vol. 18, pp. 473–474. 148. Memorandum from Acting Secretary of State Katzenbach to President Johnson, December 11, 1967, FRUS 1964–1968, Vol. 20: Arab-Israeli Dispute, 1967–68 (Washington, D.C.: GPO, 2001), p. 29. 149. Memorandum from the President's Special Assistant (Rostow) to President Johnson, December 15, 1967, FRUS 1964–1968, Vol. 20, p. 39. See also Memorandum of Conversation, January 8, 1968, Session 2, FRUS 1964–1968, Vol. 20, pp. 88, 92. 150. “The U.S.-Israeli Military Relationship,” undated, JCL. 151. National Intelligence Estimate, March 5, 1970, FRUS 1969–1976, Vol. 12: Soviet Union, January 1969–October 1970 (Washington, D.C.: GPO, 2006), p. 415. 152. Memorandum of Conversation, February 7, 1968, FRUS 1964–1968, Vol. 20, p. 150. 153. These statements suggest that U.S. decisionmakers saw Israel as security-seeking rather than revisionist. See Memorandum from Secretary of State Rusk to President Johnson, May 23, 1968, FRUS 1964–1968, Vol. 20, p. 356. 154. Telegram from the President's Special Assistant (Rostow) to President Johnson in Texas, January 6, 1968, 2333Z, FRUS 1964–1968, Vol. 20, pp. 71–73. 155. Memorandum from Secretary of Defense McNamara to President Johnson, February 6, 1968, FRUS 1964–1968, Vol. 20, p. 141. 156. Telegram from the President's Special Assistant (Rostow) to President Johnson in Texas, January 6, 1968, 1639Z, FRUS 1964–1968, Vol. 20, p. 70. 157. Ibid., p. 71. 158. Both quotes from Memorandum of Conversation, January 8, 1968, p. 92. 159. Ibid., p. 94. 160. David Pollock, The Politics of Pressure: American Arms and Israeli Policy since the Six Day War (Westport, Conn.: Greenwood, 1982), p. 34. 161. Telegram from Rostow to President Johnson, FRUS 1964–1968, Vol. 20, pp. 75–79; and Memorandum of Conversation, FRUS 1964–1968, Vol. 20, pp. 96–97. 162. Notes on President Johnson's Meeting with Congressional Leaders, FRUS 1964–1968, Vol. 20, p. 487. 163. Telegram from Department of State to Selected Posts, FRUS 1964–1968, Vol. 20, pp. 548–550. 164. Pollock, The Politics of Pressure, p. 38. 165. Ibid, pp. 584–585. Because Israel chose not to clarify its nuclear weapons capability, it still depended largely on conventional military power to deter adversaries. Indeed, Israel's nuclear weapons were useless against the sort of aggression that characterized the War of Attrition. The frequent allusions to Israel's conventional military power in the documentary record demonstrate that U.S. decisionmakers understood this aspect of Israel's strategic situation. 166. Letter from the Assistant Secretary of Defense for International Security Affairs (Warnke) to the Israeli Ambassador (Rabin), November 27, 1968, FRUS 1964–1968, Vol. 20, pp. 661–662. 167. Paper Prepared by the Interdepartmental Group for Near East and South Asia, February 20, 1969, FRUS 1969–1976, Vol. 23: Arab-Israeli Dispute, 1969–1972 (Washington, D.C.: GPO, 2015), p. 33. 168. Memorandum from Richard Helms for Nixon, September 24, 1969, folder “Israel Vol. II: June 1, 1969 to Sep 20, 1969,” box 605, NSC Files, Country Files, Richard M. Nixon Library (RMNL); and The Situation in the Middle East—Summary, September 24, 1969, folder “Israel Vol. II: June 1, 1969 to Sep 20, 1969,” box 605, NSC Files, Country Files, RMNL. 169. Memorandum from the President's Assistant for National Security Affairs (Kissinger) to President Nixon, August 28, 1969, FRUS 1969–1976, Vol. 23, p. 156. 170. “Responses to Israel's Arms and Economic Assistance Requests,” undated, RMNL. See also Memorandum from the President's Assistant for National Security Affairs (Kissinger) to President Nixon, September 10, 1969, FRUS 1969–76, Vol. 23, pp. 159, 161. 171. Department of State Telegram 29464, folder “Israel Vol. IV: 01 Mar 70 to 21 May 70,” box 606, Country Files, NSC Files, RMNL. 172. Memorandum to Henry A. Kissinger from Ambassador Charles W. Yost, May 18, 1970, folder “Israel Vol. IV: 01 Mar 70 to 21 May 70,” box 606, Country Files, NSC Files, RMNL; “The US Response to Israel's Aircraft Needs—An Assessment,” March 26, 1970, folder “Israel Vol. IV: 01 Mar 70 to 21 May 70,” box 606, Country Files, NSC Files, RMNL; and Memorandum for the Assistant to the President for National Security Affairs, April 6, 1970, folder “Israel Vol. IV: 01 Mar 70 to 21 May 70,” box 606, Country Files, NSC Files, RMNL. 173. Memorandum by David E. Mark (INR), undated, folder “Israel Vol. IV: 01 Mar 70 to 21 May 70,” box 606, Country Files, NSC Files, RMNL; and Memorandum for Dr. Kissinger from Harold H. Saunders, March 16, 1970, folder “Israel Vol. IV: Mar 70 70–21 May 70,” box 606, Country Files, NSC Files, RMNL. 174. Minutes of a National Security Council Meeting, December 10, 1969, 10 a.m., FRUS 1969–1976, Vol. 23, p. 246. 175. Editorial Note, FRUS 1969–1976, Vol. 23, p. 393. 176. Minutes of a National Security Council Meeting, December 10, 1969, 10 a.m., p. 254. The UAR was a political union between Egypt and Syria that lasted from 1958 to 1961. 177. Editorial Note, FRUS 1969–1976, Vol. 23, p. 393. 178. Memorandum for the Secretary of Defense, July 4, 1970, folder “Israel Vol. V [1 of 3]: 22 May 70–Jul 70,” box 607, Country Files, NSC Files, RMNL; and Memorandum for the Secretary of Defense, July 4, 1970, folder “Israel Vol. V [1 of 3]: 22 May 70–Jul 70,” box 607, Country Files, NSC Files, RMNL. 179. Ibid. 180. Memorandum of Conversation, July 29, 1970, folder “Israel Vol. V [1 of 3]: 22 May 70–Jul 70,” box 607, Country Files, NSC Files, RMNL. 181. Memorandum for the President, undated, folder “Israel August 1, 1970–September 30, 1970,” box 607, Country Files, NSC Files, RMNL. 182. Memorandum for Dr. Kissinger, September 12, 1970, folder “Israel August 1, 1970–September 30, 1970,” box 607, Country Files, NSC Files, RMNL. 183. Memorandum from President Nixon to Secretary of State Rogers and Secretary of Defense Laird, September 23, 1970, FRUS 1969–1976, Vol. 23, p. 552. 184. Memorandum from Secretary of State Rogers to President Nixon, June 9, 1970, FRUS 1969–1976, Vol. 23, p. 416. 185. Memorandum for the Assistant to the President for National Security Affairs, August 29, 1970, folder “Israel August 1, 1970–September 30, 1970,” box 607, Country Files, NSC Files, RMNL. 186. Memorandum for the President, September 29, 1970, folder “Israel August 1, 1970–September 30, 1970,” box 607, Country Files, NSC Files, RMNL. 187. Memorandum of Conversation, March 12, 1970, 11:15 a.m., FRUS 1969–1976, Vol. 23, pp. 330–331. For policy papers on how to handle these developments, see Paper Prepared by the National Security Council Staff, May 7, 1970, FRUS 1969–1976, Vol. 23, pp. 370–376; and Paper Prepared by the National Security Council Staff, May 20, 1970, FRUS 1969–1976, Vol. 23, pp. 383–386. 188. Kissinger and the State Department vehemently disagreed on U.S. policy toward Israel. See David A. Korn, “U.S.-Soviet Negotiations of 1969 and the Rogers Plan,” Middle East Journal, Vol. 44, No. 1 (Winter 1990), p. 43. 189. Memorandum for the President from Kissinger, December 1970, folder “Israel December 1–January 30, 1970,” box 608, Country Files, NSC Files, RMNL. 190. William B. Quandt, Peace Process: American Diplomacy and the Arab-Israeli Conflict since 1967, 3rd ed. (Berkeley: University of California Press, 2005), p. 97. Pollock claims that the White House was decoupling military transfers from concessions. See Pollock Politics, pp. 121, 128–129. 191. Nixon quoted in Craig A. Daigle, “The Russians Are Going: Sadat, Nixon, and the Soviet Presence in Egypt, 1970–1971,” Middle East Review of International Affairs, Vol. 8, No. 1 (March 2004), p. 14. 192. Memorandum of Conversation of a National Security Council Meeting, February 26, 1971, 11:45 A.M., FRUS 1969–1976, Vol. 23, pp. 761–762. 193. Telegram from the Department of State to Certain Diplomatic Posts, January 16, 1969, 0204Z, FRUS 1969–1976, Vol. 23, p. 8 194. Minutes of a Senior Review Group Meeting, January 11, 1971, 10:55–11:45 a.m., FRUS 1969–1976, Vol. 23, p. 692. 195. Telegram from the Department of State to Certain Diplomatic Posts, pp. 10–11. 196. National Security Study Memorandum 2, January 21, 1969, FRUS 1969–1976, Vol. 23, p. 11. Kissinger also notes the continuing U.S. efforts to court Egypt. See Henry A. Kissinger, Years of Upheaval (New York: Little, Brown, 1982), pp. 204–206. 197. Quotes from Memorandum from the President's Assistant for National Security Affairs (Kissinger) to President Nixon, November 27, 1971, FRUS 1969–1976, Vol. 23, pp. 950–951. 198. Ibid. 199. Ibid. 200. Pollock argues that this package might have been linked to Israel's agreement to “proximity talks” on an interim Suez accord. See Pollock, Politics, p. 126. 201. Intelligence Memorandum Prepared in the Central Intelligence Agency, June 1973, FRUS 1969–1976, Vol. 25: Arab-Israeli Crisis and War, 1973 (Washington, D.C.: GPO, 2011), pp. 195–198. 202. Uri Bar-Joseph, “Last Chance to Avoid War: Sadat's Peace Initiative of February 1973 and Its Failure,” Journal of Contemporary History, Vol. 41, No. 3 (July 2006), p. 549. 203. Ibid.; and Quandt, Peace Process, p. 93. 204. Memorandum for the Assistant to the President for National Security Affairs, February 27, 1973, folder “Israel Vol. 11: October 1972–Feb 1973,” box 610, Country Files, NSC Files, RMNL. 205. Memorandum for the President from Henry A. Kissinger, May 17, 1973, folder “Israel Vol. 12: Mar 1973–Oct 1973,” box 610, Country Files, NSC Files, RMNL. 206. For a discussion of emergency aid, see Memorandum from Secretary of Defense Schlesinger to President Nixon, November 1, 1973, FRUS 1969–1976, Vol. 25, p. 804. 207. “The U.S.-Israeli Military Relationship.” 208. Memorandum for the President, January 6, 1966, folder “Israel, January 1965–March 1966 [1 of 4],” box 29, Files of Robert W. Komer, National Security File, Lyndon B. Johnson Presidential Library, Austin, Texas. 209. For similar conclusions, see David Rodman, Arms Transfers to Israel: The Strategic Logic behind American Military Assistance (Brighton, U.K.: Sussex Academic Press, 2007); and Pollack, Politics, p. 295. 210. See, for example, Memorandum from Secretary of Defense Laird to President Nixon, June 5, 1970, FRUS 1969–1976, Vol. 23, pp. 405–406; Memorandum for the Record, June 10, 1970, FRUS 1969–1976, Vol. 23, p. 423; and Memorandum from the President's Assistant for National Security Affairs (Kissinger) to President Nixon, June 16, 1970, FRUS 1969–1976, Vol. 23, pp. 439–140. 211. Our analysis shows that commercial considerations occasionally affected the timing of arms transfers. Nevertheless, we imagine that commercial motivations for transferring arms could become prominent when the security risks associated with providing weapons are small. 212. McManus and Yarhi-Milo, “The Logic of ‘Backstage’ Signaling.’ 213. Ashton Carter, “A Regional Security Architecture Where Everyone Rises,” speech delivered in Singapore, May 30, 2015 (Washington, D.C.: U.S. Department of Defense, 2015), http://www.defense.gov/Speeches/Speech.aspx?SpeechID=1945. 214. Aaron Mehta, “Carter Announces$425M in Pacific Partnership Funding,” DefenseNews, May 30, 2015, http://www.defensenews.com/story/defense/2015/05/30/carter-announces-425m-inpacific-partnership-funding/28206541/.

215.

David Stout, “Top U.S. General Says Washington Should Consider Arming Ukraine,” Time, March 4, 2014, http://time.com/3731247/us-arm-ukraine-russia-general-martin-dempsey-putin/.

216.

Ivo Daalder et al., “Preserving Ukraine's Independence, Resisting Russian Aggression: What the United States and NATO Must Do” (Washington, D.C.: Atlantic Council, 2015), http://www.thechicagocouncil.org/sites/default/files/UkraineReport_February2015_FINAL.pdf.