In the 1960s and early 1970s, U.S. policymakers maintained a complex effort to limit the dissemination of gas centrifuge technology for enriching uranium, which they saw as an inherent nuclear proliferation risk. Recognizing that controls could not stop scientific research and development, U.S. officials nevertheless believed the overseas development of gas centrifuge technology could be slowed. To prevent further dissemination overseas, the United States supported cooperation with European allies that were already developing the technology. Cooperation involved implementation of secrecy and export controls, although a U.S. initiative to include Japan failed because nuclear secrecy was incompatible with Japanese law. The United States tried to deflect Japan's interest in the gas centrifuge by offering to share an alternative technology, gaseous diffusion, for enrichening uranium. That initiative failed, but the U.S. government remained committed to keeping enrichment technologies under secrecy controls.

The international agreement in 2015 that required Iran to limit its gas centrifuge uranium enrichment facilities underscored the political sensitivity of that technology. As far back as the 1950s and 1960s, senior U.S. and West European officials worried that the gas centrifuge process posed a significant nuclear proliferation risk because it could be used in small, secret plants to enrich uranium (as Iran was caught doing much later). Illustrating the risk was a report in the spring of 1966 to surprised members of the U.S. Atomic Energy Commission (AEC) disclosing that a U.S. firm, Electro-Nucleonics, with no access to classified information, had established a “primitive” gas-centrifuge capability and was confident that it could demonstrate the production of small amounts of weapons-grade highly enriched uranium.1 This revelation reinforced concerns among AEC officials who, as part of their responsibility to facilitate the “peaceful atom,” had seen the gas centrifuge as a significant challenge to nonproliferation policy. In 1960 that perception had created such concern that the United States, the Netherlands, the United Kingdom, and West Germany agreed to put their gas centrifuge research and development programs under secrecy controls. Yet the pro-classification consensus was less than robust, and U.S. officials feared that leaks could spread the technology to nationalist and Communist adversaries. Another ally, Japan, was also developing the gas centrifuge process but without government secrecy controls.

In the late 1960s AEC officials saw a potential proliferation hazard and a challenge to the U.S. nuclear reactor fuel monopoly when the British, Dutch, and West Germans agreed to combine their gas centrifuge research and development (R&D) to produce reactor fuel. In this connection, the British posed special problems, not only by questioning gas centrifuge secrecy but also by seeking to share gas centrifuge information with their partners, including information acquired through secret UK-U.S. technology exchanges. The fact that one member of the tripartite project, the Federal Republic of Germany (FRG), was a former enemy sparked anxiety among the French, who still harbored memories of Nazi aggression.2 Moreover, the secrecy surrounding the gas centrifuge process raised questions about the safeguards system the International Atomic Energy Agency (IAEA) would be developing to ensure non-military uses of the technology.

This article seeks to explain how the U.S. government shaped policies responsive to the security and economic challenges raised by the gas centrifuge process. Concerned that nuclear proliferation could weaken U.S. power, complicate diplomacy, and raise risks of nuclear war, U.S. policymakers sought to minimize the complications associated with the gas centrifuge by tightening controls and forging a pro-secrecy consensus with European allies, although they could not reach agreement with Japan. When the British-Dutch–West German project emerged in 1968–1969, senior officials found it advantageous on nonproliferation grounds and did not openly oppose it despite the objections of the AEC and the fears of the French. The U.S. government deflected the British proposal to reduce secrecy and found ways to avoid an Anglo-American rift over the vexing problem of the transfer of gas centrifuge secrets. Yet as a result of the AEC's objections, the Nixon administration did not wholly accommodate itself to the tripartite project and made an unsuccessful attempt to delay it by offering uranium enrichment technology to West European countries.

With the recent surge of scholarship on the history of nuclear proliferation and nonproliferation policy, the story of gas centrifuge technology and the diplomacy surrounding it has been explored by historians and social scientists.3 A significant body of work has focused on such topics as the origins of the gas centrifuge, the emerging concerns over proliferation risks and the quest for secrecy, the British and Dutch gas centrifuge projects, the origins of the tripartite British-Dutch–FRG cooperative gas centrifuge project, and the related Anglo-American negotiations over nuclear data transfers to the project. Yet the main lines of U.S. policy in the 1960s and 1970s remain understudied and somewhat misunderstood.4 Despite claims to the contrary, U.S. policymakers did worry about the possibility of clandestine gas centrifuge plants and appreciated “political solutions” to the problem of nuclear proliferation. For them, technological superiority and secrecy agreements were valuable but insufficient for managing the risks. They were not confident that controls could prevent military uses of gas centrifuge technology, and at best they hoped that international agreements and technology sharing could slow the rise of proliferation challenges. Moreover, to the extent that other countries developed the gas centrifuge process on their own, the Nuclear Nonproliferation Treaty (NPT) provided safeguards to ensure non-military applications.5

A close look at U.S. efforts to prevent the spread of a sensitive technology provides an instructive example of the complex problem of reaching and maintaining nonproliferation agreements. Even in an age of U.S. hegemony, the United States needed the help of allies to establish and enforce controls over gas centrifuge technology. Those same allies would be competing with the United States for reactor fuel markets, but competition was tempered because tough positions toward the tripartite project could alienate close U.S. associates and weaken the consensus around gas centrifuge secrecy. Yet events of the 1970s through the 1990s—A. Q. Khan's theft of European gas centrifuge plans for Pakistan's nuclear bomb project and his later sale of the technology to other countries—undermined U.S.-European control efforts. The importance of those developments for world politics makes it worthwhile to look into the deep background and to review Washington's complex efforts to manage the problem of gas centrifuge technology and the policy dilemmas it raised.

The account provided here is based solely on U.S. records. How the British, Dutch, and West Germans, as well as the French and the Japanese, interpreted U.S. efforts to keep the gas centrifuge process secret and to restrict access to the technology is an important part of the history and could shed light on the impact of U.S. policy. Nevertheless, given Washington's central role in advancing the program of denial and secrecy and its complex relationship to the tripartite project, the story of how U.S. policy developed during the 1960s and early 1970s needs recounting for the light it sheds on the history of nuclear nonproliferation policy. Perhaps this account will encourage researchers to dig up more of the story and thereby make possible a broader history of gas centrifuge diplomacy during this significant period.6

Shaky Status Quo

A key moment in the story of Western efforts to control gas centrifuge technology came in 1960, when the AEC concluded that recent advances in the technology posed a significant nuclear proliferation threat by making it possible for determined governments to produce fissile material for nuclear weapons. Interconnected cascades of rapidly spinning centrifuges could process uranium gas and separate light uranium molecules from heavy molecules to produce U-235 for use in nuclear weapons. Thanks to developments in Soviet technology transferred by former prisoner of war (POW) Gernott Zippe, the United States was able to fashion a workable gas centrifuge design. Although functional gas centrifuge cascades did not yet exist in the West, studies by the AEC and Oak Ridge National Laboratory in Tennessee demonstrated the possibility of operating them in small clandestine facilities to produce fissile material. By contrast, the gaseous diffusion method required huge plants and massive inputs of electricity to produce enriched uranium.7

The Eisenhower administration, like its successors, worried about the “Nth” country problem, the prospect that an indeterminate number of states would become nuclear powers after the United States, the Soviet Union, the United Kingdom, and most recently France. In this connection, senior U.S. officials worried about the acquisition of nuclear weapons by nationalist governments in places such as Brazil or by otherwise “obstreperous” states, including political and ideological adversaries such as Cuba and China (that Beijing already had access to Soviet gas centrifuge technology was not yet known in the West).8 In particular, the risk that nuclear proliferation could complicate superpower relations, raise the danger of local conflicts triggering nuclear war, and crimp U.S. freedom of action in world affairs order continued to stoke official concern.9

To limit nuclear proliferation, officials at the AEC and the U.S. Department of State believed that secrecy to restrict access to gas centrifuge technology was necessary, if only as a stop-gap until an effective system of international safeguards was in place. To prevent leakage of sensitive information, they wanted to extend the reach of the secrecy system to allies that were also developing the gas centrifuge. Giving impetus to the quest for secrecy was the concern that U.S. firms interested in the commercial potential of the gas centrifuge were unlikely to accept restrictions unless the Dutch and the West Germans accepted them.10 Thus, a superpower needed the help of allies to extend nuclear secrecy. Scientists and diplomats on both sides of the Atlantic had doubts about the desirability or efficacy of using secrecy and export restrictions to control scientific development, but the British, Dutch, and West Germans agreed to cooperate, saying they shared Washington's anxiety. A complicating matter was that West German action to classify R&D would raise questions about whether the FRG had secret military aims. That, however, was not a major obstacle, and the diplomatic process yielded the makings of what became known as a “gentlemen's agreement” to classify gas centrifuge R&D and to maintain export controls. The gendered language reflected who was making policy in those days, but it also conveyed the informal nature of the process.11

With one exception, the four governments did not share gas centrifuge R&D with one another because they were developing it for their own commercial-industrial purposes. Although the AEC was making investments in the gas centrifuge process to maintain a technological lead over rivals, it shared some advances with the British. As part of the U.S.-UK special nuclear relationship, the 1955 Civil Uses Agreement permitting the exchange of data on isotope separation methods led to an arrangement, reached in 1960, to share information derived from gas centrifuge R&D. The degree to which the British gas centrifuge program had drawn on classified U.S. innovations became important in the late 1960s when the UK began talks with the Dutch and West Germans to pool their R&D.12

Two nuclear states, France and the Soviet Union, were on the outside of the quadripartite understanding. Having already made major investments in the gaseous diffusion process to enrich uranium for their military program the French did not have strong incentives to explore the gas centrifuge option. U.S. officials did not want the technology to leak to France or other members of the European Atomic Community, but they kept French diplomats apprised of the understanding, assuring them that the FRG was taking a “constructive and responsible” position. According to one source, the four governments at some point in the 1960s “invited” France to participate in the understanding, but the French turned the offer down.13 As for the Soviet Union, a few U.S. officials briefly discussed the possibility of a cooperative gas centrifuge development program, but after the U-2 crisis and the collapse of the Paris summit in May 1960 that notion faded away. U.S. intelligence knew little about Moscow's significant advances with gas centrifuge technology and the expertise it shared with Beijing before cooperation stopped in June 1959. As Washington learned, Soviet official were “worried” about the security implications of the gas centrifuge because the POWs who had assisted them had returned to East and West Germany. This probably fed into anxieties about a nuclear FRG and Moscow's developing interest in a nuclear nonproliferation agreement with Washington, but Soviet leaders were not worried enough to make West German gas centrifuge R&D a cause célèbre.14

In the wake of the initial decision to classify the gas centrifuge process and subject it to export controls, the four governments met periodically to evaluate their informal understanding and its application and to discuss whether new measures were necessary. These discussions disclosed areas of disagreements, mainly over the registration of patents, but the classification system stayed in place, even though some of the participants became restive. Giving impetus to U.S. government efforts to maintain the pro-classification consensus was that President Dwight Eisenhower's successors, John F. Kennedy and then Lyndon B. Johnson, were deeply concerned about the spread of nuclear capabilities, not only to Third World countries but to close associates and allies such as Israel and West Germany. In this policy environment, the “gentleman's agreement” and related measures to curb the proliferation of gas centrifuge technology were as relevant as ever.15

The first review meeting took place in Washington, DC, in early March 1962, organized by the AEC in response to queries from the Dutch and West Germans about the classification guide provided by the United States in August 1960. The AEC guide provided “common principles” for the classification system; thus, information on the design, construction and operation of gas centrifuge cascades was classified secret “restricted data,” as was the design of plants and pilot plants, plant operations, uranium gas flows, and any “new steps,” among other topics. Moreover, information that by itself was declassifiable could not be released if it would directly or indirectly shed light on “classified processes.” Having started to follow these guidelines, the quadripartite representatives discussed the “philosophy” that informed their approach to secrecy and the rules and regulations that followed. To formalize their understanding, they agreed to use the literature published as of 1 August 1960 as a dividing line for determining what was unclassified. That would provide a common standard when disagreement arose over whether information could be declassified. Yet to avoid revealing commercial-industrial secrets to one another, the participants did not discuss details about the gas centrifuge process.16

The only area of controversy was whether any of the four participants could file classified patents on gas centrifuge technology in other countries. To prevent the technology from leaking beyond the sphere of the “gentleman's agreement,” the AEC wanted to limit patent filings to the four countries in which the programs were protected by classification and security arrangements. Moreover, from the U.S. perspective, agreements of cooperation regulating the exchange of restricted data were necessary for filing such patents. Thus, patents could be filed in Canada because Ottawa and Washington had the necessary agreements in effect.

The Dutch rejected that argument. So long as the country in which the patent was being filed had “adequate security arrangements,” the Netherlands wanted to be able to file “in as many countries as possible,” regardless of whether an agreement of cooperation was in place. That was important because “denial of the right to file could damage the interest of the investor.” In practice that would mean filing in only other North Atlantic Treaty Organization (NATO) member states, where “secrecy orders” could safeguard classified patents. The group did not reach an understanding, although the Dutch and West Germans agreed to provide “advance notice” of any plans to file classified patent applications.17 On a related matter, the U.S. side agreed to consider a Dutch–FRG request to “honor the secrecy” of patents that their nationals filed in the United States.

In 1963, the AEC proposed discussions to formalize the secrecy understanding, but not until early 1964 did one of the governments, the Netherlands, respond in support of the U.S. call for a meeting. In part, because of technological developments, the Dutch wanted to review the classification guide to see whether any changes were necessary. Thinking along the same lines as the AEC, the Dutch revived an earlier proposal for the four governments to codify the classification agreement through an exchange of notes, thereby ensuring that future governments protected secrecy for the long term. Worried that one of the parties to the understanding might change its mind, the Dutch believed that a more formal agreement would give their government and “industry complete assurance that all countries concerned are … under the same restrictions.”18

The AEC supported the Dutch proposal and wanted to settle the vexing problem raised by patent secrecy. Using “secrecy orders” to maintain security, the Dutch had been filing centrifuge patents in NATO countries, including France and Italy, but the AEC's Division of Classification objected. Concerned about laxness in West European secrecy systems, it perceived that “lost filings” could “compromise significant … information.”19

In March 1964 when the AEC delegation, led by Myron Kratzer, deputy director of the Division of International Affairs, met near Bonn with the other partners, it learned that the consensus for classification was weakening. When the U.S. team raised the possibility of an intergovernmental agreement, the Dutch showed no interest, despite their recent proposal. Indeed, they showed some indifference by observing that a “process of erosion will undoubtedly result in the relaxation of the rigid classification requirements.” What caused this change of heart remains to be discovered. Meanwhile, an internal proposal by the FRG Ministry of Scientific Affairs indicated that important elements in Bonn were becoming restive about secrecy. The ministry proposed ending the secrecy system, but the Foreign Ministry “overruled” the proposal, probably to avoid controversy with Washington on a sensitive issue. Thus, Kratzer reported that the Dutch and West Germans were “reluctant partners” to the four-power understanding and that it might require “political representations at a high level” to keep them in the fold. That did not prove necessary, but Washington was not pleased that the Dutch, despite their initial acceptance of proliferation concerns, told other governments, including the United States, that they had classified the technology only because Washington had asked them to do so.20

The four governments agreed to preserve the informal understanding, but they did not reach agreement on where classified patents could be filed. Opposing the U.S. view that classified patent filings should be limited to the four countries, the Dutch and West Germans wanted to “remain free” to file in any country with arrangements for classified patents. The Dutch, as before, stated they would limit their filings to NATO countries.21

Tightening the Controls

At the time of the meeting in Bonn, AEC contractor Union Carbide Nuclear Company turned in a major report on the problems raised by the gas centrifuge proliferation, the “Nth Power Evaluation.”22 This report fed into a general move to tighten controls that accelerated in the next few years with growing U.S. concern over nuclear proliferation risks.

The Union Carbide analysts found that even countries with “relatively little technical skill” could develop the gas centrifuge process if they had technical advisers, knowledge of U.S. developments, and imported equipment. A survey of U.S. intelligence reporting and open literature pertaining to countries outside the Soviet bloc indicated that the United States, West Germany, Britain, the Netherlands, and Japan were the only ones that had “serious” R&D programs under way. A few countries with “limited industrial sectors,” such as Israel and Yugoslavia, were conducting some R&D. Brazil, which had acquired several rudimentary gas centrifuges from the FRG in the 1950s, was also conducting research, although it was “doubtful that any real contribution … will be made.”

Given the proliferation risks, the Union Carbide analysts reaffirmed that export controls and classification programs to restrict the spread of gas centrifuge technology were “highly desirable.” Declassification of gas centrifuge technology would “increase the number of countries which might obtain a nuclear capability.” The declassification of future R&D work on the technology would have an “even more pronounced effect” because it was likely to make the centrifuge “more attractive from the standpoint of both time and money” compared with extracting plutonium from spent reactor fuel.

In light of such findings, the AEC wanted to go further in reducing the proliferation threat. Recognizing that “despite our best efforts” the technology “will eventually be acquired by ‘Nth powers,’” Chairman Glenn Seaborg supported a policy of “achieving maximum delay.” With the Johnson administration already worried about the problem of nuclear proliferation and its threatening implications for the U.S. international position, the AEC's interest in tightening controls found strong support in the national security bureaucracy. The director of the U.S. Arms Control and Disarmament Agency (ACDA), William C. Foster, suggested that achieving delay would be helpful until a global nonproliferation system was in place and that “we delay such dissemination as long as we can.” Secretary of Defense Robert McNamara also endorsed the objective of “maximum delay,” suggesting that “the goal of retardation” was a “worthwhile one” that could be met through disincentives and security controls. Offering “attractive terms” on enriched uranium available as reactor fuel could “dampen the incentive” to develop gas centrifuges, while international safeguards on sales of natural uranium could stymie would-be proliferants. Finally, McNamara supported AEC programs along with “stringent security controls” to ensure that the United States stayed “abreast, or ahead, of developments” elsewhere.23

With new technological innovations in sight, the AEC tightened domestic controls to “keep the genie bottled up.” Removing gas centrifuge technology from the AEC “access permit” program, U.S. corporations would no longer be able to use information developed by the AEC. Such firms, including General Electric and Allied Chemical, could continue their R&D work, as could other companies that never had access to AEC data. As Seaborg later explained, severe measures would “strengthen the U.S. position with foreign governments with respect to our determination to prevent the dissemination of this information.”24

One move toward more restrictions involved the termination of gas centrifuge information exchanges with the British. On 30 June 1964 Secretary of State Dean Rusk wrote to Seaborg “urging consideration of curtailment of the current exchange of information with the United Kingdom.” In keeping with the strongly restrictive approach that had developed, Rusk worried about the risks of leaks and wanted to minimize them: “It would be most unfortunate if the United States were to become the source of disseminating this technology.” The AEC accepted the suggestion and soon ruled against passing “any new technical information” to the British on the grounds that the U.S. gas centrifuge program was now generating “production technology” for potential industrial application, which could not be provided under the terms of the civil uses agreement. To that extent, the AEC was applying the “retardation” approach by prohibiting the transfer of new data. During the final year of the agreement, expiring in July 1965, the British Atomic Energy Authority received only general information regarding the status of the U.S. program on the condition that it “not be passed to industry.”25

Insiders like National Security Council (NSC) staffer Spurgeon Keeny were not so sure that tightening up would work. With the “basic facts” already known, gas centrifuge secrets could be cracked because they were “largely engineering in nature.” While Keeny supported the drive to control the technology, he later wondered whether the AEC was “as really concerned as they claim to be about the gas centrifuge problem or whether they have seized upon a peripheral issue on which to demonstrate their sincere concern about non-proliferation.” For Keeny, it was a side issue because it was “very unlikely that Nth countries would in fact base their weapons program on this technology.” Implicitly, Keeny saw the plutonium route as the most likely path to nuclear weapons development, a view shared by Seaborg, although developments in later years partly invalidated it.26

The AEC's restrictive approach created suspicion in the FRG, a country in which the “basic facts” were known. According to Myron Kratzer, “circles” around Bonn's Ministry for Scientific Research believed the AEC had achieved an unspecified gas centrifuge “breakthrough” that showed how competitive the technology was compared to the gaseous diffusion method. West German officials also believed that with the AEC cutting back on gaseous diffusion production for weapons it had “excess diffusion plant capacity” and wanted to “restrict competition by blocking the development of the alternate gas centrifuge method.” Kratzer disputed none of these lines of thought. The AEC did have ample gaseous diffusion production capacity and surplus reactor fuel that was not needed for military purposes. To discourage other countries from establishing enrichment facilities and possibly to preserve the value of the huge U.S. investment in an older technology, the AEC had been following, as McNamara had suggested, a liberal reactor fuel supply policy to forestall the creation of enrichment facilities overseas.27

Bonn's interest in reducing dependence on U.S. nuclear fuel supply and apprehension that the United States had made a “breakthrough” may have influenced it to undertake an early attempt at technological cooperation in late 1964 and early 1965: a centrifuge research program with the Netherlands. The West Germans had been talking to the British and the French about uranium enrichment possibilities, but the Netherlands was the only country with which they had discussed the gas centrifuge. With progress slow in both countries, they saw cooperation as a way to save money and accelerate R&D. Privately, the Dutch saw that working with their former enemy would give them a “say” in any FRG uranium enrichment plans but also provide Bonn with an alternative to nuclear cooperation with Paris (which Washington also opposed). Apparently, the West Germans had discussed a possible U.S. role in a joint project, but some preferred to work with the Dutch only.28

The AEC reacted negatively to the project. According to Kratzer: “We have attempted to dissuade the two Governments from proceeding … by stressing the mutual desirability of restricting the dissemination of gas centrifuge technology.” Kratzer objected to the sharing of technical data even between states with classified programs, perhaps because doing so might lead to the production of a better machine that could inadvertently leak to proliferants or eventually produce significant competition for reactor fuel sales. In any event, he ruled out U.S. participation in the joint venture because it would involve the exchange of restricted data, which would be possible only with formal agreements for cooperation, and the AEC was unwilling to initiate them.29

AEC objections did not prevail, although the project broke down in any event. The U.S. State Department weighed in by stipulating that Washington would accept Dutch–FRG cooperation only if it complied with the “agreed classification policy.”30 Citing nonproliferation concerns, both the West Germans and the Dutch assured Washington that their joint venture would follow the 1960 classification agreement. What happened next is unclear from the available U.S. record. Apparently, the Dutch government halted the discussions in late 1966 because of unspecified “political objections.” This disappointed at least one FRG official who claimed that West German gas centrifuge technology was “not good.”31 But that was not the end of the story of Dutch–West German cooperation.

Also in 1966, an AEC task force on the implications of the gas centrifuge for nuclear proliferation, chaired by Assistant General Manager Howard Brown was reaching conclusions that influenced decisions to tighten domestic controls even further. The discovery of Electro-Nucleonic's progress in mastering the gas centrifuge process bolstered the task force's apprehensions. Seeing a repetition of that situation overseas as a significant risk, the task force found, as had earlier studies, that the availability of “gas centrifuge technology could accelerate or increase proliferation.” Indeed, countries undertaking nuclear weapons programs could use a nuclear-generated electric power program as a convenient cover for developing gas centrifuge technology. Moreover, contrary to Keeney's thinking, the same countries might find it preferable to develop highly enriched uranium–fueled weapons instead of using “dirty” plutonium, which, even if it was relatively cheaper, raised difficult handling problems.32

With “significant advances” being made in developing more advanced, higher speed, and gas centrifuge designs, the task force worried that too much sensitive information was available to U.S corporations. The possibility of a “breach of containment” between the various compartments of information held by the AEC and the companies shaped an AEC decision, taken in March 1967, to eliminate the access permit program altogether. Except for designated contractors, the AEC prohibited corporations from doing gas centrifuge research in the United States. Because other firms had been interested, the AEC reasoned that continuing the practice “would have multiplied substantially [the] number of people with access to sensitive information and statistically would have increased [the] possibility of inadvertent disclosures.”33

When discussing security and classification problems, the AEC task force raised a question about the application of IAEA safeguards for enforcing an NPT. Noting that the safeguards had not yet been applied to “any significant isotope separation facility,” the task force saw a danger that the technology could be disseminated “through the inspectors.” This hazard had to be mitigated because inspection was necessary to ensure that “all the product of a facility may be accounted for.” The AEC, however, did not yet have a proposal to do so for reducing the risk, but the problem received greater attention in the future.

Before the AEC announced its tighter controls over corporate research, the “quadripartite group” had one of its periodic meetings in London. With the AEC policy review confirming the need for gas centrifuge secrecy, the purpose of the proposed discussion was to “reaffirm” existing classification arrangements, to make another go at a formal intergovernmental agreement, and to discuss the need for classification understandings with other governments.34

Although at least one senior FRG official saw no point to a meeting, the four governments agreed to convene in London in mid-February 1967. When the AEC–State Department delegation, led by Kratzer, met with their counterparts in the FRG, they tried to disabuse their partners of the notion that the United States had made a “technical breakthrough.” Nevertheless, dissent on secrecy had “lessened,” and the participants “agreed to continue as in the past.” On patents, the Dutch claimed a “theoretical right” to file classified patents outside NATO countries, but they had not done so, and the West Germans and British had not filed outside the “four.” Even so, all three wanted the option to file outside of NATO “upon prior consultation” with the others.35

The Japan Conundrum

During the London meeting, the U.S. representatives mentioned that they wanted to ask the Japanese to classify their gas centrifuge R&D, which they had conducted at the Tokai-Mura Laboratory since the early 1960s. The Dutch, West Germans, and British supported the initiative but wanted Tokyo's participation in the group subject to general approval. Influencing the search for Tokyo's cooperation was deep concern over the Chinese nuclear weapons program and growing interest in working with allies to deny Beijing access to sensitive technology. The AEC scheme, however, turned out to be futile. Japan's legal system had no place for nuclear secrecy. All the same, the discussions raised important questions about the limits of nuclear secrecy as well as the implications of an NPT for U.S. efforts to prevent the spread of sensitive technology.36

The AEC proposal for Japan to classify gas centrifuge technology met early resistance from the U.S. embassy in Japan. In several messages signed by Ambassador U. Alexis Johnson, the embassy essentially informed the AEC that its objectives were practically impossible. For example, the work at Tokai-Mura Laboratories and the Tokyo Institute of Technology had only proprietary protection because Japan had no information security laws that could protect nuclear-related technology, and there was “little chance” of bringing about legal change. Even if such laws existed, enforcement would be “extremely difficult” because the existence of a “left-wing faction” at Tokai-Mura raised security risks. Moreover, if Washington insisted on pressing for classification, it could focus disproportionate attention on a program that was making only “modest progress.”37

The embassy's point about Japanese law was a central problem. Influenced by scientists who wanted to prevent secret weapons research, Japan's 1955 atomic energy law included principles of peaceful use, public disclosure, and democratic management. As Hirohiko Otsuka of the Japanese Foreign Ministry's UN Branch later explained to Whittie J. McCool, the AEC's representative in Japan, the law “currently excludes classification of technical data,” and he saw “little hope” of amending it.38

The AEC was stubborn, and after back-and-forth communications with the embassy, the latter delivered a message to the Foreign Ministry in mid-April 1967 asking for consultations. After receiving no response, the State Department asked the embassy in June to “reaffirm our interest” to the Foreign Ministry.39 After another try by the embassy, Japanese diplomats informally and then officially responded negatively, making the point that the U.S. embassy had anticipated, namely, that nuclear secrecy was incompatible with Japanese legislation requiring “public disclosure” of nuclear information.

For some Japanese officials the NPT offered a solution, although they could not persuade the State Department. A Japanese Foreign Ministry official, Masahisa Takigawa, suggested that the NPT might “take precedence over domestic law and … become a potential mechanism for establishing control over the outflow of technical information.”40 Disagreeing that the NPT could provide such a “mechanism,” State Department officials believed that safeguards could prevent the misuse of sensitive technology. Nevertheless, they were mindful that Article IV of the treaty spelled out an “inalienable right” of treaty parties to disseminate and develop peaceful nuclear technology, which could make it “more difficult than before to restrict the flow of information resulting from research in nominally peaceful nuclear technology.” That concern made the State Department reluctant to link the nonproliferation treaty to gas centrifuge classification because it could be “misinterpreted as US effort [to] apply NPT provisions to hamper research efforts of other countries in areas where we have head start.” Such a linkage would “incorrectly burden NPT with antagonism of other countries already resentful of presumed progress of US, Japan and few others in this field.”41

The Japanese wanted to discuss gas centrifuge controls more fully with U.S. officials and proposed that an “experts conference” on the NPT serve as a cover for informal talks. Washington eventually agreed to send to Tokyo a small group, including ACDA Deputy Director for Science and Technology Herbert Scoville and AEC Assistant General Manager Howard C. Brown. They met with Atsuhiko Yatabe, the chief of the scientific section of the Foreign Ministry's UN bureau, among other officials. During the meetings, the U.S. group sought to dispel concerns that Washington was trying to check Japan's capabilities to produce nuclear fuel. They stressed that they had “no intention … of placing any restrictions on the research and development of methods for the manufacturing of enriched uranium.” Recognizing that legal classification was not possible, the U.S. representatives asked the Japanese to look into ways to control the proliferation of the technology “through some [other] proper means,” such as commercial secrecy.42

State Department officials had already raised that possibility in earlier discussions with Japanese diplomats, and Japanese newspaper stories had mentioned commercial secrecy. The Japanese saw potential in using private corporate control because it was legitimate for a company to “keep a scientific technique secret” to preserve its profits. Nevertheless, if a company applied for a patent to protect an innovation, it could not prevent public release because “there is no system for secret patents.” Moreover, as a Japanese diplomat observed, commercial secrecy had its limits when it “threatens to inhibit marketing [of a] Japanese centrifuge.”43

The secret talks drew no conclusions and Tokyo made no commitments beyond a “promise [to] think over the question.” If follow-up discussions ever took place, the paper trail from them has not surfaced. Nevertheless, the Japanese came to rely on commercial confidentiality to prevent the dissemination of gas centrifuge technology. Precisely how this happened is as yet unknown, but a 1974 U.S. embassy report underscored the change, noting that Japan “has effectively controlled [gas centrifuge technology's] dissemination on the basis of its proprietary nature,” even though “basic facts” about the gas centrifuge program “are in the public domain.”44

The Tripartite Project and the Challenge to the U.S. Monopoly

Washington took in stride Japan's inability to accommodate governmental nuclear secrecy, but a new challenge to the policy of denial lay ahead. In 1968–1969 the British, Dutch, and West Germans began discussions of a cooperative gas centrifuge development project. For the first time, a major program for the industrial-commercial application of the gas centrifuge process was under way, with significant implications for U.S. preeminence in world reactor fuel markets, the gas centrifuge secrecy regime, and the nonproliferation system generally. This would produce diplomatic complications, owing to disagreements over British proposals to reduce secrecy and to transfer data from previous U.S.-UK technology exchanges to Britain's partners. Moreover, U.S. officials were divided over the merits of the tripartite project, with the AEC tending to see a danger and the State Department taking a “benevolent” position, seeing any U.S. interference as disruptive of trans-Atlantic relations.45

That the European participants in the “gentlemen's agreement” were taking a new approach became evident in the late winter and early spring of 1968. Media reports on the Dutch and West German gas centrifuge program indicated technological advances, Dutch interest in revising the secrecy agreement so they could collaborate with other countries, and the FRG's reluctance to build a pilot enrichment plan if it were to antagonize the Soviet Union. Privately the Dutch had resumed talks with the West Germans, and the British were keenly interested in reaching agreement with both governments. Through a cooperative project with the Dutch and West Germans, the British believed they could achieve important technological, economic, and diplomatic goals: improving centrifuge designs, developing reactor fuel markets, increasing their prospects of joining the European Communities, and ensuring that West German centrifuge R&D was limited to civilian purposes.46

On 12 April 1968, before beginning discussions with the Dutch and West Germans, the British proposed to Washington, on a highly secret basis, special talks to gauge U.S. attitudes toward the new project and its implications for the NPT. The British overture remains classified, but apparently officials in London worried that gas centrifuge technology posed difficult problems for the safeguards system required by the then-unsigned treaty. Governments might not sign if they believed that some countries would evade the treaty by building secret enrichment plants. Moreover, some governments, such as the Netherlands and FRG, might not permit IAEA inspection of their centrifuge cascades.47

At a meeting with British diplomats on 16 April 1968, Deputy Under Secretary of State Charles E. Bohlen presented talking points suggesting that the talks proposed by the British could raise the risk that “other governments might misunderstand their purpose.” From the State Department's perspective, the status of gas centrifuge technology had no bearing on whether the NPT should be signed or ratified. The treaty would in no way inhibit countries from developing gas centrifuge technology so long as the development was for peaceful purposes and the enriched uranium was subject to safeguards. Taking any other position could limit the treaty's “acceptability … to a number of important potential signatory nations.”48 In any event, the possibility that the gas centrifuge was reaching practical application made agreement on the NPT even more important to ensure that signatories did not use enrichment technology for military purposes. As for safeguards, the U.S. side agreed that the gas centrifuge process raised difficulties but that further research, including investigations by the IAEA, could resolve them.49

Responding to British queries about the U.S. position on the European gas centrifuge project, Bohlen said it was “natural and appropriate.” Even though Washington did not seek to “encourage” such projects, the previous understandings on classification did not “preclude classified cooperation between participating countries.” Accordingly, Washington preferred that the project be limited to the British, Dutch, and West Germans because if others were involved there would be “pressures to disseminate information.” Bohlen also emphasized the importance of British adherence to the 1955 U.S.-UK Civil Uses Agreement, which had facilitated exchanges of gas centrifuge R&D and prohibited the dissemination of any U.S. data the British had incorporated in their centrifuges.50

On 16 April 1968, when Dutch Foreign Minister Joseph Luns met with British officials to discuss the possibility of cooperation, Luns disclosed the Dutch–West German talks. By then the British were about to hold discussions with the FRG. That Bonn was divided over the NPT was a problem, but the British believed their concerns could be eased if the West Germans firmly pledged that project resources would not be diverted for military purposes. At that point there was no possibility of locating a tripartite enrichment plant in the FRG. Both the Dutch and the British opposed it, and Bonn wanted to avoid fueling Soviet concerns that could harm Ostpolitik. By early November 1968, the three governments were ready for a ministerial-level meeting to discuss the proposal.51

Even though the U.S. State Department had given its blessing for the project, some AEC officials voiced opposition. Not wanting to lose existing U.S. reactor fuel markets and revenue streams and seeing a proliferation threat in almost any overseas enrichment project, staffers at the Division of International Affairs believed in doing “everything we can to discourage the construction of an isotope enrichment plant.” AEC Chairman Seaborg had not taken a position, but Commissioner Wilfrid E. Johnson contemplated a policy to “prevent, delay, or limit” European plans by either liberalizing access to U.S. fuel supplies or dampening interest in the gas centrifuge by sharing gaseous diffusion technology, which would be more difficult to develop on a clandestine basis. State Department European experts believed the AEC's position was based on narrow commercial and nonproliferation considerations. According to Abraham Katz of the Office of European Regional Affairs, a joint European uranium enrichment project was in the U.S. interest if it brought the United Kingdom closer to the European Communities, and it was also “inevitable.” If, however, it was postponed, “we might witness at a later stage, the establishment of an independent German facility.” Preventing such an outcome would be an important consideration in further U.S. discussions of the tripartite project.52

Proposals to “prevent, delay, or limit” European enrichment projects remained on the AEC agenda, although some thought that an accepting approach could be beneficial. A more immediate challenge was a clear shift in the British approach to secrecy. Despite the unambiguous position in favor of the classification arrangements that Washington had been taking, the British wanted to phase them out. On 22 October 1968, British Embassy Minister Edward Tomkins delivered an aide-mémoire arguing that when plans to build a centrifuge plant become known, governments in Western Europe, South Asia, and the Western Pacific would conclude that the “centrifugal method [of uranium separation] is within their technological and economic grasp.” Although the British believed that secrecy had created a “valuable breathing space for eight years” and had kept the gas centrifuge from proliferating, it was no longer serving a “useful purpose.”53

With other countries interested in the technology, the British said they did not want to be the “dog in the manger” by denying them aid. Moreover, classification “may be difficult to reconcile” with the NPT because of its provisions for sharing “benefits of peaceful applications of nuclear technology.” If widespread development of centrifuge technology was “inevitable,” the best thing for the UK and United States to do was to engage in unclassified “technical collaboration” with interested countries to ensure that future plants “were not put to undesirable uses.” Their business plan for the tripartite project apparently assumed significant commercial opportunities in widespread dissemination, because they wrote that the “ultimate objective of collaboration … would be to produce centrifuges and perhaps jointly build and operate centrifuge plants” for peaceful uses. Once the technology was made widely available, it would be unrealistic “to imagine that [it] could remain classified.” With these commercial goals in mind, the British wanted to discuss the possibility of declassification in a few years.

U.S. officials would have none of this. The U.S. government's response to the British, representing a consensus at the AEC, ACDA, and the State Department, upheld the existing system. On 13 November 1968, Deputy Assistant Secretary of State for Politico-Military Affairs Philip J. Farley handed over a paper that acknowledged the British point that a gas centrifuge project would significantly increase the interest of other countries in the technology. What worried the U.S. government was that declassification might “[aggravate] the problem of nuclear weapons proliferation.” As for the argument that the NPT made necessary the declassification of the gas centrifuge, the United States “does not believe that [it] should be construed as obliging an action that could aggravate the very problem that the Treaty is directed against.” Moreover, because the treaty was “not yet in effect,” the declassification of sensitive nuclear technology would be premature. With such countries as Brazil and India refusing to sign the NPT, U.S. officials may have assumed that secrecy and controls were all the more necessary because those countries would likely not participate in a comprehensive safeguards system.54

The United States agreed to more discussions in early December 1968 of the classification issue as well as the implications of the U.S.-UK Civil Uses Agreement. In the U.S. view, if the British intended to share gas centrifuge R&D with the Dutch and FRG, they could not include “restricted data” received from the United States earlier in the decade, without approval. Indeed, according to a State Department lawyer, approval was not enough, because under Article IX (c) restricted data could not be transferred without corresponding U.S. cooperation agreements with the Dutch and West Germans—agreements that did not exist.55

Seeing the early December talks partly as a way to elicit intelligence on the status of European gas centrifuge programs, AEC officials acquired some general information: The Dutch project may have been more advanced than the British program and certainly more advanced than the FRG's, but the British had the most experience in handling uranium hexafluoride, the chemical form of uranium used in the enrichment process.56 But the discussions did not make any headway on secrecy issues. Indeed, the British suggested that once the tripartite project was under way, “gradual declassification” would be necessary to facilitate contracts with suppliers of equipment. Insisting that secrecy was necessary until there was “universal adherence” to the NPT and IAEA safeguards, the U.S. team authorized the British to relay its thinking to the Dutch and West Germans on a confidential basis.57

So far as can be told, the British dropped their declassification proposals, perhaps to avoid a disagreement that could turn Washington against the tripartite scheme. The two sides did not agree on the status of U.S. restricted data. U.S. officials wanted to know whether the British intended to share any such data with the Dutch and West Germans. The British emphasized that they would not. Senior UK Atomic Energy Authority official David Pierson acknowledged the possibility of identifying “some directly ‘derived’ features” from the exchanges with United States but that it would be difficult to isolate them. In any event, he believed that Article IX of the Civil Uses Agreement did not necessarily require one of the two parties to approve the transfer of information.58

From the U.S. perspective, this posed a difficult problem. The powerful Joint Committee on Atomic Energy (JCAE) had played a major role supervising the negotiations of Article IX and would insist on strict adherence. The British gave Washington a note declaring they would not transfer restricted data to their partners and requesting a U.S. “green light.” Sticking to their story that “they derived very little” from the exchanges, the British argued that without a “favorable” U.S. response they would face a “calamitous” situation: They would be unable to share technology with the Dutch and West Germans.59

The Nixon Administration and the Tripartite Project

French opposition forced the incoming Nixon administration to focus on the tripartite project. Nixon had made a postelection statement favoring ratification of the NPT, but privately he and his national security adviser, Henry Kissinger, were ambivalent, even critical, about the treaty. French opposition compelled Nixon and Kissinger to think more deeply about nonproliferation goals and the value of the tripartite project in that connection. Although some AEC officials remained worried about the project and wanted to find ways to delay it, the White House and the State Department saw important political and nonproliferation benefits and did not want to interfere. Nevertheless, the State Department had to get involved to prevent a crisis in relations with London caused by the AEC's determination to clamp down on all U.S restricted data that might be embedded in the British gas centrifuge model and transferred to the Dutch and West Germans.

Nixon may have heard about the gas centrifuge issue for the first time during his European trip in February 1969 when he met with Prime Minister Harold Wilson. The latter tried to make Nixon aware of the proliferation implications, the importance of the tripartite project, and the problem of restricted data transfers under Article IX of the Civil Uses Agreement. Although the Nixon White House would become known for its interest in putting U.S. government uranium enrichment operations on a businesslike basis, the president gave no indication that he was familiar with any of those issues.60

A few weeks later, clear and distinct opposition to the tripartite plan from French President Charles de Gaulle compelled Nixon and Kissinger to take a position. Before Nixon came to power, the State Department and other agencies were aware that the French strongly disliked and were even “angry” about the tripartite scheme, in part because of West German participation, but also because of its negative implications for French interest in “commercializing” their capability to enrich uranium with their gas diffusion plant.61

De Gaulle brought those concerns to a higher level. Meeting with Nixon on 20 March 1969, Jacques Chaban-Delmas, the president of the French National Assembly, delivered an “oral message” from de Gaulle. Determined to keep Britain out of the EC and probably to hinder the tripartite project, de Gaulle opposed British involvement—a “devious game”—with West Germany. Consistent with his long-standing policy of trying to contain West German power, he emphasized the risk of a West German nuclear weapons program. Despite the FRG's professed non-weapons intentions, “governments can change” and “serious complications” could ensue.62

Nixon greatly admired de Gaulle, but that did not stop him from challenging a central point. Agreeing that the West German nuclear issue was a “sensitive problem,” Nixon told Chaban-Delmas that the FRG was “denied” nuclear weapons for “evident and unavoidable reasons,” but the current government was a “responsible one” and it was necessary to take into account its “interests … in the area of peaceful uses of atomic energy.”

For the formal reply to de Gaulle, Kissinger recommended the “hands-off” approach the State Department had been taking since 1968. Noting that the project incorporated nonproliferation commitments, that it was a “good way to encourage UK-continental cooperation,” and that it was “a purely European matter,” Kissinger advised that “we … find a way to tell the French that this project cannot be interfered with by us,” and certainly not on the grounds “worrying” them. As he put it, “for somewhat the same reasons that concern the French we much prefer to see the Germans involved with the British and Dutch,” thereby avoiding a solitary FRG nuclear enrichment project. Kissinger did not want to risk unnecessary friction with key allies, especially Bonn and London, to appease de Gaulle. Kissinger did not mention AEC interest in an enrichment monopoly, perhaps because he saw this as of marginal importance.63

Nixon agreed, and a White House message to de Gaulle sent on 29 March 1969 tactfully turned aside the objections: The tripartite project was acceptable because it would be “placed under the safeguards provided in the NPT.” Moreover, because the “European governments involved want the project … as long as it was properly safeguarded against use for weapons purposes, we should not oppose it.” When de Gaulle saw the message is not clear, but a meeting with Nixon on 31 March on the occasion of Eisenhower's funeral gave the French president another opportunity to convey his anxieties. Nixon took the initiative by voicing concern over “tension” between France and the FRG, which was of interest to Washington because of its broader implications. De Gaulle acknowledged that French-West German relations were “close and numerous,” but he also observed that West Germany's “driving ambition … had led to bitter experience” since the 1870 Franco-Prussian War. Memories of aggression and occupation shaped France's determination that “the Germans not possess their own nuclear weapons,” and he had “told them so.” This made the tripartite scheme “irritat[ing]” because of what uranium enrichment meant for a nuclear capability.64

Nixon apparently had no more to say to de Gaulle on the matter, but other French inquiries produced a White House statement that guided the agencies. Washington would not oppose the project, because the participants saw it in their interests. Moreover, the project's “multinational” character offered “the best” assurance that European nuclear power would develop on a “non-discriminatory” basis affording “maximum assurances regard to the non-proliferation of nuclear weapons.” State Department officials interpreted this as a “benevolent overall attitude.”65

Members of France's Atomic Energy Commission complained to Seaborg but to no avail. Despite initial ambivalence, he took the White House–State Department position. Seaborg had seen the tripartite scheme as a “vexing” problem because any new overseas development of uranium enrichment capabilities posed a “contingent proliferation risk.” Nevertheless, as he explained to Ambassador to NATO Robert Ellsworth, “on the whole … we shouldn't oppose [it] and that it probably had advantages”; for example, it would be a way to “keep an eye on West German progress.” Moreover, the Dutch could “insist” that the FRG sign the NPT and ensure that the IAEA safeguard West German facilities. Therefore, instead of increasing “the possibilities for proliferation the tripartite arrangement might in fact decrease the possibilities.”66 Seaborg, however, did not control the AEC and had to consider the views of others on the commission.67

As the tripartite negotiations proceeded, the problem of restricted data transfer under Article IX still cast its shadow. Whether the British could transfer U.S. restricted data to their partners would produce difficult moments because some AEC officials and leading members of the JCAE zealously sought to protect U.S. legal rights as they understood them. Yet, the approach the White House had taken during the debate with de Gaulle became a template for top-level policy during this controversy. The value that top State Department officials and Seaborg saw in the tripartite proposal made them unwilling to allow a dispute over outmoded restricted data to harm Anglo-American relations.

From Seaborg's perspective, any U.S. information the British were using in their gas centrifuge R&D was obsolete. His view was not controlling, and some Commissioners and members of the JCAE, especially its chairman, California Democrat Representative Chet Hollifield, pressed the issue, making the British worry that Washington would “[pull] the rug out from under them” by blocking information exchanges with the Dutch and West Germans. To save the project, the UK sought to resolve the issue quickly and engaged Washington in protracted talks.68

A key moment occurred in early March 1969, when a U.S. AEC–State Department team saw the British gas centrifuge blueprints. Although they had “argued to a standstill” over whether the British machine incorporated U.S. restricted data, the AEC officials were relieved to see “key bits of information which exposed the primitive nature of their machine.” According to a State Department official account, “our experts referred to the British machine as a ‘model T’” and “no longer feared any real competition in the fuel enrichment business from the tripartite collaboration for the next four or five years.” That advantage and the clear nonproliferation benefits convinced State Department officials of the merits of the “non-obstructionist” approach.69

Initially refusing to let U.S. experts inspect their machine to protect commercial secrets, the British insisted that the AEC had provided them with only “general information.” To the surprise of Wilson's chief scientific adviser, Sir Solly Zuckerman, who had been assured that the U.S. input was minimal, further investigation revealed that their production model embodied U.S. restricted data, especially a “dished” end-cap (intended to prevent a spinning centrifuge from warping). The British acknowledged this influence to the State Department and argued that U.S. approval of the technology transfer was essential lest the whole tripartite project be put at risk. According to the Foreign Office, if Washington “made use of a technicality to block the establishment of an independent European enrichment capacity,” it would be “as embarrassing for the United States as it would be for us.”70

Secretary of State William Rogers and his deputies did not want to let the restricted data problem cause a crisis in relations with the UK. Believing that the British were acting in good faith, Under Secretary of State for Political Affairs U. Alexis Johnson told Seaborg that the department did not want to be “in the position of blocking” the project and emphasized the importance of British assurances that transfer would not be a “precedent.” Seaborg was receptive and wanted to find a “little spot of light between the cracks.” But he also needed to avoid a “blow-up” with Commissioner James Ramey, who had insisted on an inspection of the British production model despite London's view, relayed by Zukerman, that such action would be “inequitable.” Zuckerman's promise that he would try to persuade British authorities to allow U.S. experts to look at the British centrifuge suggested that a mutual understanding was possible.71

After Zuckerman persuaded the British Atomic Energy Authority that U.S. access was crucial, a team of AEC and State Department officials traveled to Capenhurst in mid-July and inspected the production model (but not cascades or an entire plant). The U.S. team found that the British model's end-cap incorporated some U.S. technology, but as Seaborg observed, “the extent of this is so small that we would not be able to resolve the issue.” The inspection confirmed the initial impression that the British “Model T” was not a near-term commercial threat but also sparked the AEC's realization that denying the British the opportunity to share their production model with their partners might spur the FRG and the Netherlands to design a better machine. Realizing that no significant secrets were at issue, AEC officials recognized that if they obstructed the tripartite scheme it would damage relations with London and make it more difficult for Bonn to adhere to the NPT.72

London and Washington avoided further controversy by agreeing to disagree. In an aide-mémoire, the British argued that their centrifuge was “largely developed through independent research” and that the end-cap was a side issue because “known engineering principles” would have brought them to that solution. Therefore, Article IX (c) did not preclude them from sharing technology with the Dutch and West Germans. Nevertheless, the British assured U.S. officials that they would not set a precedent and would “fully [inform]” the U.S. if future exchanges with their partners raised issues of restricted data transfers. In its reply, the AEC rejected the argument that classified information could be transferred “on the basis of the recipient's belief as to its importance or its degree of originality.” The hardline JCAE was not satisfied and successfully insisted that the U.S. reply “slap the British wrist” by expressing “displeasure” over the proposed retransfer of U.S. restricted data. Thus, to find “light between the cracks,” Washington interpreted the law flexibly: it could not approve the retransfer but would not try to stop it. In light of British assurances, the United States would “not object in this instance.”73

Tripartite Classification and Security Arrangements

As it turned out, the controversy over the transfer of classified U.S. data did not cause the delays in the tripartite talks or exchanges of data feared by the British. As U.S. diplomats (who closely monitored developments) learned in 1969, the three partners were slow to conclude an agreement because of differences over the location of the headquarters and over the British government's leeway to produce weapons-grade uranium using centrifuges “growing out of their cooperation” with their European partners. The latter was of particular concern to the Dutch because of domestic political pressures, but they also wanted the central office to be in the Netherlands. The Dutch finally accepted a headquarters in London once the others agreed that the Netherlands would host an enrichment plant. By the end of 1969, with these problems resolved, the three governments signed a ministerial-level agreement.74

No controversy was reported over secrecy policy. At an early meeting, the partners agreed that any changes in classification procedures “would have to be worked out in agreement” with Washington. Under agreed arrangements, a tripartite joint committee would have responsibility for such matters as safeguards, supervision of classification arrangements, and security procedures. According to the British, security procedures were to be described in a “confidential agreed minute” and would generally correspond to NATO regulations. Among the explicit provisions was “positive vetting” for individuals who were to receive secret information. This was all in accordance with U.S. preferences.75

As the negotiations reached their conclusion, the British told U.S. diplomats that they “have gotten the Germans and Dutch to agree to special security procedures” that would be “compatible with NATO/ATOMAL procedures” approved by NATO ministers in June 1964. That would mean, among other things, that getting access to information on gas centrifuge technology would require a need-to-know and a special clearance for nuclear data based on a background investigation and a periodic review of clearances. The three governments provided the State Department with documentation on the security arrangements, but the degree to which they provided for ATOMAL-type procedures is not clear. Whatever the details, gas centrifuge classification in Western Europe was on an ostensibly firmer footing, replacing informal arrangements with a formal agreement that created a framework for the information sharing needed to develop new centrifuge models. Nonproliferation and commercial objectives had overtaken any doubts that the Dutch, West Germans, and British intermittently had about the merits of secrecy.76

The necessities of creating a complex industrial operation, including the creation of special management companies and prime contractors to build centrifuges and operate enrichment plants, as well as the hiring of a growing number of employees, led the members of the tripartite project to ask Washington, in late 1971, for additional “classification relief.” Although the three governments agreed that security was “indispensable” to protect the technology, they also believed that significant aspects of procurement operations, such as the purchase of “conventional” materials and components (e.g., computers, electrical transformers, and containers for uranium gases) could be declassified, as could cost details. Influencing the request were the large number of employees directly or indirectly connected with the project, which made the protection of all documents at the “highest level of classification” impractical and could lead to an undesirable “dispersal of security effort.” Such considerations meant that the 1960 classification guide was “no longer appropriate” because it had classified “virtually all centrifuge technology” as secret.77

As before, AEC officials believed that secrecy controls for the gas centrifuge were valid and necessary for “buy[ing] time in minimizing the proliferation problem” until a global safeguards system was in place. All the same, they recognized that the tripartite project faced problems that required changes in the degree of classification. What was important was that the interested parties took “all deliberate caution” before changing any of the classification rules. For example, AEC experts saw a danger that equipment orders and re-orders could include “specifications which … would reveal technology that should remain classified.”78

To reach agreement on new guidelines, the four governments met at The Hague in May 1972. Prior to the meeting, the AEC sent the three governments a draft classification guide that was designed to accommodate their desire for “classification relief.” As in the 1960 guide, key topics were to remain classified, such as design information for individual centrifuge units, arrangements for production cascades, and plant operations. New sections on financial data and procurement indicated an attempt to determine what aspects of those topics could be unclassified, including certain unspecified components. The discussants agreed that the tripartite group would revise the U.S. draft and return it, which they did in early 1973. In August the AEC accepted the tripartite classification guide and produced a parallel document for directing U.S. classification decisions.79

Deflecting the Tripartite Project?

The AEC and the URENCO partners found common ground in updating the classification manual, but during the preceding years, 1969–1971, Washington made an unsuccessful indirect attempt to counter the tripartite project by offering to share alternative uranium enrichment technology.80 Seaborg saw positive features in the tripartite project, but he and the AEC perceived a proliferation risk in any overseas gas centrifuge project, especially one with “export ambitions.” Also troubling AEC officials was the possibility that new enrichment production capacity overseas could hurt the U.S. balance of payments by reducing earnings from reactor fuel sales. Realizing, however, that Washington could not be “entirely aloof” from European enrichment activities, the AEC proposed to minimize proliferation hazards and financial losses by sharing (selling) classified gaseous diffusion technology, on a classified basis and under appropriate safeguards, with Western Europe and possibly other countries, including Australia and Canada.

The AEC was in no hurry to share the technology and sought to defer transferring classified information “as long as possible.” Moreover, to prevent excess production capacity, the Commission was “interested in avoiding the construction of large increments of new capacity until our own existing facilities are more fully utilized,” by around 1980. Such self-interested conditions were not likely to have great appeal in Western Europe, where key policymakers sought to move quickly in developing enrichment production capacity.81

Beginning in mid-1969, when the negotiations over restricted data transfers were unfolding, Seaborg began lobbying within the administration for uranium enrichment technology sharing. In a letter to Secretary of State Rogers, Seaborg pointed to the emergence of the tripartite project and the pressures created by the NPT for the sharing of enrichment technology with the non–nuclear weapons states. He suggested that by “constructively associating itself with prospective foreign developments” through a gaseous diffusion sharing arrangement, Washington might be able to ensure that overseas enrichment projects developed in ways that were “compatible with US national security, economic, and political interests.” The implication was that even if the United States lost its monopoly position it could gain in other ways through an accommodation with European competitors.82

A few weeks later, in June 1969, during an AEC-ACDA-State Department discussion of these ideas, the attendees highlighted the explicit purpose of the AEC proposal: to “deflect … major investments in gas centrifuge facilities” by sharing gaseous diffusion technology, an area in which Washington had distinct technological advantages. AEC Commissioners Theos Johnson and James Ramey ruled out the idea of including gas centrifuge technology in an offer on the grounds of “commercial advantage” and national security, although some at the meeting doubted that the Europeans would accept those excuses.83

The proposal gained momentum, but some significant figures did not object to sharing the gas centrifuge. J. Robert Schaetzel, the U.S. ambassador to the European Community, argued that Washington should “keep its option[s] open” with a fallback offer of gas centrifuge technology. Motivating his proposal was a mixture of considerations: “nothing will stop” the tripartite project, sharing enrichment technology information would help the Europeans make long-term decisions on the comparative advantages of both processes, and cooperation on a centrifuge project would “insure that adequate safeguards” are applied and counteract European perceptions that a gaseous diffusion offer was a “diversionary effort designed to scuttle” the tripartite project. A U.S. offer of gaseous diffusion technology would be more “credible” if Washington made clear that cooperation on the gas centrifuge would be possible if it proved to be the more competitive technology.84

NSC staffers, who played a key role in developing the proposal, considered offering both technologies but decided in favor of gaseous diffusion only. During a February 1970 discussion of the recommendations to Nixon, Seaborg argued that gaseous diffusion technology had important cost advantages and that its proliferation risk was less than the gas centrifuge. Moreover, Washington would have a “voice” in the direction of a cooperative enrichment project. Because the AEC wanted to modernize and expand U.S. enrichment production capacity, Seaborg stressed the importance of reaching agreements with the Europeans on the timing of projects in order to “preserve our market as long as possible.” Technology sharing, Seaborg observed, might delay the European gas centrifuge project by five to ten or “more” years, which Under Secretary of State Elliott Richardson believed was “a very important interval in today's world.” Yet, Seaborg and his colleagues recognized that Washington could not keep the gas centrifuge process bottled up indefinitely if other countries, including India, were willing to accept nonproliferation rules and to keep the technology classified.85

Before Kissinger made any recommendations to Nixon, he asked the agencies for more study of the pros and cons of gas centrifuge versus gaseous diffusion, but the resulting June 1970 analysis emphasized the centrifuge's unique proliferation risks, among other disadvantages.86 Kissinger was not entirely persuaded, however, and when he advised Nixon to sign off on the proposal to share gaseous diffusion technology, he suggested that an offer of gas centrifuge technology could be a “good bargaining counter” at a later stage of negotiations. He further believed that the Europeans would not accept any effort by Washington to involve itself in the management of a multinational European enrichment facility. Therefore, Kissinger directed the agencies to avoid making the case to the JCAE that sharing the technology was a means of “impeding” gas centrifuge development or that Washington would have a guiding role in a European project. As far as he was concerned, the European gas centrifuge project was an “ongoing program and would probably not be curtailed by an offer to share diffusion technology unless the economics of the diffusion technology were markedly more advantageous.” Tacitly the proposal would have to be sold to the JCAE on such merits as maintaining U.S. leadership in the uranium enrichment field, ensuring that overseas enrichment activities were safeguarded, and securing income from royalties and the export trade associated with the transfer of gaseous diffusion technology.87

For political reasons, an offer of technology sharing needed the approval of the JCAE before it could be presented to other countries, but the committee was at loggerheads with the White House over whether appropriated funds should be available to the Cascade Improvement Program (CIP) to expand gaseous diffusion production capacity. From the White House's perspective, European acceptance of the U.S. offer would enable Washington to avoid costly investments in the CIP, to further study the gas centrifuge's potential, and to move ahead in privatizing uranium enrichment operations. Complicating matters was Alexis Johnson's support for investments to expand enrichment capacity, which put him on the side of the JCAE.88 Kissinger sided with Johnson and the State Department and sought to get the CIP funds released, but the disagreement produced months of delay and greater European interest in undertaking their own projects, especially in light of rising U.S. reactor fuel prices and prospective shortages of U.S. production capacity.89

Nixon broke the impasse by releasing funds for the CIP in June 1971, and the skeptical JCAE finally approved the gaseous diffusion proposal, permitting the AEC to hold a conference on it in Washington, DC, in November 1971. The offer came with preconditions, however. In keeping with the JCAE's insistence on protecting the secrecy of U.S. enrichment technology and the strongly protectionist elements in the AEC who also favored stringent conditions, the U.S. plan stipulated that before Washington shared any classified information, the Europeans would have to commit to the construction of a “facility on a time schedule and of a scale which would be of interest to the United States.” John Runnalls, a Canadian government nuclear energy expert who attended the conference, observed that the U.S. offer produced a “stalemate”: The Europeans would not make assurances without more information from the AEC, but the latter would not provide it without a commitment. Runnalls had the impression that “many” in the U.S. government really did not want to “see foreign projects carried out”. He found this surprising because he had assumed that Washington wanted to build overseas gaseous diffusion plants to “discourage [the] adoption” of the gas centrifuge. Secrecy and AEC organizational interests had nullified the proliferation concerns that had originally shaped the initiative.90

The U.S. offer generated little serious interest, and only the Canadians continued the discussions. According to a State Department report, complicating serious consideration of the offer was skepticism in Western Europe that it was “made in good faith” and suspicion that it was a ploy to “slow down the pace of enrichment technology.” Moreover, the U.S. government itself did not pursue its offer “diligently.” The Washington bureaucracy could not develop a credible proposal to share enrichment technology, much less reduce interest in the gas centrifuge. By 1975, URENCO, was producing and selling low-enriched uranium, and developments during 1973 and 1974, notably the AEC's tougher terms for enrichment service contracts and the suspension of long-term reactor fuel supply agreements, encouraged new enrichment projects, such as France's EURODIF.91 By then, in the wake of India's “peaceful nuclear explosion” in May 1974, the nuclear proliferation problem had broadened in scope, and Washington was seeking help from allies to regulate exports of sensitive nuclear technologies.

Establishing Safeguards

Despite doubts about the European gas centrifuge project, the AEC worked easily enough with the three governments in trying to establish IAEA safeguards for the uranium enrichment plant at Almelo in the Netherlands. This would be the first such facility subjected to international inspection and as such would be an important test of the safeguards system that U.S. officials saw as essential for an effective nonproliferation policy.

AEC officials still worried about inspectors collecting intelligence on classified processes, but so did the URENCO partners (despite earlier British interest in declassification). ACDA had proposed giving inspectors the right to “walkthroughs” of the interior of centrifuge plants, but the more distrustful AEC saw that as a proliferation risk because inspectors would have greater access to sensitive technology, thereby potentially undermining the classification system. Although both safeguards and classification were anti-proliferation measures, the suspicious AEC believed that in the short-term an intrusive inspection could pose a greater proliferation danger “than any encumbrances that the absence of a walkthrough would place on an IAEA inspector.” The AEC, however, recognized that the indefinite classification of a “commercial process” was not possible and that in the “long term … safeguards rather than classification are likely to be more effective protection against the illicit use of enrichment facilities.”92

In 1972, Washington and the URENCO partners saw eye-to-eye on what kind of inspection was permissible. The AEC, which wanted to limit inspections to the inside of the plant's perimeter and the building's exterior, found acceptable the Dutch position that centrifuge cascades should be “screened from view.” Inspection systems could measure the composition of uranium entering and exiting the plant, survey vehicles and persons entering and exiting, and confirm the contents of uranium gas cylinders in nearby storage areas. The AEC believed that such procedures would provide “adequate” though “not foolproof assurance” against the possibility of secret diversions, which URENCO's multilateral controls should minimize. Within those limits, AEC officials believed that Washington should “assure that the level of IAEA inspection … be sufficiently intense to permit continuous surveillance.”93

The safeguards discussions that followed the talks on classification in May 1972 confirmed the mutual understanding on non-access areas in centrifuge plants. That did not settle matters, however, because the Almelo plant fell within the scope of the European Atomic Community, which under NPT Article III would negotiate safeguards with the IAEA. That requirement posed a complex problem because the EURATOM treaty required openness, and the Almelo management refused to let inspectors into the plant. IAEA officials were themselves divided over the validity of a non-access area or whether it could be properly safeguarded, but they accepted it as a working hypothesis for further study. Negotiations over a “facility attachment” spelling out safeguard procedures dragged on, but details are scarce because IAEA archival records on safeguards are closed. Apparently, not until the mid-1980s was an agreement reached, with the “facility attachment” stipulating “walkthroughs” in the cascades area, among other arrangements. Either the URENCO partners gave in to EURATOM, or they, along with the AEC's successors at the U.S. Department of Energy, decided that nonproliferation goals would be better served by giving inspectors access to Almelo's inner sanctum.94

In May 1972, when U.S. and tripartite officials were meeting in The Hague to update the classification guide and to discuss safeguards for Almelo, an event in the Netherlands demonstrated that commitments to secrecy were only as good as the security arrangements that supported them. A. Q. Khan, a Pakistani with a recent Ph.D. in metallurgy, started a job with a URENCO subcontractor. He soon received access to sensitive and secret information about the gas centrifuge process because of a defective security investigation—Khan's (false) claim that his wife was a Dutch citizen was not investigated—and despite his having only a low-level non-secret clearance. In a hurry to get production going, the plant management apparently cut corners to acquire a skilled workforce. By 1974, not long after India's nuclear test, Khan was spying to aid the Pakistani weapons program. The system that had kept gas centrifuge technology under security wraps had failed.95

Thus, even before the proliferation risk inhering in the gas centrifuge had been fully grasped, the feared scenario came to pass—the technology had leaked and a determined proliferant was building a clandestine enrichment plant. The ATOMAL procedures, or their improper application, had not prevented an act of espionage. When knowledge of Khan's espionage spread some years later, those AEC officials who had seen proliferation risks in tripartite information sharing may have concluded that they had been correct. In any event, U.S. officials remained committed to preserving secrecy for the gas centrifuge and sought to extend it to new enrichment technologies.96


The AEC's finding that the latest developments in gas centrifuge technology posed a significant nuclear proliferation risk created new requirements for U.S. diplomacy and security policy. Determined to minimize such risks, officials in the Eisenhower administration and its successors realized that they needed the help of allies to establish government secrecy and export controls to “retard” the application of the gas centrifuge process by would-be nuclear weapons states. Even though the technology was not yet operational, the Netherlands, the UK, and the FRG participated in the “gentlemen's agreement” that Washington had sought. The Japanese did not agree to apply state secrecy but followed business secrecy procedures to limit the dissemination of gas centrifuge information.

The FRG and the Netherlands were apparently “reluctant partners” in the classification system, but they, along with the British, remained basically cooperative. An exception was in 1968 when the British tried to convince Washington to relax secrecy, but senior U.S. officials saw that as inconsistent with the basic goals of the newly signed NPT. The British hoped that reduced secrecy could facilitate the tripartite gas centrifuge project, but Washington's support depended on preserving the classification agreement. The AEC worried about the tripartite project's implications for the U.S. position in world reactor fuel markets and nonproliferation policy. The “benevolent” U.S. stance, however, was overriding partly because the project would minimize the danger of an independent West German enrichment facility, despite de Gaulle's apprehensions. The AEC complicated matters, though without undermining the project, by taking a tough position on British plans to transfer U.S. “restricted” centrifuge data to its continental partners.

Seeing a proliferation and a competitive risk, the AEC's interest in finding ways to delay the URENCO project found some traction in the Nixon administration, suggesting limits to “benevolence.” Yet, the U.S. proposal to share gaseous diffusion technology had so many restrictions that it never found traction among dubious West European governments, which in any event were determined to undertake their own enrichment projects. AEC thinking about the importance of secrecy in limiting IAEA oversight of enrichment plants was in harmony with the URENCO partners, but in the long run the narrow secrecy agenda did not bar inspectors from full access to the Almelo plant.

When U.S. officials took initiatives to persuade allies to accept secrecy and controls over gas centrifuge technology, they saw such measures as short-term solutions pending the global application of safeguards. Temporary measures became more enduring elements of the nonproliferation system that developed in the 1960s and the years that followed. Nevertheless, senior U.S. officials and policy experts understood that the gas centrifuge was not so technologically recondite that controls could prevent determined s countries from developing it. Such figures as Seaborg and McNamara as well as midlevel AEC experts believed it was possible only to “buy time” and impose “maximum delay” on efforts to enrich uranium by would-be proliferants.

Even when countries such as Pakistan acquired stolen gas centrifuge information, the United States and its allies tried to limit the technology's application by restricting access to critical systems, although that did not prevent Islamabad from building the bomb. According to a recent study, supply-side controls can “make the task of building and operating centrifuges more arduous” and limit the “ability to states to build high-performance centrifuges.”97 In addition, the 2015 agreement on Iran illustrates the role IAEA safeguards can play in monitoring, even curtailing, a gas centrifuge program. To the extent that secrecy and other controls have had such an impact, Seaborg and McNamara, among others, may have concluded that their policy of “retardation” had been reasonably successful on its own terms.98


An earlier version of this article was presented at a panel on “A Global History of Nuclear Non-Proliferation: The Beginnings, 1955–1976,” during the American Historical Association's annual meeting, New Orleans, January 2013. Thanks to the JCWS's anonymous readers for their helpful suggestions, and to Lynn Eden, Francis J. Gavin, Elmar Hellendorn, John Krige, and Susanna Schrafstetter for their astute comments at various stages of the writing.



U.S. Atomic Energy Commission, “Summary Notes of Briefing on Gas Centrifuge, Thursday, June 30, 1966,” 27 July 1966, in Library of Congress (LOC), Glenn Seaborg Papers, Box 638, Summary Notes of Meetings June–Oct. 1966.


On historical memories and the West German nuclear problem, see Susanna Schrafstetter, “The Long Shadows of the Past: History, Memory and the Debate over West Germany's Nuclear Status, 1954–1969,” History and Memory, Vol. 16, No. 1 (2004), pp. 118–145.


For some of the recent work, see Susanna Schrafstetter and Stephen Twigge, Avoiding Armageddon: Europe, the United States, and the Struggle for Nuclear Non-Proliferation, 1945–1970 (Westport, CT: Praeger, 2004); Sean Maddock, Nuclear Apartheid: The Quest for American Atomic Supremacy from World War II to the Present (Chapel Hill: University of North Carolina Press, 2010); Avner Cohen, The Worst Kept Secret: Israel's Bargain with the Bomb (New York: Columbia University Press, 2010); Roland Popp and Andreas Wenger, eds., “Special Issue: The Origins of the Nuclear Nonproliferation Regime,” International History Review, Vol. 36, No. 2 (2014), pp. 195–362; and “Nonproliferation and Proliferation: Strategies and Outcomes,” Special Issue, International Security, Vol. 40, No. 1 (Summer 2015), pp. 9–119, as well as the website of the Nuclear Proliferation International History Project at the Woodrow Wilson Center for International Scholars.


See Susanna Schrafstetter and Stephen Twigge, “Spinning into Europe: Britain, West Germany, and the Netherlands—Uranium Enrichment and the Development of the Gas Centrifuge, 1964–1970,” Contemporary European History, Vol. 11, No. 2 (2002), pp. 253–272; John Krige, “U.S. Technological Superiority and the Special Nuclear Relationship: Contrasting British and American Policies for Controlling the Proliferation of Gas Centrifuge Enrichment,” International History Review, Vol. 36, No. 2 (2014), pp. 230–251; John Krige, “Hybrid Knowledge: The Transnational Co-production of the Gas Centrifuge for Uranium Enrichment in the 1960s,” The British Journal for the History of Science, Vol. 45, No. 3 (2012), pp. 337–352; John Krige, “The Proliferation Risks of Gas Centrifuge Enrichment at the Dawn of the NPT: Shedding Light on the Negotiating History,” The Nonproliferation Review, Vol. 19, No. 2 (2012): 219–227; Stephen Twigge, “A Baffling Experience: Technology Transfer, Anglo-American Nuclear Relations, and the Development of the Gas Centrifuge 1964–70,” History and Technology, Vol. 19, No. 2 (2003), pp. 151-163; William Burr, “The ‘Labors of Atlas, Sisyphus or Hercules’? U.S. Gas Centrifuge Policy and Diplomacy, 1954–1960,” International History Review, Vol. 37, No. 3 (2015), pp. 431–457; and R. Scott Kemp, "The Nonproliferation Emperor Has No Clothes: The Gas Centrifuge, Supply-Side Controls, and the Future of Nuclear Proliferation,” International Security, Vol. 38, No. 4 (Spring 2014), pp. 39–78.


Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” pp. 241–242; and Kemp, “The Nonproliferation Emperor Has No Clothes,” pp. 39–78. In this essay, Kemp expertly surveys the world-wide development of gas centrifuge technology but overstates the degree to which U.S. officials have seen supply side controls as the solution.


For an extraordinary new contribution on Dutch policy toward the gas centrifuge, among other issues, see Elmar Hellendoorn, “Between the Devil and the Deep Blue Sea: The Netherlands and the Struggle for Nuclear Order, 1954–1966,” PhD diss., Utrecht University, 2016.


R. Scott Kemp, “The End of Manhattan: How the Gas Centrifuge Changed the Quest for Nuclear Weapons,”’ Technology and Culture, Vol. 53, No. 2 (2012), pp. 272–305; Houston Wood et al., “The Gas Centrifuge and Nuclear Weapons Proliferation,” Physics Today, Vol. 61, No. 9 (2008), pp. 40–45, and R. Scott Kemp, “Gas Centrifuge Theory and Development: A Review of U.S. Programs,” Science and Global Security, Vol. 17, No. 1 (2009), pp. 2–3; Oak Ridge National Laboratory, “Assessment of a Control System: Detection of Hidden Isotope Separation Facilities,” 10 April 1961, Department of Energy Mandatory Declassification Review (MDR) Release.


Burr, “The ‘Labors of Atlas, Sisyphus or Hercules’?” pp. 431–457.


For intelligence estimates of proliferation risks during the 1960s, see, for example, National Intelligence Estimate (NIE) 4-63, “Likelihood and Consequences of a Proliferation of Nuclear Weapons Systems,” 28 June 1963, CIA MDR release (copy on file at National Security Archive, as with all MDR release cited herein); and NIE 4-2-64, “Prospects for a Proliferation of Nuclear Weapons over the Next Decade,” 21 October 1964, CIA MDR release.


On the history of nuclear secrecy, see Alex Wellerstein, “Knowledge and the Bomb,” Ph.D. diss., Harvard University, 2010.


Mary Nolan, “Rethinking Trans-Atlantic Relations in the First Cold War Decades,” Bulletin of the German Historical Institute, Suppl. 10 (2014), pp. 19–38; Telegram 4560, U.S. Embassy Bonn to State Department, “Gas Centrifuge,” 8 April 1969, in National Archives and Records Administration (NARA), Record Group (RG) 59, Department of State Records, Subject-Numeric Files 1967–1969 (SN 67–69), AE 11-1.


A. A. Wells to Walter G. Whitman, “UK Centrifuge Information,” 20 June 1962, in NARA, RG 59, Bureau of Scientific and Technological Affairs, Central Files, 1964–1966, Box 5, Centrifuge July 1960–May 1963; Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” p. 234, and “Hybrid Knowledge,” pp. 343–344.


Memorandum of conversation (Memorandum of Conversation), “Classification of Centrifuge Project,” 12 October 1960, in NARA, RG 59, Bureau of European Affairs, Office of Atlantic Political and Economic Affairs, Records Relating to Atomic Energy Matters, 1960–1963, Box 2, Centrifuge; Hellendoorn, “Between the Devil and the Deep Blue Sea,” p. 331; Telegram 4560.


Kemp, “The Nonproliferation Emperor Has No Clothes,” 50–51; Telegram 84, Paris Embassy to State Department, 7 July 1960, in NARA, RG 59, Central Decimal Files 1960–63, 862A.1901/7-760; and William A. Crawford to Mr. McSweeney, “Soviet Attitudes on ‘Nth’ Country Problem,” 11 March 1960, in NARA, RG 59, Office of Soviet Union Affairs Subject Files 1957–1963, Box 5, European Security, General.


For Kennedy and Johnson, see Francis J. Gavin, “Blasts from the Past: Proliferation Lessons from the 1960s,” International Security, Vol. 29 No. 3 (Winter 2004/2005), pp. 100–135; and Maddock, Nuclear Apartheid, chs. 6–8.


For details, see A. A. Wells to AEC, “Classification Meeting Regarding Centrifuge Technology,” 1 March 1962, MDR release by Department of Energy (DOE); and “Centrifuge Classification Meeting,” 21 March 1962, DOE MDR; Gregory O'Donnell, Draft, 9 March 1962, in NARA, RG 59, Records of Special Assistant to the Secretary of State for Atomic Weapons and Disarmament, 1948–1962 (SAE), Box 298, 12.H Peaceful Uses Subject File.9 Gas Centrifuge 1960–62.


If the British took a position in the patent discussions, it is not shown in the U.S. record.


A. A. Wells to Commission, “Proposed Four Power Meeting on Handling Centrifuge Information,” 14 January 1964, MDR release; Memorandum of Conversation, “Netherlands: Gas Centrifuge Classification,” 7 May 1963, in NARA, RG 59, Subject-Numeric Files 1963, AE.


Wells to Commission, “Proposed Four Power Meeting on Handling Centrifuge Information,” 14 January 1964; A. A. Wells to Commission, “Proposed Four Power Meeting on Handling Centrifuge Information,” 18 February 1964, DOE MDR release; and Atomic Energy Commission, “Proposed Meeting with Dutch, British, and German Representatives on Gas Centrifuge Classification,” AEC 610/44, 4 February 1964, DOE MDR release.


W. B. McCool to AEC, “Classification of Gas Centrifuge Information,” 15 March 1964, AEC 610/48, MDR release; and Thomas L. Hughes, Bureau of Intelligence and Research, to the Secretary, “Evidence of Friction in Dutch-American Relations,” 30 June 1965, in NARA, RG 59, INR/RCRS, Reports Coordination and Review Staff, Intelligence Reports 1061 and 1963–1967, Box 5, Chron/June 1966 Research Memos. For “strong” West German opposition to an agreement, see Seaborg to McGeorge Bundy, in Lyndon B. Johnson Presidential Library (LBJL), National Security Files (NSF), Charles Johnson Papers, Box 22, Nuclear—Gas Centrifuge Technology.


For “remain free,” see McCool to AEC, “Classification of Gas Centrifuge Information,” 15 March 1964.


This and the following paragraphs draw on Union Carbide Nuclear Division, “Nth Power Evaluation,” 4 March 1964, MDR release; AEC Chairman Glenn Seaborg to Robert McNamara, 17 April 1964, DOE Open-net; and Seaborg to McGeorge Bundy, 23 November 1965, enclosing summary of Nth Power Report, in LBJL, NSF, Charles Johnson Papers, Box 22, Nuclear—Gas Centrifuge Technology.


Seaborg to McNamara, 17 April 1964; McNamara to Seaborg, 23 May 1964, in NARA, Robert S. McNamara Papers, Box 120, Reading File; and William C. Foster to Seaborg, 13 May 1964, DOE MDR release. For nonproliferation policy during 1964, see Maddock, Nuclear Apartheid, pp. 237–247.


Seaborg to McNamara, 17 April 1964; and Seaborg to Bundy, 23 November 1965. For the reference to bottling up the genie, see Charles E. Johnson to “Mac” Bundy, 10 August 1964, in LBJL, NSF, Charles Johnson Papers, Box 22, Nuclear—Gas Centrifuge Technology.


Secretary of State Rusk to Glenn Seaborg, 30 June 1964, DOE MDR release; Charles W. Thomas, Memorandum to the Files, “AEC Proposal to Retain Some Collaboration with the United Kingdom on Gas Centrifuge Information until the Present Agreement Expires on July 25, 1965,” 18 August 1964, with memoranda attached, in NARA, RG 59, Subject-Numeric Files 1964–66 (SN 64–66), FT 18-2 UK-US; and Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” p. 234. For “production technology,” see Seaborg to Bundy, 26 November 1965.


Johnson to Bundy, 10 August 1964; and Spurgeon Keeny to Donald M. Horning, “Gas Centrifuge Process,” 1 December 1965, in NARA, Records of White House Office of Science and Technology, RG 359, Box 497, Nuclear Proliferation—1965; and Journal Entry, 4 May 1970, in LOC, Seaborg Papers, Box 80.


Myron B. Kratzer, Director, Division of International Affairs, to AEC, “Gas Centrifuge Developments in Germany,” 6 May 1965, MDR release; Memorandum by R. E. Kaufman, “Luncheon Meeting with Chairman Seaborg,” 11 March 1964, in NARA, RG 59, SN 64–66, ORG AEC; Herman Pollack to the Secretary, “Reply to Chairman Seaborg's Letter of May 14, 1969 re Cooperation in the Field of Uranium Enrichment,” 6 June 1969, in NARA, RG 59, SN 67–69, AE 11-1; and Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” p. 234.


Telegram 3248, U.S. Embassy Bonn to State Department, “Nuclear Energy/Gas Centrifuge Research and Development,” 27 February 1965, in NARA, RG 59, SN 64–66, AE 5 GerW; Schrafstetter and Twigge, “Spinning into Europe,” pp. 256–257; Telegram 662, U.S Embassy The Hague to State Department, “Gas Centrifuge Research,” 1 March 1965, in NARA, RG 59, SN 64–66, AE 11, GerW-Neth; Airgram ECBUS A-69, U.S. Mission to the European Communities, Brussels, to State Department, “Euratom and German Federal Government Criticized by German Deputy in European Parliament for Passivity toward Classified Gas Centrifuge Research,” 4 August 1965, in NARA, RG 59, SN 64–66, AE 11, GerW; Kratzer to AEC, “Gas Centrifuge Developments in Germany,” 6 May 1965. On the Dutch, see J. C. C. Voorhoeve, Peace, Profits, and Principles: A Study of Dutch Foreign Policy (The Hague: T. M. C. Asser Press, 1979), p. 116.


Kratzer to AEC, “Gas Centrifuge Developments in Germany,” 6 May 1965.


Telegram 3137, State Department to U.S. Embassies Bonn and The Hague, 16 April 1965, in NARA, RG 59, SN 64–66, AE 11, GerW; and Telegram 787, State Department to U.S. Embassies Bonn and The Hague, 16 April 1965, in NARA, RG 59, SN 64–66, AE 11, GerW. This is a cross-reference copy of page 1 only; the full version remains classified.


Telegram 4144, U.S. Embassy Bonn to State Department, “FRG-Netherlands Centrifuge Agreement,” 22 April 1965, in NARA, RG 59, SN 64–66, AE 5, GerW; Telegram 832, U.S. Embassy The Hague to State Department, “Gas Centrifuge Program,” 22 April 1965, in NARA, RG 59, SN 64–66, AE 11, GerW-Neth; Telegram 6812, Bonn Embassy to State Department, “Gas Centrifuges,” 7 December 1966, in NARA, RG 59, SN 64–66 FT 18-2; and Schrafstetter and Twigge, “Spinning into Europe,” 257–360.


Atomic Energy Commission, “Summary Notes of Briefing on Gas Centrifuge, Thursday, June 30, 1966,” 27 July 1966, in LOC, Seaborg Papers, Box 638, Summary Notes of Meetings June-Oct. 1966; and AEC, A Study of Gas Centrifuge as It Relates to the Proliferation of Nuclear Weapons, n.d. [circa January 1967], DOE MDR Release.


“Summary Notes of Briefing on Gas Centrifuge”; and U.S. Department of State to U.S. Embassy Bonn et al., “Gas Centrifuge Technology,” 21 March 1967, in NARA, RG 59, SN 67–69, FT 18-2.


Telegram 95676, State Department to U.S. Embassies Bonn, The Hague, and London, “Gas Centrifuges,” 5 December 1966, in NARA, RG 59, SN 64–66, FT 18-2.


Telegram 6812, 7 December 1966; and Memorandum, Abraham S. Friedman, Acting Director, Division of International Affairs, to Chairman Seaborg et al., “Gas Centrifuge Classification Meeting with U.K., Germany, and the Netherlands,” 17 February 1967, DOE MDR release.


Friedman to AEC, “Gas Centrifuge Classification Meeting,” 17 February 1967; and Telegram 105170, State Department to U.S. Embassy Tokyo, 9 December 1966, in NARA, RG 59, SN 64–66, Def 12, Chicom. On general concern about exports to China that could support the nuclear industry, see Telegram 3190, U.S. Embassy Tokyo, 28 October 1966, in NARA, RG 59, SN 64–66, DEF 12, Chicom; and Telegram 82941, State Department, 10 November 1966, in NARA, RG 59, SN 64–66, DEF 12, Chicom.


Telegram 4497, U.S. Embassy Tokyo to State Department, 20 December 1966, in NARA, RG 59, SN 64–66, DEF 12, Chicom; and Telegram 4611, U.S. Embassy Tokyo to State Department, 27 December 1966, in NARA, RG 59, SN 64–66, DEF 12, Chicom.


Morris Low, Science and the Building of a New Japan (New York: Palgrave, 2005), pp. 92–96; Hitoshi Yoshioka, “Nuclear Power Research and the Scientists’ Role,” in Shigeru Nakayama, ed., A Social History of Science and Technology in Contemporary Japan, Vol. 2, Road to Self-reliance 1952–1959 (Melbourne: Trans Pacific Press, 2001), pp. 194–224; and Airgram A-167, U.S. Embassy Tokyo, McCool, AEC, Tokyo to State Department, “Discussions of Possible Classification of Japanese Gas Centrifuge Information,” 4 August 1967, in NARA, RG 59, SN 67–69, AE 1-1, Japan-US.


Telegram 6908, U.S. Embassy Tokyo to State Department, 28 March 1967, in NARA, RG 59, SN 67–69, Def 12, Chicom; Telegram 172918, State Department to U.S. Embassy Tokyo, 11 April 1967, in NARA, RG 59, SN 67–69, Def 12, Chicom; and Airgram A-414, State Department to U.S. Embassy Tokyo, “USAEC Request for Meeting with Government of Japan,” 20 June 1967, in NARA, RG 59, SN 67–69, AE 1-1, Japan-US.


Telegram 1296, U.S. Embassy Tokyo, “Classification of Gas Centrifuge,” 29 August 1967, in NARA, RG 59, SN 67–69, DEF 12, Chicom. See also Airgram A-1670, 4 August 1967.


Telegram 31009, State Department to U.S. Embassy Tokyo, “Classification of Gas Centrifuge,” 1 September 1967, in NARA, RG 59, SN 67–69, AE 11-1, Japan-US.


Ibid.; and Airgram A-669, U.S. Embassy Tokyo to Department of State, “US-Japan Gas Centrifuge Discussions—November 6, 1967,” 22 November 1967, in NARA, RG 59, SN 67–69, AE 12 Japan-US.


Airgram A-669, 22 November 1967; and Telegram 31009, 1 September 1967.


Thomas P. Shoesmith, Deputy Chief of Mission, to William C. Sherman, 14 August 1974, in NARA, RG 59, Office of Country Director for Japan, Records Relating to Japanese Political Affairs, 1960–1975, Box 11, AE R&D Uranium Enrichment US/Japan 1974. Myron Kratzer, who had been appointed AEC representative in Japan, wrote this report. A complaint in September 1969 by the FRG government about a Mitsubishi patent filing “apparently making … some of the technology involved … available throughout the world” suggests that a proprietary secrecy policy was not applied overnight. Memorandum of Conversation, “Gas Centrifuge Process,” 3 September 1969, in NARA, RG 59, SN 67–69, INCO, 11-1, Ger W.


Hillenbrand to the Secretary, “Nuclear Gas Centrifuge System,” 20 March 1969, in NARA, RG 59, SN 67–69, AE 6.


“Dutch Announce Uranium Process,” The New York Times, 1 March 1968; “Dutch Are Still Years Away from Joining Atomic Club,” The Washington Post, 3 March 1968; Schrafstetter and Twigge, “Spinning into Europe,” pp. 255–260; Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” pp. 236–238; Telegram 982, U.S. Embassy London to State Department, “Tripartite Centrifuge Project: Report on Bonn Meeting,” 6 February 1969, in NARA, RG 84, Records of U.S. Mission to IAEA, Box 10, SCI 10, FRG/UK/Dutch Centrifuge Cooperation—1969.


Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” p. 238; and Memorandum of Conversation, “Gas Centrifuge Process for Uranium Enrichment,” 12 April 1968, in NARA, RG 59, SN 67–69, AE 11-1.


Memorandum of Conversation, “Gas Centrifuge Process for Uranium Enrichment—NPT,” with talking points attached, 16 April 1968, in NARA, RG 59, SN 67–69, AE 11-1.


Krige, “Proliferation Risks of Gas Centrifuge Technology at the Dawn of the NPT,” p. 222.


Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” p. 241.


Schrafstetter and Twigge, “Spinning into Europe,” pp. 261–264; Memorandum of Conversation, “European Collaboration on Gas Centrifuge,” 8 November 1968, in NARA, RG 59, SN 67–69, FT 18-2; Memorandum of Conversation, “European Uranium Enrichment Project,” 1 May 1968, in NARA, RG 59, SN 67–69, INCO Uranium Eur W; and Telegram 7240, U.S. Embassy The Hague to State Department, “The Dutch, URENCO, and German Plans for a Uranium Enrichment Plant,” 29 December 1978, in NARA, RG 59, Access to Archival Databases (AAD), Telegrams 1978. Apparently, some West Germans opposed the centrifuge project precisely because of the potential military applications and their doubt that cascades of centrifuges could ever work effectively. See J. Robert Schaetzel to Philip J. Farley, 30 September 1968, in NARA, RG 59, SN 67–69, AE 11-1.


AEC Secretariat AEC 610/128, “U.S. Policy Concerning Cooperation with Foreign Isotope Enrichment Activities,” 16 September 1968, DOE MDR release; and Abraham Katz through George Springsteen to Mr. Leddy, “European Nuclear Fuel Enrichment Facility—Summary and Conclusions,” 2 July 1968, in NARA, RG 59, SN 67–69, Inco-Uranium. For a policy of cooperation, see Donovan Q. Zook to Abraham Katz, “US Assistance to Foreign Isotope Enrichment Plant,” 29 August 1968, in NARA, RG 59, SN 67–69, AE 11-1.


Zook to Katz, 29 August 1968; and Memorandum of Conversation, “Classification of Gas Centrifuge Technology,” 22 October 1968, in NARA, RG 59, SN 67–69, FT 18-2.


Journal Entries, 18 July 1968 and 11 November 1968, in LOC, Seaborg Papers, Box 71; and Memorandum of Conversation, “Centrifuge Classification,” 13 November 1968, in NARA, RG 59, SN 67–69, F-T 18-2.


Roland S. Homet to Mr. Lehman, “Dissemination of US-UK Gas Centrifuge Technology,” 2 December 1968, in NARA, RG 59, SN 67–69, AE 11-1.


U.S. Atomic Energy Commission Secretariat, “Proposed U.S. Positions for December 5 and 6 Meeting with the U.K. on Classification of Gas Centrifuge,” AEC 610/140, 29 November 1968, DOE MDR release. By contrast, a British diplomat informed a U.S. embassy official that the British project was “considerably more advanced than that of the FRG or Netherlands.” See Telegram 19841, U.S. Embassy Bonn to State Department, “German-Dutch-Centrifuge Cooperation (Current Views in Germany),” 27 November 1968, in NARA, RG 59, SN 67–69, AE 11-1.


“Highlights of December 5–6 Discussions with UK on Gas Centrifuge Classification,” AEC 610/147, 16 December 1968, DOE MDR release. See also Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” p. 243.


“Highlights of December 5–6 Discussions,” 16 December 1968; and Telegram 285413, State Department to U.S. Embassy London, “Classification Gas Centrifuge Technology,” 11 December 1968, in NARA, RG 59, SN 67–69, AE 11-1. For the controversy over transfer of U.S. centrifuge technology, see Krige, “U.S. Technological Superiority and the Special Nuclear Relationship,” pp. 244–246; and Twigge, “A Baffling Experience,” pp. 151–163.


Stanley M. Cleveland to Wolfgang J. Lehman, 26 February 1969, in NARA, RG 59, SN 67–69, AE 11-1; and Abraham Katz to Mr. Hillenbrand, “UK-FRG-Dutch Gas Centrifuge Project,” 28 February 1969, in NARA, RG 59, Bureau of European Affairs, Office of OECD, European Community and Atlantic Political-Economic Affairs, Records Relating to Scientific and Technological Affairs, 1963–1974 (S&T Affairs), Box 4, NPT Safeguards Fuel Supply Centrifuge etc.


For reports on the Nixon-Wilson talks, see Katz to Hillenbrand, 28 February 1969; and Krige, “The Proliferation Risks of Gas Centrifuge Enrichment,” p. 224. For a briefing paper prepared for Nixon's talks with Wilson, see “Talking Points—Wilson,” 13 February 1969, in NARA, RG 59, Conference Files, Box 485, CF 343 Pres. Nixon's Trip to Europe 2/23–3/2/69 Briefing Memoranda Vol. 6 of 8.


Telegram 15200, U.S. Embassy London to State Department, “French Joining Centrifuge Group,” 17 December 1968, in NARA, RG 59, SN 67–69, AE 11-1; Telegram 20586, U.S. Embassy Bonn, “FRG Invitation for French to Join Centrifuge Group,” 17 December 1968, in NARA, RG 59, SN 67–69, AE 11-1; Telegram 25624, U.S. Embassy Paris to State Department, “Ultracentrifuge Project,” 20 December 1968, in NARA, RG 59, SN 67–69, AE 11-1; Telegram 900, U.S. Embassy Paris to State Department, “Gas Centrifuge Project,” 21 January 1969, in NARA, RG 59, SN 67–69, AE 11-1; and Telegram 2173, U.S. Embassy Paris to State Department, “Gas Centrifuge Project,” 13 February 1969, in NARA, RG 59, SN 67–69, AE 11-1. See also Telegram 4560.


Memorandum of Conversation, “General de Gaulle's Concern over the Centrifuge Project,” 20 March 1969, in Richard Nixon Presidential Library (RNPL), National Security Files (NSF), Box 674, France Vol. 1 (20 Jan–11 April 1969) [2 of 2]. For French efforts to undermine the project, see Schrafstetter and Twigge, “Spinning into Europe,” pp. 268–269; and Telegram 981, 13 March 1969. On de Gaulle's containment policy toward the FRG in the 1960s and his concerns about West German nuclear potential, see Garrett Joseph Martin, General de Gaulle's Cold War: Challenging American Hegemony, 1963–1968 (New York: Berghahn, 2014), pp. 63, 67, 107; and Jacques E.C. Hymans, The Psychology of Nuclear Proliferation: Identity, Emotions, and Foreign Policy (Cambridge, UK: Cambridge University Press, 2006). p. 113.


Memorandum of Conversation, “General de Gaulle's Concern over the Centrifuge Project,” 20 March 1969; and Kissinger to the President, “De Gaulle's Message to You Complaining of UK-German-Dutch Gas Centrifuge Project,” 21 March 1969, in NSF, Box 674, France Vol. 1 (20 Jan–11 April 1969) [2 of 2]. For “benevolent,” see Hillenbrand to the Secretary, 20 March 1969.


Kissinger to Secretary of State, 29 March 1969, in NARA, RG 59, SN 67–69, AE 6; Memorandum of Conversation, 31 March 1969, in U.S. Department of State, Foreign Relations of the United States, 1969–1972, Vol. XLI, pp. 456, 459–460. In response to a “lower-level French inquiry,” the State Department sent a parallel message to the French Foreign Ministry after receiving White House approval. See Telegram 56541, State Department to U.S. Embassy Paris et al., “European Gas Centrifuge Cooperation: GOF Request for U.S. Views,” 12 April 1969, in NARA, RG 59, SN 67–69, AE 11-1.


W. J. Lehman to Mr. Getz, 2 May 1969, in NARA, RG 59, SN 67–69, AE 11-1.


Journal Entries, 13 February, and 10, 17, and 20 March 1969, in LOC, Seaborg Papers, Box 72.


On decision-making at the AEC, see Michael J. Brenner, Nuclear Power and Non-proliferation: The Remaking of U.S. Policy (London: Cambridge University Press, 1981), pp. 41–43.


Journal Entry, 20 March 1969, in LOC, Seaborg Papers, Box 72; Katz to Hillenbrand, 28 February 1969; and Schrafstetter and Twigge, “Spinning into Europe,” pp. 266–268.


David F. Biltchik to Mr. Katz, “UK-FRG-Dutch Gas Centrifuge Project: US-UK Consultations,” 8 March 1969, in NARA, RG 59, SN 67–69, AE 11-1.


Memorandum of Conversation, “UK/Netherlands/FRG Collaboration on Gas Centrifuge,” 4 June 1969, with “Speaking Notes Centrifuge” attached, in NARA, RG 59, SN 67–69, AE 11-1; and Krige, “U.S. Technological Superiority and the Special Nuclear Relationship.” The British also acknowledged that the “Gas-Baffles” (which drove the flow of uranium gases) of their production model were influenced by U.S. restricted data.


“Telcons 6 June 1969, Under Secy Johnson,” in NARA, RG 59, Records of U.A. Johnson, Box 74, Telcons Personal Amb U.A. Johnson June 1969; Journal Entry, 3 May 1969, in LOC, Seaborg Papers, Box 73, Journals 30 April–4 May 1969; Journal Entry, 6 June 1969, in LOC, Seaborg Papers, Box 74, Journals 1 June 1969–9 June 1969; and Telegram 93701, State Department to U.S. Embassy London, “Tripartite Gas Centrifuge Project,” 10 June 1969, AE 11-1.


Nelson Sievering to Commissioner Theos Thompson, “Reflections on the Gas Centrifuge Meetings with the UK,” 31 July 1969, in NARA, RG 59, S&T Affairs, Box 2, S.23 Gas Centrifuge Technology 1969; and AEC 610/184, “Letter to Chairman, JCAE on UK Gas Centrifuge,” 14 August 1969, DOE MDR release.


Journal Entry, 8 September 1969, in LOC, Seaborg Papers, Box 75; Nelson F. Sievering to Mr. Katz and Mr. Lehman, “Gas Centrifuge—AEC Draft Aide Memoire for UK,” n.d. [ca. 9 September]; Abraham Katz to Mr. Hillenbrand, “Tripartite Centrifuge Project—Article IX (C) Issue,” 30 September 1969, in NARA, RG 59, S&T Affairs, Box 2, S.23 Gas Centrifuge Technology 1969; and Twigge, “A Baffling Experience,” p. 159.


James Phillips to Mr. Katz, “Tripartite Centrifuge Project,” 12 June 1969; Memorandum of Conversation, “Tripartite Gas Centrifuge,” 31 July 1969; Telegram 2054, U.S. Embassy The Hague, “Gas Centrifuge Developments,” 27 June 1969, all in NARA, RG 84, Mission Records, Box 10, SCI 10 FRG/UK/Dutch Centrifuge Cooperation—1969; and Twigge and Schrafstetter, “Spinning into Europe,” pp. 269–270.


Telegram 1988, U.S. Embassy London to State Department, “Tripartite Centrifuge Cooperation: March 11 Ministerial Meeting,” 14 March 1969, in NARA, RG 59, SN 67–69, AE 11-1; J. D. Phillips to the File, “Tripartite Project,” 10 July 1969, in NARA, RG 59, Bureau of European Affairs, Office of OECD, European Community and Atlantic Political-Economic Affairs, Records Relating to Scientific and Technological Affairs, 1963–1974, Box 2, S.23 Gas Centrifuge Technology 1969; and Nelson Sievering to Mr. Katz, “Tripartite Centrifuge Arrangement,” 23 July 1969, in NARA, RG 59, SN 67–69, AE 11-1.


Memorandum of Conversation, “The Tripartite Gas Centrifuge Project,” 24 October 1969, in NARA, RG 59, SN 67–69, AE 11-1; and Netherlands Embassy confidential note, 18 December 1969, in NARA, RG 59, S&T Affairs, Box 2, S.23 Gas Centrifuge Technology 1969. For details on NATO nuclear information security procedures, see Dean Rusk to President Johnson, 22 June 1964, enclosing “Agreement Between the Parties to the North Atlantic Treaty for Co-operation Regarding Atomic Information,” in NARA, RG 59, SN 64–66, DEF 10–1, NATO. For the ATOMAL system, see Allied Command Europe, ATOMAL Classification Handbook, n.d., in NARA, CIA Research Tool.


U.S. Embassy Bonn A-773 to State Department, “NUCLEAR ENERGY—‘CENTEC’ AND ‘URENCO,’ International Companies formed under Tripartite Agreement on Gas Centrifuge Development for Uranium Isotope Separation,” 3 September 1971, in NARA, RG 59, Subject-Numeric Files 1970–73, AE 11-1; C. L. Marshall to Chairman Schlesinger et al., “Quadripartite Classification Policy for Gas Centrifuge Information,” 21 January 1971, with attachment, DOE MDR release; and C. H. van Vierasen, Embassy of Netherlands, to Donovan Q. Zook, 9 December 1971, enclosing “Tripartite statement on Classification Policy for the Gas Centrifuge Projects,” DOE MDR release.


Delmar L. Crowson to Chairman Schlesinger et al., “IAEA Safeguards for Enrichment Plants,” 12 May 1972, enclosing “Talking Points for Use with Ambassador Glennan and ACDA,” DOE MDR release; and Marshall to Schlesinger et al., “Quadripartite Classification Policy for Gas Centrifuge Information.”


SECY-2486, “Consent Calendar Item: Draft Quadripartite Classification Guide for Gas Centrifuge Information,” 15 May 1973, DOE MDR release; Draft, “Quadripartite Gas Centrifuge Classification Conference,” 5 June 1972, DOE MDR release; and A. S. Friedman to Klaus Gottstein, German Embassy, 7 August 1973, DOE MDR release. The draft guide remains entirely classified.


For early accounts, see Edward F. Wonder, Nuclear Fuel and American Foreign Policy: Multilateralization for Uranium Enrichment (Boulder, CO: Westview Press, 1977), pp. 11–25; and Brenner, Nuclear Power and Non-proliferation, pp. 23–28.


Talking points, “A Proposal for Foreign Cooperation in the Field of Gaseous Diffusion,” n.d. [May 1969], in LOC, Seaborg Papers, Box 73, Journals 14 May–18 May 1969.


Herman Pollack to the Secretary, “Reply to Chairman Seaborg's Letter of May 14, 1969 re Cooperation in the Field of Uranium Enrichment,” 6 June 1969, with attached letter from Seaborg to Secretary of State, 14 May 1969, in NARA, RG 59, SN 67–69, AE 11-1.


Charles Van Doren to the Director [of ACDA], “Report on Meeting to Discuss Cooperation with Selected Countries in Gaseous Diffusion,” 4 June 1969, in NARA, RG 383, Arms Control and Disarmament Agency, Subject Files (NND 72866), Box 1, Cooperation with Selected Countries in Uranium Enrichment by Gaseous Diffusion, January–June 1969.


J. Robert Schaetzel to Kenneth Rush, 19 February 1970, enclosing letter to Glenn Seaborg, same date, in NARA, RG 59, Records of Ambassador Kenneth Rush, Box 16, Personal Correspondence-Classified.


Journal Entry, 19 February 1970, in LOC, Seaborg Papers, Box 82, Journals 17 February–21 February 1970. For the Under Secretaries Committee report to the White House, see Robert M. Behr to Dr. Kissinger, “U.S. Cooperation in the Uranium Enrichment Field,” 18 February 1970, in RNPL, National Security Council Institutional Files (NSCIF), Box H–271, U/M 56–59.


SCI-Herman Pollack to the Secretary et al., “Weekly Activities Report,” 24 April 1970, in NARA, RG 59, Executive Secretary Weekly Focus Reports, Box 11; SCI-Herman Pollack to the Secretary et al., “Weekly Activities Report,” 15 May 1970, in NARA, RG 59, Executive Secretary Weekly Focus Reports, Box 11; and NSC Under Secretaries Committee, Memorandum to the President, “A Program of International Cooperation in the Uranium Enrichment Field,” 29 June 1970, in NARA, RG 59, General Files on NSC Matters, Box 11, unlabeled file.


Herman Pollack to the Secretary, “International Cooperation in Uranium Enrichment,” 11 August 1971, with Kissinger memorandum attached, in NARA, RG 59, SN 70–73, AE 11-1; Kissinger to the President, “Proposed Program for Cooperation with Allies in the Uranium Enrichment Field,” 8 September 1970, in RNPL, NSCIF, Box H–271, Box H-271, U/M 56–59; and Statement by U. A. Johnson, 12 July 1971, enclosed with U.S. Department of State Instructions CA-3326 to U.S. Mission IAEA, “Possible Utilization of U.S. Classified Gaseous Diffusion Technology for Multinational Uranium Enrichment Plants in Other Countries,” 14 July 1971, in NARA, RG 59, SN 70–73, INCO URANIUM.


Robert Behr, “Reply to Under Secretary Johnson's Letter on Uranium Enrichment, 17 September 1970, and Robert Behr and Helmut Sonnenfeldt to Kissinger, “Breaking the Log Jam re Cooperation with Allies in the Uranium Enrichment Field,” 12 April 1971, both in NSCIF, Box H-271, U/M 56–59.


Kissinger to Schultz, “Uranium Enrichment,” 20 April 1971, in RNPL, NSCIF, Box H-271, U/M 56–59; SCI-Donovan Q. Zook to the Secretary, “Weekly Focus Report—December 19–29, 1970,” 29 December 1970, in NARA, RG 59, Executive Secretary Weekly Focus Reports, Box 13; SCI-Herman Pollack to the Under Secretary, “U.S. Uranium Enrichment Capacity,” 6 November 1970, in NARA, RG 59, Executive Secretary, Summaries of the Under Secretary's Meetings with the National Security Adviser, Box 1, Irwin/Kissinger Lunches 1970–1971; and Brenner, Nuclear Power and Non-Proliferation, pp. 18, 30–31.


“Special Message to the Congress on Energy Resources,” 4 June 1971, Public Papers of the President of the United States: Richard Nixon, Containing the Public Messages, Speeches, and Statements of the President 1971 (Washington, DC: Government Printing Office, 1972), p. 711; and Telegram 1846, U.S. Embassy Ottawa to State Department, “Uranium Enrichment Cooperation: Washington Talks,” 11 November 1971, in NARA, RG 59, SN 70–73, Inco-Uranium. For views within the AEC and details on the proposal, see Wonder, Nuclear Fuel and American Foreign Policy, pp. 16–22.


U.S. Department of State, Bureau of International Scientific and Technological Affairs, “International Aspects of the U.S. Uranium Enrichment Program,” 24 September 1973, in NARA, RG 59, SN 70–73, Inco-Uranium; Wonder, Nuclear Fuel and American Foreign Policy, pp. 23–25; Brenner, Nuclear Power and Non-Proliferation, pp. 14–15; “France to Produce Enriched Uranium in $1.5 Billion Plant,” The Washington Post, 25 November 1973; and Thomas O'Toole, “U.S. Loses Dominance in Uranium,” The Washington Post, 16 November 1975. For the last gasp of enrichment technology sharing, the Uranium Enrichment Associates proposal, see Shinsuke Tomotsugu, “After the Hegemony of the ‘Atoms for Peace’ Program: Multilateral Nonproliferation Policy under the Nixon and Ford Administrations,” Japanese Journal of American Studies, No. 27 (2016), pp. 167–188.


Atomic Energy Commission Policy Session Item, “IAEA Safeguards in Isotope Separation Facilities,” SECY 2247, 20 April 1972, DOE MDR release; W. B. McCool to D. L. Crowson, Nuclear Materials Security, “IAEA Safeguards in Isotope Separation Facilities,” 9 May 1972, DOE MDR release; and General Manager to Chairman Schlesinger et al., “IAEA Safeguards for Enrichment Plants,” 12 May 1972, DOE MDR release.


C. H. Van Vieresen to Donovan Q. Zook, 17 May 1972, in NARA, RG 59, SN 70–73, AE 11-1.


Telegram 4835, U.S. Mission to European Community to State Department, “IAEA/EURATOM Safeguards Agreement,” 8 December 1972, Telegram 17234, U.S. Embassy Bonn to State Department, “IAEA/EURATOM Safeguards,” 19 December 1972, both in NARA, RG 84, Records of U.S. Mission to IAEA, Box 20, AE 13 EURATOM/IAEA Safeguards Negotiations; Telegram 7658, U.S. Mission to IAEA to State Department, “IAEA Safeguards on Enrichment Plants,” 8 September 1975, in NARA, RG 59, AAD Telegrams 1975; Telegram 9627, U.S. Mission to IAEA to State Department, “IAEA Safeguards at Centrifuge Isotope Enrichment Plants,” 24 October 1978, in NARA, RG 59, AAD Telegrams 1978; and B. G. Dekker and E. F. M. Steinbach, “The Development and Experience of Safeguards at the Dutch and German Enrichment Plants (URENCO),” The Transactions of the American Nuclear Society, Vol. 55 (1987), p. 12.


Adrian Levy and Catherine Scott-Clark, Deception: Pakistan, the United States, and the Secret Trade in Nuclear Weapons (New York: Routledge, 2007), pp. 26–33; and Joop Boer et al., A. Q. Khan, URENCO, and the Proliferation of Nuclear Weapons Technology: The Symbiotic Relationship between Nuclear Energy and Nuclear Weapons (London: Greenpeace International, 2004), p. 9. For Khan and the Pakistani nuclear program, see Feroz Hassan Khan, Eating Grass: The Making of the Pakistani Bomb (Stanford CA: Stanford University Press, 2012), esp. pp. 139–147; and Kemp, “The Nonproliferation Emperor Has No Clothes,” pp. 64–65.


Telegram 114853, State Department to U.S. Embassy in London et al., “Proposed Quadripartite Enrichment Classification Meeting,” 5 May 1978, and follow-up telegrams, in NARA, RG 59, AAD Telegrams 1978.


Kemp, “The Nonproliferation Emperor Has No Clothes,” p. 77.