This article reviews several recent books on the Islamic State in order to understand its goals, motivations, strategy, and vulnerabilities. It argues that the Islamic State's ideology is powerful but also highly instrumental, offering the group legitimacy and recruiting appeal. Raison d'etat often dominates its decisionmaking. The Islamic State's strength is largely a consequence of the policies and weaknesses of its state adversaries. In addition, the group has many weaknesses of its own, notably its brutality, reliance on foreign fighters, and investment in a state as well as its tendency to seek out new enemies. The threat the Islamic State poses is most severe at the local and regional levels. The danger of terrorism to the West is real but mitigated by the Islamic State's continued prioritization of the Muslim world and the heightened focus of Western security forces on the terrorist threat. A high-quality military force could easily defeat Islamic State fighters, but there is no desire to deploy large numbers of Western ground troops, and local forces have repeatedly shown many weaknesses. In the end, containing the Islamic State and making modest rollback efforts may be the best local outcomes.


Patrick Cockburn: The Rise of the Islamic State: ISIS and the New Sunni Revolution (London: Verso, 2015)

William McCants, The ISIS Apocalypse: The History, Strategy, and Doomsday Vision of the Islamic State (New York: St. Martin's, 2015)

Jessica Stern and J.M. Berger, ISIS: The State of Terror (New York: Ecco, 2015)

Joby Warrick, Black Flags: The Rise of ISIS (New York: Doubleday, 2015)

Michael Weiss and Hassan Hassan, ISIS: Inside the Army of Terror (New York: Regan Arts, 2015)

Politicians and pundits alike appeared shocked when the Islamic State conquered vast swathes of Iraq in 2014, punctuating its prowess with highly publicized beheadings, systematized sexual slavery, mass killings of religious minorities, and other atrocities. Although the Islamic State changes its name regularly, the group is by no means new: its predecessor organization emerged after the 2003 U.S. invasion of Iraq and quickly assumed an important role in the overall insurgency. The apparent U.S.-led success in beating it back by the end of the decade, however, led U.S. leaders to assume that the group was moribund, and it ceased to be a priority.1 This neglect continued even after the civil war in Syria heated up and the group reestablished itself there, while becoming more active in Iraq.2

The Islamic State has evolved from its origins in Iraq after the U.S. invasion into a transnational movement with a base in Iraq and Syria, and so-called provinces—groups claiming control over territory in other parts of the Muslim world that have sworn loyalty to the Islamic State and are recognized in turn—in almost a dozen countries. It also claims thousands of supporters in the West. It has achieved more than al-Qaida ever has, and it has many more recruits and far more support among Muslims as well. In 2014, when the group's battlefield advances and atrocities grabbed world attention, the United States again made the Islamic State a priority. Since then the Barack Obama administration, reluctant to engage in wars in the Middle East, has sent ground troops to Iraq and Syria to help train allies to fight the Islamic State, while using air power to strike it directly. When announcing the intervention, President Obama cautioned: “I've been careful to resist calls to turn time and time again to our military.” He concluded, however, that “we will take action” when the lives of Americans and innocent civilians are at risk.3 This concern is shared—indeed magnified—across the aisle, with many Republicans calling for more aggressive air strikes, among other steps.4 The November 2015 Paris attacks, in which Islamic State operatives killed 130 people, and the home-grown strike in San Bernadino, California, in December 2015 that killed 14, further elevated concern about the reach of the Islamic State. A post-Paris poll found that almost two-thirds of Americans believed that a Paris-style attack could happen near them; another poll found that fear of terrorism is at its highest level since the terrorist attacks of September 11, 2001.5

Yet confusion persists. Politicians and pundits alike often describe the Islamic State as a new organization. More important, its basic nature is misunderstood, with the label “terrorist” still being the most common descriptor, even though that term misleads more than it illuminates.6 The Islamic State is also often paired with al-Qaida, despite their mutual enmity and different organizational and strategic approaches. Finally, the group is wrongly portrayed as fanatical, despite its many pragmatic decisions and strategies. Given this confusion, it is no surprise that policymakers and pundits do not understand the Islamic State's true strengths and weaknesses. This lack of understanding has resulted in poor assessments about the threat the group poses, both to the region and to the United States, and how best to fight it.

Fortunately, the Islamic State has begun to receive more serious attention from, among others, journalists and think tank experts. Recently published books illuminate many neglected aspects of the organization and move beyond the caricature in the public debate.7 This essay draws on these works, as well as on serious journalistic accounts and follow-on pieces written by the same scholars and others, to paint a portrait of the Islamic State and answer the following questions: What are the origins of the Islamic State? What does it want, and how does its ideology interact with its overall strategy? What are the group's strengths and weaknesses? How does the Islamic State differ from al-Qaida? What threat does it pose to the region and to the United States? And, finally, how might it best be countered?

This essay argues that the ideology of the Islamic State shapes whom the group sees as an adversary; the group's mode of governance; and, more rarely, its military operations. Yet its ideology is also highly instrumental, giving the group legitimacy and recruiting appeal, as well as a path toward creating a state. Indeed, at the core of the Islamic State's ideology and strategy is an effort to consolidate its existing state through the monopolization of violence, brutality, service provision, and proselytization, and then expanding it (usually opportunistically, through conventional and guerrilla warfare). Its foreign policy is that of a revolutionary state, aggressive and inciting alarm among neighbors. Its use of terrorism, therefore, should be considered within this context: most, but not all, of what the Islamic State does with regard to terrorism is an adjunct to its effort to advance its state power by fomenting sectarian conflict and intimidating rivals. Foreign fighters play an important—and unusual—role in this endeavor, offering the group large numbers of dedicated fighters, with many assuming leading roles. The Islamic State's strength, however, is largely a consequence of the policies and weaknesses of its state adversaries. In addition, the group itself has many weaknesses. Notably, its numerous acts of brutality, reliance on foreign fighters, and investment in the building of a state are potential long-term vulnerabilities, as is its tendency to seek out new enemies.

The threat the Islamic State poses is real, yet it can easily be exaggerated. The threat is most severe at the local and regional levels. If the Islamic State is not contained, it could conquer more territory. Additionally, its use of terrorism and efforts to foment strife could destabilize Iraq's and Syria's neighbors, and some of its provinces pose a threat to the stability of regimes in the Middle East and North Africa such as Libya. The danger of terrorism to the West is real, as the 2015 Paris and San Bernadino attacks illustrate. There are important factors, however, that can mitigate the threat, ranging from the Islamic State's continued prioritization of the region to the heightened focus of Western security forces on the terrorist threat.

The task of fighting the Islamic State is both straightforward and fiendishly difficult. Given the frequent political limits or strategic priorities of the group's many foes, not all of its strengths can be countered or weaknesses exploited. On the one hand, rolling back its forces from the territory it holds in Iraq and Syria would be relatively easy for a large, NATO-quality military force; unlike al-Qaida, the Islamic State has a more traditional center of gravity. On the other hand, there is no U.S. or European desire to deploy large numbers of ground troops, and local forces have repeatedly shown many weaknesses. Air power can help hold the line, but without a substantial ground presence it will be hard drive the Islamic State from much of the territory it controls or to consolidate any gains. In addition, the Islamic State has demonstrated skill in the past at using terrorism and guerrilla war to harass occupying forces. Any outside military presence would require years to bolster a sound local government that could impose order and provide services—a combination that for now appears unlikely. In the near term, containing the Islamic State and making modest rollback efforts may be the best possible local outcomes. Internationally, however, the United States can use measures similar to those it employed against al-Qaida affiliates and networks in the West to disrupt potential terrorist plots.

The first section of this essay offers a brief history of the Islamic State from its origins in Iraq to the present day. In the second section, the Islamic State's ideology and strategies are examined to understand how they intersect. In the third section, the group's state-building effort is assessed. Its strengths and weaknesses are discussed in the fourth section, and the fifth section examines the current level of threat the group poses. The conclusion explores the implications of this analysis for U.S. and allied counterterrorism.

Origins of the Islamic State

Although the Islamic State burst onto the international scene in 2014, when it surged across Iraq while engaging in spectacular brutality, the group by then had been in existence for a decade or more. If the story of al-Qaida is that of the Arab Afghans and their legacy, the story of the Islamic State begins with the 2003 Iraq War.8

The books reviewed in this essay trace the roots of the group to the founder of al-Qaida in Iraq (AQI), Abu Musab al-Zarqawi, whose brutality earned him the sobriquet “the sheikh of the slaughterers.”9 Indeed, even though Zarqawi was killed in 2006, his words, philosophy, and deeds are clearly present in the Islamic State today.

Although Zarqawi left his native Jordan to fight in Afghanistan, he did not battle Soviet forces directly; instead he fought against the Soviet-backed regime that remained in place for several years after the 1989 Soviet withdrawal. Upon returning to Jordan, he was arrested. In prison, he forged a close connection to Abu Muhammad al-Maqdisi, a Salafi preacher who has emerged as one of the most important jihadist thinkers of the current age.10

After his release from prison in 1999, Zarqawi returned to Afghanistan, where he began his relationship with al-Qaida. Osama bin Laden, however, disliked Zarqawi's emphasis on fighting the Shiites, whom the Jordanian jihadist called “a sect of treachery and betrayal” (Warrick, p. 127). Nevertheless, in 2000 bin Laden gave Zarqawi seed money to organize and train a group of fighters from the Levant area, where al-Qaida was organizationally weak. After the U.S. defeat of the Taliban in 2001, Zarqawi fled to Iran. Following a brief stay, he traveled to Iraq in advance of the 2003 U.S. invasion. There, he prepared networks to fight the Americans (Warrick, pp. 66–70). His organizations took on many names, starting with Tawhid wal Jihad. In 2004 Zarqawi pledged loyalty to bin Laden, and his group assumed the name al-Qaida in Iraq.

After the 2003 invasion, the United States failed to secure Iraq and impose order. Extensive de-Baathification and the disbanding of the military alienated Iraq's Sunni Muslim community and put tens of thousands of young men with military experience on the streets.11 As Joby Warrick acidly writes, “If Abu Musab al-Zarqawi could have dictated a U.S. strategy for Iraq that suited his own designs for building a terrorist network, he could hardly have come up with one that surpassed what the Americans themselves put in place over the spring and summer of 2003” (Warrick, p. 117).

Yet Zarqawi's own role in fomenting the chaos was considerable. His first three targets—the United Nations headquarters in Baghdad, the Jordanian embassy there, and a leading moderate Shiite cleric—revealed his many enemies: the international community, Arab regimes, and the Shiites. Strategically, the attacks scared off foreign aid workers, helped isolate Iraq in the Arab world, and encouraged a sectarian war (Warrick, p. 113). Zarqawi later achieved even greater fame by personally beheading American contractor Nicholas Berg in 2004. Most Muslims condemned this act of brutality, though a small but hardcore group of supporters embraced it. By disseminating videos of his group's and his own bloody deeds, Zarqawi proved skilled in using terrorism to market his group and instill fear.

After Zarqawi's death in 2006, his group would take on other names, notably in that same year declaring itself the Islamic State of Iraq—its first attempt to proclaim a state. Although the group would change its name regularly, brutality remained a constant; attacks on civilians including children in “playgrounds and schoolyards,” prisoners, and kidnapping victims occurred on a daily basis (Weiss and Hassan, p. 34, quotation on p. 42). In response, Shiite groups formed their own militias, complete with power drills and electrical cords, while the Tigris swelled with bodies.12 At that time, the Islamic State seemed to be succeeding brilliantly: Iraq was consumed by a massive civil war, with civilians dying at a rate of more than fifty a day (Stern and Berger, p. 27), and the government was on the verge of collapse.

Despite having succeeded in fomenting the sectarian civil war it so desired, al-Qaida in Iraq overreached and almost destroyed itself. The organization sought to impose its will in areas it controlled, using its declaration of a state to demand fealty and intimidate Sunnis who cooperated with the government, brutally killing them and their families if they did not comply (Warrick, p. 176). This behavior alienated local Sunni tribes, which worked with the United States against AQI. The combination of Special Operations raids, U.S. military support for local tribes, Sunni militias, and AQI missteps proved devastating, and the organization lost the vast majority of its top leadership.13 AQI's brutality had also led to a revolt within the jihadist movement, with theologians and leaders of a range of jihadist groups (including important ones in Libya and Egypt) criticizing the al-Qaida core for the killing of so many Muslims by its supposedly loyal proxy.14

The demise of AQI seemed nigh at the end of the last decade, when the United States killed the organization's heads, Abu Ayyub al-Masri and Abu Omar al-Baghdadi, in 2010 and devastated much of AQI's senior ranks. Yet, a new leader emerged—Abu Bakr al-Baghdadi—who seemed at first only to preside over the ruins of the group. As Warrick observes, “It had become irrelevant” (Warrick, p. 246). Subsequent policies by the Iraqi and Syrian regimes, however gave the failing group new life. Indeed, the fate of what would become one of the world's most powerful nonstate actors depended on the actions of its state enemies.

The story of the recovery of AQI begins in Iraq. After the U.S. withdrawal in 2011, zero-sum thinking returned to Iraqi politics, with Prime Minister Nouri al-Maliki playing “a central role in pushing the Sunni community into the arms of ISIS.”15 In the 2014 parliamentary elections, Maliki ran as the would-be champion of the Shiites who would crush a Sunni counterrevolution—an electoral ploy that became a reality (Cockburn, pp. 47–48). His government turned on Sunnis who had worked with the United States: “It didn't give them rights, it didn't pay their salaries, and it put a lot of them in jail,” as one Sunni leader put it (quoted in Weiss and Hassan, p. 81). For a community still recovering from a brutal civil war, the threat seemed existential. Many Sunnis who had fought al-Qaida in Iraq came to favor its successors over the Iraqi government; and when the Islamic State returned to Iraq in 2014, more than eighty Sunni tribes would fight with it (Stern and Berger, p. 44).

The Islamic State played no role in the post-2011 collapse of Syria into strife, but it quickly exploited it. Syria had long been a logistics hub for the Iraqi jihad—Bashar al-Assad's regime had tolerated recruitment and transit as a way of increasing the cost of the U.S. intervention in Iraq (Weiss and Hassan, pp. 103–105)—and now the jihadists used these facilitation networks to bring fighters back into Syria. Despite the apparent threat, the Syrian regime proved to be the jihadists' great friend. The Assad regime imprisoned tens of thousands of peaceful protesters but released jihadists from jail. Syrian intelligence officers reasoned, cynically but correctly, that “they will do a good job for us … we will convince the world that we are facing Islamic terrorism” (quoted in Weiss and Hassan, p. 147; see also Warrick, p. 243). Eventually, they hoped that the West would value Assad as a partner against Islamic extremism. The regime also used popular Alawi militias to commit atrocities against Sunni civilians, inviting a brutal backlash against the regime's Alawi core and other minorities that rallied regime supporters. As Shiraz Maher, an expert on radicalization, noted: “The sectarianism was carefully manufactured by Assad”; and in doing so, the Syrian dictator “set the Sunni Muslim world on fire” (quoted in Weiss and Hassan, pp. 136 and 135, respectively).

Militarily, the Syrian government targeted moderate Islamist opposition forces, letting the regime contend that the choice was between Assad and the terrorists, while allowing jihadists a relative respite to build their state. A 2014 study found that the regime focused only 6 percent of its strikes that year against the Islamic State.16 Both the Assad regime and the Islamic State concentrated on what they considered the more dangerous enemy—the moderate nationalist opposition—rather than each other (Weiss and Hassan, p. 199). Indeed, the Islamic State arose in areas where the government had already surrendered territory to the rebels and in areas far from the front lines that were no longer contested.17

For the Islamic State—and for many Iraqis, Syrians, and Muslim supporters worldwide—the Iraq and Syria conflicts fit into one narrative: that Iran and the Shiites, with U.S. support, are generally on the offensive against Sunni Muslims. Religiously, the Alawis can be seen as an offshoot of Shiism, and both the Shiite regime in Baghdad and the Alawi regime in Damascus receive Tehran's backing.18 Although U.S. leaders condemn Assad in their speeches, many Sunni Muslims see Washington's reluctance to intervene militarily as a deliberate plot to let Assad slaughter Sunnis with impunity.

At first, the Islamic State of Iraq put a Syrian face on its presence in Syria, using the organizational name Jabhat al-Nusra (JN), which declared itself on January 24, 2012. JN, however, quickly expanded and carefully followed the al-Qaida core's many lessons of winning over the people, by not imposing Islamic law, by cooperating with other groups, and by avoiding extreme brutality.19 Zawahiri had warned his fighters to exercise restraint and not to harm civilians, including those from “deviant sects,”20 and JN would even protect churches to demonstrate goodwill toward Christians (Weiss and Hassan, p. 150). JN also believed that it could win because the United States was not backing the Assad regime.

JN became so successful and so distinct in its approach from its Iraqi parent organization that the Islamic State of Iraq sought to reassert its control by declaring sovereignty over the group in April 2013. JN went over Baghdadi's head to al-Qaida's leader, Ayman al-Zawahiri, who two months later ruled that JN would engage in operations in Syria while the Islamic State of Iraq would concentrate on Iraq. Baghdadi rejected this ruling and loyalty to al-Qaida itself, leading to a schism in which hundreds died in subsequent fighting.21

The Islamic State of Iraq emerged triumphant from this internecine conflict in Syria, and its forces swept back into Iraq, seizing Mosul (the country's second-largest city) and many Sunni-populated parts of Iraq. Then, on July 4, 2014, after achieving control over large parts of Syria and Iraq, equal to an area larger than Great Britain, with more than 6 million inhabitants—an area far greater in size than the Islamic State of Iraq or al-Qaida ever held in the past—Baghdadi declared a new caliphate, with himself as caliph, and proclaimed his group's new name: the Islamic State. His forces threatened Iraq's Yazidi minority, whom they say are devil worshippers, with genocide, and the Islamic State's seemingly unstoppable advances led the Obama administration to intervene with air strikes, which began on August 8, 2014.22

The Interplay of Ideology and Strategy

Like most terrorist groups, the Islamic State is highly ideological.23 Like those of most successful groups, its ideology is often used pragmatically or subordinated to strategic goals, making it difficult to determine when its ideas truly matter and when they are meant to hide deeper goals. Ideology matters, and its influence can be seen in the Islamic State's military operations and in its list of enemies. The group's ideology, however, is instrumentalized, twisted, and subordinated to other goals, enough that it is difficult to use ideology to predict the Islamic State's actions. In addition, the group's emphasis on pragmatism often makes its ideology seem incoherent and contradictory.

Islamic State leaders and followers embrace a range of ideas that are rooted in Wahhabi teachings that reject innovation in religion, warn that outside cultural influences are dangerous, and claim that only a small number of declared Muslims are true believers (McCants, p. 151). In its propaganda, the group stresses the importance of tawhid (monotheism, but connoting hostility toward mysticism, saint worship, or anything that might involve intermediaries to God). Jihad (which the Islamic State considers to mean holy war rather than the more peaceful interpretation of jihad as an internal struggle for righteousness) is portrayed as a heroic value.24 In areas where the Islamist State rules, it claims to be implementing true Islamic law.

The Islamic State proposes an alternative nationalism, one stressing unity among the Muslim community under its leadership. It is common for terrorist groups to push a new identity, calling for workers or other potential aties to champion a political identity, though often few heed the call. As such, the Islamic State rejects traditional nation-state identities and proposes instead an absolutist Islamist one. “Syria is not for the Syrians, and Iraq is not for the Iraqis,” Baghdadi thundered when he announced the formation of the caliphate in June 2014.25 As part of this identity, the Islamic State stresses not only a sectarian danger but also the threat of foreign governments and insufficiently observant Sunnis. The Islamic State's sectarian ideology gives the group a natural constituency of Sunni Muslims from which to recruit and who are more likely to support the organization when sectarian tension is high.26

The Islamic State has a strong apocalyptic strand. McCants, whose book delves deeply into this issue, describes an organization whose rank-and-file and some of its leaders are enamored of the idea of the Mahdi, a prophetic figure who will lead true Muslims in the battle against the infidels (McCants, p. 22). As such, some Islamic State fighters believe they are living in the end of times, fighting for the forces of God against the unbelievers. Al-Qaida, in contrast, has always viewed apocalypticism with disdain, “a foolish pastime of the masses” (McCants, p. 28).

Appeals to sectarianism and apocalypticism are popular recruitment tools: by joining the Islamic State, members are defending the faithful and becoming actors in God's design for the end of times. The chaos in the Middle East, especially in Syria, which for historic reasons features prominently in the sayings of the prophet, makes many apocalyptic sayings seem relevant to today's world. In one 2012 poll, half of the Muslims surveyed believed that the Mahdi would appear any day. The Islamic State regularly makes apocalyptic references in its propaganda. Sectarianism also plays well. In one 2015 survey, at least 40 percent of Sunnis polled did not consider a Shiite to be a legitimate Muslim.27

Sectarianism is also at the core of the Islamic State's strategic doctrine. From the start, Zarqawi believed that striking the Shiites in Iraq would undermine the Iraqi government and local support for the United States. In essence, this was a provocation strategy that would “show the Sunnis their [the Shiites'] rabies and bare the teeth of the hidden rancor in their breasts” (quoted in Weiss and Hassan, p. 29).28 Furthermore, the strategy is designed to convince the undecided to join the Islamic State community: “and, whether they like it or not, many Sunni areas will stand with the mujahedin” (McCants, p. 11). The Islamic State has encouraged anti-Shiite violence in Saudi Arabia, Yemen, and other countries, hoping to exploit a sectarian dynamic in these countries to attract followers. At the same time, sectarianism encourages internal divisions. The Islamic State's 2009 strategy document even quoted the Chinese military strategist and philosopher Sun Tzu, counseling the mujahideen to “make them always preoccupied with internal problems.”29

Ideology is tied in with legitimacy, and the Islamic State claims to be implementing Islamic law to justify its actions. When the group conquers a new area, it will often prohibit the possession and consumption of alcohol, force women to cover themselves completely, and otherwise engage in acts to show its religious bona fides. Strict implementation of traditional punishments such as amputations and beheadings reinforces this image and serves as a regular reminder to the population of the Islamic State's power.30

Yet, ideas have power that goes beyond organizational or strategic uses. The Islamic State from the start has often been zealous to the point of being counterproductive. In counsel that channeled the military strategist Carl von Clausewitz, a senior al-Qaida adviser advised Zarqawi that “policy must be dominant over militarism” (McCants, p. 13, quoting Attiyah abd al-Rahman, a senior al-Qaida figure who headed the group's efforts in Iran, among other duties). This adviser recognized how zealotry had destroyed past jihadist movements “with their own hands,” citing Algeria in the 1990s as an example. However, one of the Islamic State's post-Zarqawi leaders in Iraq in the last decade, Abu Ayyub al-Masri, led the organization down the road to disaster, in part because he clung to the belief that the Islamic State should be treated as a real state, even though at the time it controlled no territory. Suggestive of his disconnect from reality, al-Masri instructed his men to build pulpits for the Mahdi to ascend and ordered his commanders to immediately conquer Iraq, as the savior would be arriving soon. He also claimed that all who refused to bow before him—including other Islamist insurgent groups and Sunni tribal and religious figures—were apostates and targeted them for brutal punishment; in so doing, he turned many of these powerful figures against the jihadists (McCants, pp. 31–37). Such zealotry remains a constant issue. Today, for example, the Islamic State sometimes imposes smoking bans—a deeply unpopular move in a land of heavy smokers (Cockburn, p. 39).

Ideology has also shaped the Islamic State's military operations. The group fought hard to wrest the small Syrian village of Dabiq from Free Syrian Army fighters. It attributes the importance of the village to a saying of the Prophet Mohammad, who declared it the area where Muslims would defeat “the Romans” (a label now interpreted to mean the forces of the West) (McCants, p. 102). Conquering the village generated a recruiting bonanza for the Islamic State as well as a sense of ideological fulfillment. Similarly, ideology shapes the Islamic State's alliance strategy, or lack thereof. The Islamic State shares many enemies with other fighting groups in Iraq and Syria, not to mention the hostility its shares with Turkey and Saudi Arabia toward the Assad regime. Likeminded groups such as JN have cooperated in various ways with all these powers. Yet the Islamic State stands alone in refusing to cooperate with ideological enemies or groups that it believes should swear obedience.

The Islamic State's ideology, however, is broad and contradictory in its tenets, and many of its recruits are theologically illiterate.31 McCants, who in general stresses the ideological nature of the group, points out that “the State's scholars pick and choose scripture to suit their biases and desires” (McCants, p. 150). McCants also points out some of the group's contradictions: the Islamic State is cunning yet apocalyptic, puritanical yet willing to work with former secular Baathists and tribes, and so on (McCants, p. 154). Indeed, many followers join out of a sense of catharsis, adventure, desire for prestige, and community defense, using ideology to justify and add luster to these motives. The result is that the Islamic State can justify a wide range of actions with little pushback from its followers.

Perhaps the best example of this flexibility is the Islamic State's ruthless pragmatism with regard to the Syrian regime; the group is willing to cooperate by adhering to de facto cease-fires while still professing eternal enmity. And as mentioned earlier, both the Islamic State and the Assad regime fight moderate rebel groups such as the Free Syrian Army and JN. The Islamic State has also sold oil to the Syrian regime as well as to foes such as the Free Syrian Army and JN.32 For a highly ideological movement, the Islamic State is remarkably strategic.33

Building a State

When ideology conflicts with strategic necessity, the Islamic State's propaganda increasingly tries to portray its state as the fulfillment of prophecy. Doing so enables the group to attract recruits from the apocalyptic community while staying pragmatic.34

Much of the Islamic State's strategy rests on the classical state-building process outlined by Charles Tilly: “War made the state, and the state made war.”35 In contrast to al-Qaida, which stresses having a small vanguard lead in the Islamic community and believes that the failure of state building in Iraq showed that the time was not right for this ambitious endeavor, the Islamic State has tens of thousands of men under arms. It regularly expresses its goals as “enduring and expanding” (baqiya wa tatamaddad) and seeks to build a state in areas it controls and then use that control to expand the state ad infinitum. For all its fiery rhetoric, the Islamic State is building its state methodically, developing institutional structures, proselytizing, intimidating the population, and providing minimal services as it conquers territory.36

When the group goes into a new area, potential enemies—religious minorities, those who cooperate with governments it opposes, and so on—often flee, depriving the area of opposition figures. The Islamic State then imposes a brutal form of law and order. Many other militia groups in Iraq and Syria are less brutal but steal more, making them even more unpopular than the Islamic State and the latter look good by comparison. The Islamic State has often gained legitimacy by cracking down on these brigands after wresting areas from their control.37 In general, however, the group does not seek to win over the people, with one exception: after its debacle in Iraq, it now woos the region's tribes, courting them with money and gestures of respect (Warrick, p. 298).

The group also offers basic state-like services. It provides medical assistance, enforces price controls, creates courts and police forces, prods local municipal employees to return to work, and provides traffic officers; it has even created a consumer protection bureau (Stern and Berger, p. 114; Weiss and Hassan, pp. 232–233).38 The quality of these services and of the group's ability to govern is poor, but even limited services are valuable in war zones. In addition, the Islamic State rejects the assistance of other service providers, including international nongovernmental organizations, because they threaten its monopoly on service provision.39

The Islamic State also exploits the resources in areas it controls. It has seized much of Syria's oil and gas production and has sold wheat and water. It holds hostages for ransom and imposes taxes on the population it controls, generating millions of dollars per day.40 These resources enable the Islamic State to draw fighters from rival groups merely because it offers higher wages.41 In addition, the area's economic problems strengthen the group's recruiting ability, as impoverished Syrians and Iraqis join its ranks simply to put food on the table.42

The Islamic State allows, and even encourages, rape and sexual slavery to reward followers and gain recruits.43 Female prisoners are forced to become wives of foreign fighters; those from religious minorities often become sexual slaves.44

The Islamic State also proselytizes to solidify its control and attract new recruits. In areas it rules, it establishes training camps for boys to provide soldiers for its armies.45 Islamic State schools indoctrinate students on the group's religious vision.46

Control of territory becomes a recruiting device, which in turn enables further expansion. The Islamic State stresses the superior moral life and outright fun enjoyed by those who live in a true Islamic State, attracting not only male fighters but also women eager to marry them and raise families. Islamic State media depict graphic images of violence, but also Ferris wheels and the delivery of sweets to the elderly.47 One female jihadist posted a photo of an Oreo cheesecake she made lying next to a grenade,48 a neat combination of multiple propaganda streams.

At the same time, the Islamic State seeks to expand beyond its core areas in Iraq and Syria with help from the so-called provinces.49 Some of the process is bottom up, with the Islamic State's reputation attracting would-be followers in other countries, while in several cases—notably, Libya and Sinai—the Islamic State has sent emissaries to gain local support. In other instances, such as those of the Islamic State in Afghanistan and Pakistan, local rivalries led rebel leaders to split from the established movements, with the Islamic State being a convenient brand around which to rally potential followers. In accepting pledges of loyalty (bay'a) from other jihadist movements, the group is able to show momentum. As Charles Lister, a researcher on terrorism, writes: “Each wilayat [province] acts as an ink spot, gradually expanding outwards through violence and social activities.”50 Eventually the ink spots merge together, further expanding the control of the would-be state. This international presence also enhances the Islamic State's legitimacy and boosts the morale of its followers.

To the surprise of many observers, terror and brutality serve state-building purposes. The jihadist movement was never a stranger to this: in Algeria in the 1990s, jihadist organizations would disembowel pregnant women; meanwhile in the Balkans, Bosnian jihadists played soccer with a decapitated head (Stern and Berger, p. 2).51 Zawahiri warned Zarqawi to avoid beheadings and other measures that might alienate the masses, even though such actions might thrill “zealous young men” (McCants, p. 13). Subsequent al-Qaida affiliates in Yemen and in Syria would try to govern well and court the population, rather than forbid popular practices such as smoking and sports. Their goal was to avoid painting a bull's eye on their organization by creating a state that the United States and its allies could target. As McCants comments, “If you didn't know he ran the world's most notorious terrorist organization, you'd think Bin Laden was an officer working for the United States Agency for International Development” (McCants, p. 66).

In contrast to Zawahiri's warning, violence has proven a recruiting boon for the Islamic State, giving it a brutal, tough brand that both plays well with young men and helps the Islamic State attract fighters from around the world. In addition, brutality helps the Islamic State stay in power. Most of those under its rule have witnessed a beheading or other harsh punishment.52 Often locals take advantage of the Islamic State's presence to settle scores with those to whom they owe money or otherwise have a grievance: they accuse them of being spies, and the Islamic State kills them.53 As one journalistic account argues, “By publicly beheading and crucifying people even suspected of disloyalty, the militants have created a culture of horror and fear that has made it virtually impossible for people to rise up against them.”54

The Islamic State's successful use of high levels of repression is not unique; and to the extent that a strong government is more important than a good government, extensive repression can prevent an uprising.55 For example, as Yuri Zhukov contends: Russia's long history suggests that “repression works, but not in moderation.”56 Stathis Kalyvas, a scholar of civil wars who is critical of indiscriminate violence, also accepts that massive violence can reduce insurgent activity, a view supported by several other studies.57 Effective repression could compel individuals not to support a rebellion, even if they sympathized with the insurgents' anti-regime agenda.58 Repression shrinks the political space by allowing potential insurgents fewer opportunities to organize and making the costs of joining much higher, which in turn makes it difficult for them to gain the critical mass needed to sustain the fight and triumph.59

In its foreign policy, the proto-state is very much a revolutionary one. As Stephen Walt wrote, such revolutionary states are highly aggressive, incite fears among their neighbors, and feel constantly vulnerable. They use their ideologies to stir up dissent in neighboring countries and also alarm them by threatening their legitimacy; and through their bellicose rhetoric, they can provoke interventions. The Islamic State, like many revolutionary states, is eager for war and alarms its neighbors and the international community with its rhetoric and support for terrorists and militants throughout the Middle East.60

The Islamic State uses terrorism, but describing it as a terrorist group is misleading: guerrilla and conventional war are often more important than terrorism for the group.61 The Islamic State fights on multiple levels. It uses terrorism against its foes, but it also infiltrates rivals and seizes power from within. Moreover, it fights in a conventional manner “with a professional acumen that has impressed members of the U.S. military” (Weiss and Hassan, p. xv). When it does use terrorism, it is often more as a quasi-state sponsor of terrorism than as a traditional terrorist group.62

For the Islamic State, terrorism is part of its civil war strategy. As the late jihadist strategist Abu Bakr Naji advised, groups such as the Islamic State should carry out “vexation operations” against enemy homelands in neighboring states.63 Such operations compel enemies to disperse their forces, essentially playing defense, and deplete their resources. In addition, terrorism serves as a deterrent, forcing enemies to “pay the price” and, in so doing, perhaps hesitate to attack in the future.64 At the same time, the Islamic State can play a sectarian or an anti-Western card using terrorism, gaining access to new recruits by fomenting divisions and religious hatred.

Indeed, for the Islamic State much of what is typically considered terrorism, such as suicide bombings, is employed as part of war, but the group also uses warfare to produce political and psychological effects as other groups might use terrorism.65 In a military operation, suicide bombers might be deployed to breach enemy positions, or an enemy commander might be assassinated and decapitated. Images of such events are released instantly on Twitter to instill fear among enemy soldiers. Operations are often filmed and disseminated to potential recruits, leading to massive enlistments: the Islamic State might lose hundreds in a battle, but propaganda from that battle might attract thousands more.66 In general, the Islamic State's attacks on police and military recruits off the battlefield have weakened the Iraqi government, hindered recruitment, drained government resources, and created security vacuums—all of which makes it easier for the Islamic State to gain recruits and advance its interests (McCants, pp. 80–81).

Terrorism also is an option if traditional military means fail or are unavailable. The Islamic State, for example, cannot engage in guerrilla or conventional warfare in Europe or the United States, so terrorism is a means of striking these targets. In Iraq and Syria, the Islamic State had lost key border towns and large amounts of territory before the Paris attacks, suggesting that it sought to offset losses with successful attacks elsewhere.67 As terrorism expert Clint Watts points out, extremist groups that lose territory “will be highly incentivized to turn to terrorist operations” that have low costs but a high profile.68

Organizational Strengths and Weaknesses

The Islamic State is a formidable adversary. Yet its many strengths can be overstated, as the group has considerable weaknesses as we well.


The Islamic State's organizational strengths include its ability to conduct a full spectrum of operations, its powerful mix of former Iraqi security officials and foreign fighters, its skilled use of the media and propaganda, and the weakness of its foes. Together, these factors have enabled the Islamic State to create an image of itself as dynamic and victorious, an image that helps its recruitment efforts and otherwise enhances its power.

The Islamic State has proven able to operate along the spectrum of activity identified by Chinese leader Mao Zedong as the key to rebel success: organizing its supporters, building institutions, and creating base areas in preparation for conflict; expanding through terror and limited guerrilla attacks; and then conducting conventional military operations. This flexibility has enabled it to survive crushing defeats and expand quickly when opportunities presented themselves.69 Zarqawi's organization began as a small terrorist group, using high-profile attacks against Shiites and international targets to undermine the Iraqi government and make a name for itself. Later it would embrace insurgency, destabilizing and eventually replacing local governments. Next, it tried unsuccessfully to rule in Iraq; when this failed, it returned to insurgency and then survived using terrorism when it was almost wiped out in Iraq by 2010. As local conditions changed, it exploited them by returning to guerrilla war and eventually conventional military operations.

To function along this spectrum, the Islamic State incorporated former Baathist military and security officers into the group, bringing much-needed organizational skills to the movement (Stern and Berger, p. 38). This alliance began right after the U.S. invasion of Iraq, when the jihadists and Baathist officers worked together to build bombs and conduct attacks, and Baghdadi renewed it after he came to power.70 The Islamic State also seeks out highly motivated recruits. According to one report, its training course has a survival rate of only 50 percent, in part because it uses live ammunition (and, perhaps, because of the low quality of some recruits).71

Foreign fighters have proven an important resource. When the Islamic State and JN split, perhaps 60 percent of the foreign fighters went to the Islamic State. This percentage would grow dramatically in response to the Islamic State's declaration of a caliphate.72 By the end of 2015, the group had attracted about 30,000 foreign Muslim fighters. Most were from the Muslim world, but about 5,000 came from the West; some were motivated by zeal and a desire for martyrdom, but many by a sense of adventure.73 Foreign fighters have often proved the most zealous of the group's fighters—and the most expendable—providing many of its suicide bombers, which the Islamic State uses on an industrial scale.74 As discussed below, foreign fighters also offer capabilities for strikes on the West.

The Islamic State is also skilled in the use of media and propaganda—far more so than groups such as al-Qaida. From the start, Zarqawi's group stressed images of action and violence, in contrast to bin Laden's and then Zawahiri's tedious sermonizing.75 In its propaganda, the Islamic State features a mix of ultraviolence and good governance practices. Some videos stress combat and beheadings; others display the horrors that it will inflict on its enemies; and still others highlight access to nursing homes, health care, and other services for the faithful. Jihad, in Islamic State propaganda, is glamorous, fun, and meaningful, and the jihadists who heed the call are brave, proud, and cool champions of the faith (Stern and Berger, pp. 68–87).

Taking advantage of the technological savvy of its younger members, the Islamic State uses YouTube, Facebook, Twitter, WhatsApp, Ask.Fm, and other forms of social media to disseminate its message and recruit new members. In 2015 there were tens of thousands of pro-Islamic State Twitter accounts online, of which 3,000 were in English.76 Many recruits, especially high-profile ones, turn over their social media accounts to the group.77 Part of the success of the Islamic State reflects a more permissive internet environment, as governments in 2014 and 2015 were less restrictive than they had been at the end of the last decade.78 Today it is almost impossible for a young Muslim either in the West or in the Muslim world not to see jihadi propaganda.

In addition, the Islamic State floats trial balloons via social media to make sure that its eventual decisions will be popular. Disseminating acts of spectacular violence is a way of fomenting divisions, weakening the enemy, and recruiting. Zarqawi made his name in Iraq in part by disseminating videos that showed him beheading hostages. His Islamic State successors would make hundreds of videos showing the execution of Iraqis and Kurds, some of whom they would later crucify (Stern and Berger, p. 4). Such brutality increases ethnic and sectarian hatred, but it also appeals to many potential recruits. Moreover, graphic images of violence dishearten enemies, making them more likely to flee.79

One of the Islamic State's biggest strengths is the weakness and even disinterest of its chief adversaries. Even before the emergence of the Islamic State, the Syrian and Iraqi governments' rule over remote Sunni areas was poor. Today, the Islamic State may be both less corrupt and more efficient in providing services than its recognized state predecessors.80 In their respective civil wars, the Syrian and Iraqi governments prioritized other foes. For the Assad regime, the biggest threat has been the moderate Syrian opposition: the regime believes that if it can paint its foes as radicals, then it will gain international support. Similarly, the sectarian agenda that the will regime has used to rally its own supporters plays into the Islamic State's hands. At the substate level, many of its Syrian opposition rivals are corrupt and weak, and the Islamic State has repeatedly been able to take their weapons (Cockburn, p. 3). U.S. allies such as Turkey and Saudi Arabia oppose the Islamic State, but they prioritize fighting the Assad regime, which they consider a far more dangerous foe.81 Iraqi and Syrian Kurds oppose the Islamic State, but their focus is more on securing what they consider their own territory than on bringing the war to the Islamic State's Sunni Arab heartlands.

Similar problems are also present in Iraq. When the Islamic State took Mosul in June 2014, perhaps 30,000 well-armed Iraqi forces fled the city in the face of maybe 1,000 Islamic State fighters, leaving behind massive amounts of equipment, including Abrams tanks as well as small arms and ammunition.82 When asked about why the Iraqi military performed so dismally, one retired general responded: “Corruption! Corruption! Corruption!” (quoted in Cockburn, p. 64). The Islamic State's expansion occurred in part because Iraq's military forces comprised primarily Shiites, who had little interest in defending local Sunnis, many of whom viewed them with hostility and contempt (Weiss and Hassan, p. 45). Thus in Sunni areas such as Mosul, residents often regarded the army as an instrument of an Iranian puppet regime (Cockburn, p. 16). The Iraqi officers did not command the respect of their troops and they lacked professionalism; when they fled the battlefield, their troops quickly followed.

The United States is directly targeting the Islamic State over other declared enemies such as the Assad regime and has assembled a coalition of more than sixty countries to defeat the group. Yet few of these countries provide significant support in Iraq and Syria: as of November 2015, the United States provided almost 80 percent of the sorties. In addition, the overall strike rate is low—far lower than it was in Libya during the war to oust Muammar al-Qaddafi.83 The Obama administration has deployed forces to train the Iraqi and Syrian opposition, but it has hesitated to put in significant numbers of U.S. ground troops—hesitation shared by all U.S. allies. And though U.S. air power has halted Islamic State operations and contributed to limited setbacks, the opposition on the ground has made only limited progress in rolling back the Islamic State.84

Victory on the battlefield has been another source of the Islamic State's overall success. As the organization has won battles, it has attracted defectors from other groups and more foreign fighters, further strengthening it for the next battle. A United Nations official noted that Syrian rebels defect to the Islamic State because “[t]hey see it as better, these guys are strong, these guys are winning battles, they were taking money, they can train us” (Cockburn, p. xviii). By conquering territory, the group gains more resources and prestige, which enable it to attract more local and foreign fighters. Similarly, by defying Russian, U.S., and other foreign pressure, it strengthens its reputation as a strong, proud organization that appeals to many potential recruits. This reputation helps it attract better fighters who are motivated by prestige and honor rather than just a paycheck.


Despite its considerable strengths, the Islamic State has a variety of weaknesses. Many of these weaknesses, however, are more latent than actual: they are more likely to manifest over time or in response to effective international intervention.

In essence, the Islamic State is turning many standard U.S. assumptions about counterinsurgency on their head, particularly the assumption that local governments should attempt to “win the hearts, minds, and acquiescence of the population.”85 The Islamic State cares little about gaining popular support, in contrast to what U.S. counterinsurgency doctrine and al-Qaida teachings would endorse. Rather than trying to win hearts and minds, the Islamic State tries to intimidate those it rules into obedience. Co-optation is limited to tribal figures and others of strategic importance. But even then, when a tribal revolt occurs, as happened in Iraq in 2014 when the Bu Nimr and Sheitat tribes rebelled in Anbar Province, the Islamic State will not hesitate to expel or execute thousands of tribal members.86

The brutality of the Islamic State suppresses opposition, but it also produces anger and resentment that can flare up if the group lifts its repressive measures. The Islamic State executes internal critics and has killed hundreds of fighters to stifle dissent. Its systematic use of rape and sexual slavery is a highrisk, morally repellent strategy, as is its practice of forcing local Sunni females into unwanted marriages. Members of al-Qaida in Iraq regularly raped Iraqi women, turning the local population against the group to devastating effect (Weiss and Hassan, p. 69). Jeremy Weinstein argues that rape and other forms of indiscipline can make a population hostile toward rebels, hurting them in the long term.87 As such, the Islamic State faces vulnerabilities should its monopoly on violence be threatened.

The Islamic State also faces military limits. The group has tens of thousands of fighters under arms, but it is still smaller than the combined number of moderate Syrian opposition forces. This disparity is especially large when one takes into account local enemies such as Syrian and Iraqi Kurds, the Lebanese Hezbollah, Jabhat al-Nusra, and the Iraqi government forces. In Iraq, in particular, Shiite militant groups number in the thousands and often represent more fighting power than the Iraqi army. Gone are the days when the Islamic State's forces could sweep across Iraq. Faced with U.S. air power and limited, but nonetheless real, local forces on the ground, it has become more defensive and opportunistic.88

The group is also taking considerable casualties: an anonymous source in the Pentagon claimed in October 2015 that 20,000 Islamic State fighters have died since the U.S. intervention began.89 They include members considered in some way suspect and therefore expendable. The Islamic State has been known to send such individuals to the frontlines or order them to become suicide bombers.90

Foreign fighters are a vulnerability as well as a strength. They receive free housing, medical care, and food; are given greater access to females for sex; and are paid more than locals.91 Their superior status often alienates locals, however, lowering morale and creating broad resentment that could be exploited. As Peter Neumann argues, “[I]n the long term, they will turn out to be a burden.”92 Many among the foreign fighters do not speak Arabic, making it hard to integrate them into the Islamic State's military forces. As a result, the group has created distinct units for francophone and English-speaking cadre, an action that may hinder command and control.93 Many of the group's foreign recruits are poorly trained or simply incompetent. Because the Islamic State believes that newcomers might be providing intelligence to enable U.S. air strikes, it spends considerable time and effort monitoring and vetting them.94

The Islamic State's financial model is also vulnerable. As mentioned earlier, to maintain its grip on power, the group provides basic social services and usually offers higher wages to fighters than do its rivals. In addition, it provides financial support for the families of fighters, including the deceased. The cost is quite high. When the group suffered setbacks in Iraq at the end of the last decade, it found that it was losing revenue at the same time that the cost of paying the families of the deceased was increasing, making it desperate for cash.95

Nor is the Islamic State likely to succeed as a state beyond the most basic level. Repelled by the group's barbarity and harsh restrictions, skilled technicians have fled Islamic State lands.96 The pan-Islamic identity is real, but it is questionable whether this can consistently overcome national and regional divisions. The group depends heavily on taxing locals and extorting money, but both its economic policies and constant war-making bode poorly for long-term economic development. Indeed, as Zawahiri warned, by creating a state it has made itself a target, enabling foreign powers to strike it more effectively while depriving it of economic resources.

The Islamic State's biggest weakness, however, is its combined intolerance and ambition. The group is fighting on multiple fronts, and its actions invite more enemies. When the group rampaged across Iraq, Iran and the United States cooperated to replace Prime Minister Maliki with Haider al-Abadi in the hopes that he would be a less polarizing figure. As Iraqis say, “[T]he Iranians and the Americans shout at each other over the table but shake hands under it” (Cockburn, p. xv). It proved relatively easy for the Obama administration to assemble a broad coalition against the group. The Islamic State has also failed to work with other Sunni rebel groups, let alone ethnic or religious minorities, against shared foes. When Russia intervened in Syria, it focused on fighting moderate opposition forces that also oppose the Islamic State. But after the Islamic State brought down a Russian airplane in the group's Sinai province on October 31, 2015, killing all 224 people aboard, Russia diverted resources to bomb Islamic State positions.

So far these foes have devoted only limited resources to fighting the Islamic State. Many prioritize other interests, and they all have limits to their power. For example, the United States does not want to deploy large numbers of U.S. ground forces or work with Islamic State enemies such as Iran, the murderous Assad regime, or terrorist groups such as the Lebanese Hezbollah and Jabhat al-Nusra; Washington is also leery of Iranian-backed Shiite militias in Iraq, which have proven more effective than the Iraqi army in many battles. Sunnis in the parts of Iraq and Syria where the Islamic State holds sway also see these militias as murderous outsiders. Kurds in Iraq and Syria have proven formidable foes, but have concentrated their fighting on defending Kurdish-populated areas and would be seen as outside armies in Sunni Arab regions where the Islamic State is strongest. Therefore, the Islamic State's list of enemies is long, but the current threat to the group remains limited.

The Islamic State Threat

The Islamic State is a danger to the United States and its allies. Its greatest threat, however, is to the Middle East and U.S. interests there.


The Islamic State has a long list of proclaimed enemies. The “infidel” United States and several European countries are on the list, but so too are “apostate” Gulf Arab states as well as the Alawi regime in Syria and the Shiite governments in Iran and Iraq. Muslim minorities are particularly suspect, as are supposedly traitorous Sunnis who cooperate with the Islamic State's enemies. Cooperation is broadly defined: simply having a relative who was drafted into the Syrian army, for example, makes one an enemy of the Islamic State.97 Similarly, any country or group that does not bow down to the Islamic State is, by definition, illegitimate.

Yet all enemies are not created equal. Baghdadi undoubtedly loathes the United States, and woe to any American who falls into the Islamic State's clutches, but the group's resources are dedicated foremost to local and regional enemies—the “near enemy,” as jihadists would describe it. Zarqawi used to declare, “The way to Palestine is through Amman” (quoted in Warrick, p. 65), and this emphasis on consolidating power locally before expanding remains true today. A particular concern is the enemy within: disloyal Sunnis are at the top of the pyramid, with Muslim minorities also ranking high. When he was fighting exclusively in Iraq, Baghdadi declared that fighting the Shiites “is more of a priority than fighting the Americans” (quoted in Weiss and Hassan, p. 119). The Islamic State has fought more battles against other jihadists and the Free Syrian Army than it has against the Alawi regime, let alone Israel.98

Al-Qaida, in contrast, famously emphasized the so-called far enemy—the United States and Europe—which bin Laden argued was the “head of the snake.”99 Although Zarqawi advanced al-Qaida's goals of killing Americans by targeting them in Iraq, he and bin Laden differed over the Shiites, whom Zarqawi referred to as “servants of the Antichrist,” and whose subjugation he believed should be the jihadists' top priority (McCants, p. 10). Bin Laden, in contrast, saw the Shiites as simply ignorant and called for focusing first on the United States. In general, Inspire—the English-language journal put out by al-Qaida in the Arabian Peninsula—emphasizes attacks in the West, whereas Dabiq—the Islamic State's English-language propaganda organ—voices support for attacks on the West, but primarily calls on Muslims to travel to Syria or other lands controlled by the Islamic State and its provinces to fight on behalf of the Islamic State. Baghdadi himself rarely mentions the West in his remarks.100

This prioritization is in part based on the Islamic State's sound judgment of its foes' staying power. At the end of 2009, when the organization was weak, Iraqi jihadists circulated a document entitled “Strategic Plan for Reinforcing the Political Position of the Islamic State of Iraq.”101 The plan presciently noted, “[T]he situation will be strong politically and militarily” after the Americans' imminent departure. The Iraqi jihadists argued, with some degree of accuracy, that the United States is a more temporary and transient enemy than the Shiites and disloyal Sunnis. Zarqawi believed that Americans are “the most cowardly of God's creatures” who would eventually leave Iraq (Warrick, p. 126).

Al-Qaida is a top enemy: yet the Islamic State cannot directly admit this. As scholar Lina Khatib argues, the Islamic State is “in an existential battle with al-Qaeda.” The two compete for recruits, funds, and especially legitimacy. The Islamic State, as a supposed state, demands obedience from groups such as al-Qaida and Jabhat al-Nusra. It also claims that it, not Zawahiri, is the inheritor of bin Laden's mantle. To destroy Jabhat al-Nusra, it has used car bombs and kidnappings as well as military operations.102


When the Islamic State first emerged, U.S. leaders were initially dismissive, emphasizing instead the continued al-Qaida threat. As President Obama noted, “if a jayvee team puts on Lakers uniforms that doesn't make them Kobe Bryant.”103 As the Islamic State swept through Iraq, slaughtering and enslaving Yazidis and retaking the country's second-largest city, Mosul, and much of the Sunni-populated West, the perceived threat grew enough to merit limited intervention. After the 2015 Paris and San Bernadino attacks, the perceived threat grew even more.104

The biggest threat the Islamic State poses is to the Muslim world. The return of the group to Iraq has thrust the country back into civil war, destabilizing a major oil producer and exacerbating an already-poor humanitarian situation. As of December 2015, 40,000 Iraqis had died as a result of violence.105 The group is also attacking in Saudi Arabia, Lebanon, Turkey, and Jordan, risking greater instability in all these countries, some of which are major U.S. allies.106 So far, Lebanon is most at risk, but it was already fragile.107 Saudi Arabia and Turkey, the United States' two most important allies in the region, have been relatively stable in the face of spillover risks ranging from terrorism and radicalization to the flow refugees.108

The Islamic State is also disruptive beyond its immediate neighborhood, having a brand that is popular around the Muslim world. On November 10, 2014, it declared that groups in Algeria, Libya, Saudi Arabia, Sinai, and Yemen were provinces in the new caliphate. Boko Haram, the powerful Nigerian group, would also later declare loyalty, as would factions of the Taliban and al-Shabaab and groups as far away as the Philippines. Such provinces bring prestige, prove that the Islamic State is expanding, and give it greater reach. And as mentioned earlier, the Islamic State's Sinai affiliate downed a Russian airliner over the Sinai Peninsula in October 2015. Taking on the Islamic State label gives groups a valuable brand and allows factions within al-Qaida affiliates to assert their independence.

The Islamic State's brand is a brutal one, even by civil war standards, and more gruesome tactics, greater sectarian tension, kidnappings, attacks on Western targets in the local theaters, and rape and sexual slavery are likely to spread. In addition, by providing financial and fighter support to select groups, the Islamic State is making them more capable. As a result, its model and its reach are spreading throughout the Muslim world, particularly to war zones that already have an active jihadist presence.

Questions continue to swirl around the influence of the so-called provinces. In contrast to al-Qaida, where joining as an affiliate led to limited changes in tactics and targeting as well as a sharing of networks, the operational impact of being a province is not clear.109 Local provinces have embraced beheadings and attacked religious minorities, but the command and control exerted by the core leadership is often mixed, with some provinces such as Libya being close to the core but others such as Nigeria less coordinated.110

The Islamic State is also creating schisms in the jihadist movement, with rival groups in places such as Afghanistan and Libya using the Islamic State label to gain legitimacy against other jihadist foes. The positive news is that these divisions generally weaken the jihadist movement. The cost, of course, is more bloodshed as these groups war against one another. The Taliban, for example, has warred against its former commanders who now claim loyalty to the Islamic State.111

Outside powers are particularly concerned about the risk of international terrorism involving foreign fighters. Foreign fighters associated with the Islamic State and other groups undergo several changes that make them more dangerous. They often begin as callow youths looking for adventure, but return as combat veterans who embrace a more radical worldview and disassociate themselves from their former friends and family. The Federal Bureau of Investigation director, James Comey, stated: “All of us with a memory of the ‘80s and ‘90s saw the line drawn from Afghanistan in the ‘80s and ‘90s to Sept. 11.” He then warned, “We see Syria as that, but an order of magnitude worse in a couple of respects.”112 The 2015 Paris attacks, where several of the bombers had fought in Syria and plotted from there, seem to confirm these fears.113

Although the Middle East remains the Islamic State's primary theater of operations, international terrorism is also a legitimate concern, as the Paris attacks demonstrate. In 2015 there were more than twice as many Islamic State–linked plots in the West as there were in 2014.114 The threat can easily be exaggerated, however. One study of jihadi plots in Europe from 2011 to mid2015 (before the attacks in Paris) found that the Islamic State's attacks were primarily inspirational, with the central organization not mounting the attacks directly. Although many Europeans went to fight in Syria, the pre-Paris rate of foreign fighters coming home and becoming terrorists was roughly 1 in 360—a far smaller proportion than in past conflicts such as Afghanistan.115 After the U.S. invasion of Iraq and other conflicts, fears of foreign fighters committing terrorism grew, but no huge increase occurred.116 Since the September 11 attacks (even after the 2015 San Bernadino attack), right-wing groups have killed more people in the United States than have jihadist groups.117

Past experience and the Syrian civil war itself indicate a range of mitigating factors that reduce the potential foreign fighter threat from those who have gone to Syria. Some volunteers, especially the most committed, blow themselves up in suicide attacks or die in battle. Others go from jihad to jihad, never leaving the conflict zone. Some fighters quickly become disillusioned and abandon their jihadist fantasies. In addition, many of those who return are not interested in attacking their home countries. Others are arrested or disrupted by security services, which are on guard against the danger and preemptively arrest many returnees.118 The Paris mastermind and many of the other attackers, for example, were well known to European security services, and some had been briefly detained—missed opportunities for intelligence collection and disruption were rife.119 The decision to go abroad to fight, particularly given the tendency of foreign jihadists to broadcast their every move on Twitter and Facebook—gives security services many opportunities to detect potential terrorists.120

More difficult to stop are terrorists who are inspired by the Islamic State but who do not have a direct organizational link—so-called lone wolves. Not everyone can perform hijra and travel to Iraq and Syria, but many still want to fight. In addition, the Islamic State seeks to frighten its foes with the threat of constant attacks. Therefore, after the initial 2014 U.S. air strikes on Islamic State forces in Iraq, the group called on Muslims in the West to “strike their police, security, and intelligence members.” Its propaganda exhorted, “Smash his head with a rock, or slaughter him with a knife, or run him over with your car, or throw him down from a high place, or choke him, or poison him.”121 As of December 2015, perhaps 250 Americans had joined the Islamic State; 71 people in the United States had been arrested for criminal acts related to Islamic State support, with 2015 seeing more arrests than any year since the September 11 attacks.122 Lone wolves serve several purposes. They offer an efficient way to sow fear without devoting resources to developing a transnational operational network. In addition, they stretch the resources of security services and provoke constant anxieties about attacks.

Some terrorist attacks are therefore inevitable. Foreign fighters or others known to security services might slip through the web, or lone wolves such as the San Bernadino killers will follow through with an attack. Predicting the number of attacks is difficult, as chance plays a significant role, but the United States and its allies can expect a significant number of attempts and at least a few successes in the years to come.


The books reviewed in the essay offer valuable insights into the rise of the Islamic State and its growing role in Syria, Iraq, and beyond. The Islamic State is an evolving organization, however, and it has changed since the time of publication of these works: the books do not address the implications of the 2015 Paris attacks, the growth of Islamic State provinces in other Muslim countries, and other important changes. Moreover, they do not provide a clear strategy for defeating the Islamic State. The remainder of this essay offers some recommendations for containing and neutralizing the group.

In the years since the September 11 attacks, the United States has developed a powerful counterterrorism machine involving intelligence cooperation, drone strikes, and other means that have hindered Al-Qaida's attempt to exploit safe havens and greatly reduced its capacity to conduct international terrorist attacks.123 Indeed, the decade after the September 11 attacks proved remarkably safe in terms of actual terrorist attacks on the U.S. homeland.124

This anti-al-Qaida model does not always apply to fighting the Islamic State—in large part because of its many differences with al-Qaida and its emphasis on guerrilla war and conventional operations, not just terrorism. Drone strikes, for example, are most effective when the number of leaders and cadre being hunted is limited: the Islamic State, however, has tens of thousands of fighters, and the loss of even dozens of its leaders to drones is probably far less than its losses in regular combat with local foes. International intelligence cooperation is vital to fighting the Islamic State's global network, but it will do little against the group's core, which operates from its sanctuary in Syria and Iraq, where the group controls territory. So far at least, the group's genius for making enemies has not proven its undoing. France, Iran, Russia, Saudi Arabia, Turkey, the United States, and the Syrian and Iraqi regimes as well as numerous substate actors all have good reason to oppose the Islamic State, but they are not devoting massive resources to its defeat. In 2015 President Obama stated that the U.S. goal was to “degrade and ultimately destroy it through a comprehensive and sustained counterterrorism strategy.” And in 2016 he declared, “We have to take them out.”125 This challenge can be thought of as twofold: a local one in Iraq and Syria and a global one focused on Islamic State provinces and terrorism in the West.


The Islamic State's center of gravity is its base in Iraq and Syria and its performance as a state. Part of the Islamic State's recruitment pitch is that the group is winning: it is killing unbelievers, battling infidel powers, and establishing an Islamic state on the ground. Therefore, defeating the group's message depends in part on creating a perception that it is losing. In addition, for the Paris attack the group used Syria as a haven to plan the strikes, and Iraq and Syria remain the nexus of the foreign fighter problem in general.126

In theory, battling the Islamic State in Iraq and Syria is a simple and straightforward task—but the simplest things can be very difficult to achieve. In fighting the Islamic State, the United States has relied on a mix of air strikes and support for local allies, including from Iraqi and Syrian Kurds, the moderate Syrian opposition, and the Iraqi government. As of early 2016, the U.S. approach had neither failed nor succeeded. After the Islamic State had rampaged across Iraq in the summer of 2014, air strikes forced Islamic State fighters to end their semi-conventional warfare and adopt more guerrilla tactics: they no longer are able to launch swift knockout blows against their enemies (Cockburn, p. xii). Indeed, by the end of 2015 the Islamic State had lost up to 40 percent of its territory in Iraq from its 2014 peak strength as well as much of its oil infrastructure and heavy forces.127

Despite these losses, the Islamic State may believe that it can survive the international campaign against it. After the 2014 burning to death of a Jordanian pilot and the 2015 Paris attacks, Jordan and France, respectively, increased their number of air strikes against the group—but not for long. Nor did they dramatically change the local balance of power. Russia temporarily stepped up its attacks after the Islamic State's downing of a Russian aircraft in Sinai province, but to little overall effect. Similarly, by the end of 2015 the Islamic State had weathered more than a year of U.S. air strikes, taking losses but enduring nonetheless.128 It may also believe that the deployment of Western ground troops will fulfill its apocalyptic vision and attract more recruits.129 Foreign fighters continued to flow into Syria as of early 2016, enabling the Islamic State to replace lost cadre.130

Part of the problem in defeating the Islamic State lies with the limits of air power. On the positive side, air power acts as a force multiplier. Air power can effectively strike fixed targets such as arms depots and military headquarters. It can also devastate massed enemy forces and vehicles, making it hard for the Islamic State to gather large numbers of forces together to strike across distances or shift forces on the battlefield. When combined with precise intelligence, air power can also be used to strike the Islamic State's leadership. For example, the United States killed Fadhil Ahmed al-Hayyali, perhaps the Islamic State's number-two leader, in an air strike in Mosul. According to U.S. officials, in December 2015 such strikes killed ten Islamic State leaders including some linked to the Paris attacks and attacks on the West in general.131

To reach the next level of effectiveness, however, air power needs to be combined with operations by allied forces on the ground.132 Airplanes, of course, cannot occupy territory: if the Islamic State is successfully pushed back, some other force needs to fill the void. To avoid air strikes, the Islamic State might scatter its forces or resort to guerrilla warfare—but this would prove disastrous for its effort to build a state, as long as a strong opponent pushed through on the ground and captured its key cities and bases.

The competence of U.S. tribal allies in Iraq and parts of the Syrian opposition to conduct such a ground offensive and occupy territory in the long term is questionable. In Syria the moderate opposition, when unified, can effectively combat the Islamic State, but the opposition remains divided into dozens of smaller groups that usually coordinate in an ad hoc way. In both Syria and Iraq, despite years of U.S. training, local forces have proven that on their own they are no match for the Islamic State. At the substate level, some of the group's foes in Syria such as Jabhat al-Nusra and Hezbollah are strong, but in Iraq many local foes are divided internally and have no loyalty to the central government. Some among Iraq's Sunnis are willing to fight the Islamic State, but they do not want to be a national force or have national forces in areas they control (Weiss and Hassan, p. 45). The Kurds focus their fighting on Kurdish parts of Iraq and Syria. None of these local actors has national appeal. Therefore, although they can conduct effective operations in their tribal zone or ethnic areas, their ability to push back more comprehensively is limited by their more parochial desires and limited appeal. To create another tribal revolt or popular uprising against the Islamic State, as the United States did against al-Qaida in Iraq, U.S. or other serious protection is necessary—and that is unlikely.

Without strong local allies, air power becomes far less effective. Without accurate, local intelligence, air strikes can kill innocent civilians. Such strikes have led some tribes in eastern Syria to move closer to the Islamic State.133 Air strikes cannot stop the Islamic State or other groups from using roving bands to infiltrate areas and kill people, nor can bombings conquer territory. Without competent ground forces to call in and direct strikes, it is harder to sustain a rapid pace of attacks during battles. Although killing Islamic State leaders disrupts the group's command and control and forces its leaders deeper underground, the group has many leaders and has proven that it can weather the campaign. It is institutionalized, not personalized, and as such leadership decapitation is less effective.134

Even if the Islamic State is pushed back from territory it holds, it is not clear who will fill the void. The Islamic State's skill in moving along the Maoist spectrum suggests that the group would use terrorism and guerrilla war to harass occupying forces and try to regroup, as it did in Iraq after 2010. Any military presence would have to stay for years, to bolster a sound local government that can impose order and provide services—a combination that for now appears unlikely. In the short term, the Assad regime might move in, or more chaos might result. It is possible that another Islamic State–like group might fill the void. So defeating the Islamic State does not guarantee stability in the region or an end to its terrorism. Nor is it clear that sectarian and communal genies can be put back in the bottle. As Cockburn argues, in Iraq “the battle lines among Kurd, Sunni, and Shia are now too stark and embittered” (Cockburn, p. xiv).

The good news is that there are limits to the Islamic State's local expansion. Militarily, it has had far more trouble when it has tried to operate outside Sunni Arab areas, and the mix of U.S. air power and local forces has dealt it significant, though hardly mortal, blows on the battlefield. In addition, the would-be state is likely to do poorly economically, which may alienate supporters and challenge its claims to legitimacy. Indeed, no less an expert than Osama bin Laden argued that locals are likely to expect too much of their state and that jihadists cannot live up to those expectations.135 Therefore, containing the Islamic State through some variant of existing policies can work; and since intervening, the United States has pushed back the Islamic State out of parts of Iraq. These efforts limit but do not solve the problem.


Trying to contain or defeat the Islamic State in Iraq and Syria addresses only part of the problem. And if the Islamic State cannot be immediately defeated, then its ability to work with its provinces and international supporters will continue. However, at least some elements of the U.S. strategy that proved effective against al-Qaida are likely to also bear fruit vis-à-vis the Islamic State.

Going after the Islamic State's command and control is vital. To manage its global presence, the group needs to communicate and direct its affiliate organizations. Doing so creates vulnerabilities, however, and thus enables targeting.136 The United States proved able to disrupt al-Qaida's ability to communicate with its affiliates in similar circumstances.

The United States and its allies can also target the Islamic State's worldwide networks and loosely organized supporters. Aggressive intelligence campaigns and broad sharing of information can reveal many networks. True security against lone wolves is impossible, as they have a limited intelligence signature. Such individuals, however, are usually less competent and less lethal: it is no accident that the successful 2015 attacks in Europe were undertaken by individuals who received training from groups in the Middle East.137

The United States will also want to provide support for governments and groups fighting the Islamic State provinces. This support must be selective, as some of these provinces are not a direct threat to the United States and its allies. In addition, as the U.S. experience since the September 11 attacks has shown, security cooperation in the name of counterterrorism often fails or achieves only limited results given different interests among partners, corruption, and limited capacity, among other challenges.138

Another step is to try to weaken the narrative the Islamic State champions, though this will prove difficult. U.S. government campaigns in shaping opinion in the Muslim world have repeatedly failed,139 but the United States can try to use diplomacy to convince allies to act. Saudi Arabia, in particular, is fanning the fires of sectarianism (Cockburn, p. 99). The United States has had at best limited success in convincing the Saudis to change their position, particularly when it concerns issues related to domestic politics. Nevertheless, the United States should continue to stress how the growth of the Islamic State harms the stability of the Saudi state.

Efforts to go after online internet recruitment are harder given the ease of access to the internet, legitimate concerns about freedom of speech, and the ability of the Islamic State to re-create accounts that have been taken down. Stern and Berger argue convincingly, however, that taking down jihadist accounts has opportunity costs for the Islamic State: it must spend time to rebuild lost networks (Stern and Berger, p. 144). In addition, taking down accounts makes it harder for Islamic State recruiters to spam and otherwise broadcast widely.140


The Islamic State may be defeated or, more likely, diminished, but the broader movement it represents is unlikely to go away in the near future. Like al-Qaida before it, the Islamic State has tapped into a broader sentiment that enables recruitment and effective operations. The weakness—political as well as administrative—of regional governments, in particular, is likely to give radical movements such as the Islamic State room to flourish. As a result, instability in the Middle East is likely to continue, as is the terrorism threat to the West.



Director of National Intelligence Dennis C. Blair noted in 2009 the “continued decline of al-Qa'ida in Iraq and al-Qa'ida” (March) and remarked that “we've also got the rest of the world to worry about” (February). See Blair, “Annual Threat Assessment of the Intelligence Community for the Senate Armed Services Committee,” hearing before the Senate Armed Services Committee, 111th Cong., 1st sess., March 10, 2009, http://www.dni.gov/files/documents/Newsroom/Testimonies/20090310_testimony.pdf; and Blair, “Annual Threat Assessment,” hearing before the House Permanent Select Committee on Intelligence, 111th Cong., 1st sess., February 25, 2009, http://www.dni.gov/files/documents/Newsroom/Testimonies/20090225_transcript.pdf. In 2011, Clapper noted that al-Qaida in Iraq is not likely to be able to control territory. See James Clapper, “Worldwide Threat Assessment of the U.S. Intelligence Community,” statement before the Senate Select Committee on Intelligence, 112th Cong., 1st sess., February 16, 2011, http://www.dni.gov/files/documents/Newsroom/Testimonies/20110216_testimony_sfr.pdf.


Although many authors and policymakers use the terms “ISIS” or “ISIL”—acronyms for the Islamic State of Iraq in al-Sham (greater Syria or the Levant)—this label is both dated and misleading, and the group itself no longer uses it. The best term to use is “the Islamic State.” Stern and Berger note that they use “ISIS” for clarity but that “Islamic State” is the best term (p. 9). Similarly, Will McCants prefers the term “Islamic State” to the alternatives. See Shadi Hamid and McCants, “John Kerry Won't Call the Islamic State by Its Name Anymore. Why That's Not a Good Idea,” Washington Post, December 29, 2014, https://www.washingtonpost.com/posteverything/wp/2014/12/29/john-kerry-is-calling-the-islamic-state-by-the-wrong-name-and-its-helping-theislamic-state/.


Barack Obama, “Statement by the President” (Washington, D.C.: White House Office of the Press Secretary, August 7, 2014), https://www.whitehouse.gov/the-press-office/2014/08/07/statement-president.


Patrick Healy, “Republican Candidates Urge Aggressive Response after Paris Attacks,” New York Times, November 14, 2015, http://www.nytimes.com/2015/11/15/us/politics/republicancandidates-urge-aggressive-response-after-paris-attacks.html; and “Read Marco's Plan to Defeat ISIS” (Miami, Fla.: Marco Rubio for President, n.d.), https://marcorubio.com/issues-2/isis-planpolicy-proposal-defeat/.


Ginger Gibson, “After Paris, Americans Want U.S. to Do More to Attack Islamic State—Poll,” Reuters, November 16, 2015, http://www.reuters.com/article/us-france-shooting-usa-poll-idUSKCN0T528Y20151116; and Jonathan Martin and Dalia Sussman, “Fear of Terrorism Lifts Donald Trump in New York Times/CBS Poll,” New York Times, December 10, 2015, http://www.nytimes.com/2015/12/11/us/politics/fear-of-terrorism-lifts-donald-trump-in-new-york-timescbs-poll.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=firstcolumn-region&region=top-news&WT.nav=top-news&_r=0.


I am defining terrorism as political violence carried out by a nonstate group to achieve a psychological effect such as frightening or intimidating a government or a population.


The author has professional and personal ties to several of the authors of the books under review. In particular, J.M. Berger is a nonresident fellow at the Brookings Institution, where the author is a senior fellow, and William McCants is a senior fellow at Brookings and a friend of the author.


For a review of al-Qaida's early history, see R. Kim Cragin, “Early History of Al-Qa'ida,” Historical Journal, Vol. 51, No. 4 (December 2008), pp. 1047–1067.


“Zawahiri's Letter to Zarqawi” (West Point, N.Y.: Combating Terrorism Center at West Point, July 9, 2005), https://www.ctc.usma.edu/posts/zawahiris-letter-to-zarqawi-english-translation-2.


Joas Wagemakers, “Invoking Zarqawi: Abu Muhammad al-Maqdisi's Jihad Deficit,” West Point CTC Sentinel, June 15, 2009, https://www.ctc.usma.edu/posts/invoking-zarqawi-abumuhammad-al-maqdisi's-jihad-deficit.


Nir Rosen, In the Belly of the Green Bird: The Triumph of the Martyrs in Iraq (New York: Free Press, 2006), p. 142; Rajiv Chandrasekaran, Imperial Life in the Emerald City (New York: Alfred A. Knopf, 2006), p. 71; and Carter Malkasian, “The Role of Perceptions and Political Reform in Counterinsurgency: The Case of Western Iraq, 2004–2005,” Small Wars and Insurgencies, Vol. 17, No. 3 (September 2006), p. 372. For a broader review of counterinsurgency failures in Iraq, see Daniel Byman, “An Autopsy of the Iraq Debacle: Policy Failure or Bridge Too Far?” Security Studies, Vol. 17, No. 4 (October 2008), pp. 599–643.


Different groups had their own preferred way of killing and terrorizing their enemies. Sunni groups became known for beheadings, while some Shiite groups tortured their captives with electricity and drilled holes in their heads as a form of execution.


For an assessment of the so-called surge and other means of defeating AQI, see Stephen Biddle, Jeffrey A. Friedman, and Jacob N. Shapiro, “Testing the Surge: Why Did Violence Decline in Iraq in 2007?” International Security, Vol. 37, No. 1 (Summer 2012), pp. 7–40; John A. McCary, “The Anbar Awakening: An Alliance of Incentives,” Washington Quarterly, Vol. 32, No. 1 (January 2009), pp. 43–59, http://www.tandfonline.com/doi/pdf/10.1080/01636600802544905; and Stanley McChrystal, My Share of the Task: A Memoir (New York: Penguin, 2013).


“CIA Director Michael Hayden Says Al Qaeda Is on ‘Verge’ of Defeat in Iraq,” FoxNews.com, May 30, 2008, http://www.foxnews.com/story/2008/05/30/cia-director-michael-hayden-says-alqaeda-is-on-verge-defeat-in-iraq/. For a discussion of the criticism of al-Qaida, see Peter Bergen and Paul Cruickshank, “The Unraveling: Al-Qaeda's Revolt against Bin Ladin,” New Republic, June 11, 2008, https://newrepublic.com/article/64819/the-unraveling. Al-Qaida's core consists of the group's central leaders; it is based in Pakistan under Ayman al-Zawahiri's leadership.


Patrick Cockburn, The Jihadis Return: ISIS and the New Sunni Uprising (New York: OR, 2014), p. 32.


“Islamic State and Assad ‘Ignoring’ Each Other on the Battlefield, Says IHS Jane's Terrorism and Insurgency Centre” (Englewood, Colo.: IHS Jane's Terrorism and Insurgency Centre, December 12, 2014), http://press.ihs.com/press-release/aerospace-defense-terrorism/islamic-state-and-assad-ignoring-each-other-battlefield-sa.


Lina Khatib, “The Islamic State's Strategy: Lasting and Expanding” (Washington, D.C.: Carnegie Endowment for International Peace, June 2015), p. 4, http://carnegieendowment.org/files/islamic_state_strategy.pdf.


For a history of the Alawis, see Leon Goldsmith, Cycle of Fear: Syria's Alawites in War and Peace (London: Hurst, 2015).


Hassan Hassan, “Jihadis Grow More Dangerous as They Conquer Hearts in Syria,” National, March 6, 2013, http://www.thenational.ae/thenationalconversation/comment/jihadis-grow-more-dangerous-as-they-conquer-hearts-in-syria.


Ayman al-Zawahiri, “General Guidelines for Jihad,” As-Sahab Media, September 14, 2013.


Roula Khalaf, “The Deadly Contest between ISIS and al-Qaeda,” Financial Times, December 2, 2015, http://www.ft.com/intl/cms/s/2/297def12-9819-11e5-95c7-d47aa298f769.html-axzz3tflnulST.


“Sunni Rebels Declare a New ‘Islamic Caliphate,’” Al-Jazeera, June 30, 2014, http://www.aljazeera.com/news/middleeast/2014/06/isil-declares-new-islamic-caliphate-201462917326669749.html; and Raya Jalabi, “Who Are the Yazidis and Why Is ISIS Hunting Them?” Guardian, August 10, 2014, http://www.theguardian.com/world/2014/aug/07/who-yazidi-isis-iraq-religion-ethnicity-mountains.


As Bruce Hoffman argues, terrorists are, in their own minds, “altruists.” See Hoffman, Inside Terrorism (New York: Columbia University Press, 2013), p. 37.


Emman El-Badawy, Milo Comerford, and Peter Welby, “Inside the Jihadi Mind” (London: Centre on Religion and Geopolitics, Tony Blair Faith Foundation, October 2015), p. 4.


“The Return of the Khilafah,” Dabiq I, 2014, p. 11. Full text of Dabiq can be found at http://www.clarionproject.org/news/islamic-state-isis-isil-propaganda-magazine-dabiq.


F. Gregory Gause III, “Beyond Sectarianism: The New Middle East Cold War” (Washington, D.C.: Brookings Institution, July 22, 2014), http://www.brookings.edu/research/papers/2014/07/22-beyond-sectarianism-cold-war-gause; and Daniel Byman, “Sectarianism Afflicts the New Middle East,” Survival, February 1, 2014, http://www.iiss.org/en/publications/survival/sections/2014-4667/survival—global-politics-and-strategy-february-march-2014-e67d/56-1-08-byman-9f0f.


El-Badawy, Comerford, and Welby, “Inside the Jihadi Mind,” p. 4.


For a review of provocation and other strategies, see Andrew H. Kydd and Barbara F. Walter, “The Strategies of Terrorism,” International Security, Vol. 31, No. 1 (Summer 2006), pp. 49–80.


Murad Batal al-Shishani, “The Islamic State's Strategic and Tactical Plan for Iraq,” Terrorism Monitor, August 8, 2014, http://www.jamestown.org/programs/tm/single/?tx_ttnews%5Btt_news%5D=42728&cHash=25347708f9f9a0fc36db1096e5a68e13-.VmI1yuMrKHo.


Khatib, “The Islamic State's Strategy,” p. 14.


Mehdi Hassan, “What the Jihadists Who Bought ‘Islam For Dummies’ on Amazon Tell Us about Radicalisation,” Huffington Post, October 20, 2014, http://www.huffingtonpost.co.uk/mehdi-hasan/jihadist-radicalisation-islam-for-dummies_b_5697160.html.


Khatib, “The Islamic State's Strategy,” pp. 4–5.


The intellectual sources of the Islamic State's strategy are unclear. A number of scholars highlight Abu Bakr Naji's “The Management of Savagery” and Abu Musab al-Suri's work to show the strategic logic of many Islamic State actions. The Islamic State, however, is using at most part of these strategists' logic, and it is difficult to discern how much is derivative and how much is coincidence. See Will McCants, “How the Islamic State's Favorite Strategy Book Explains Recent Terrorist Attacks,” War on the Rocks blog, November 24, 2015, http://warontherocks.com/2015/11/how-the-islamic-states-favorite-strategy-book-explains-recent-terrorist-attacks/; Naji, “The Management of Savagery: The Most Critical Stage through Which the Umma Will Pass,” trans. Will McCants, provided by the John M. Olin Institute for Strategic Studies at Harvard University, May 23, 2006, https://azelin.files.wordpress.com/2010/08/abu-bakr-naji-the-management-of-savagery-the-most-critical-stage-through-which-the-umma-will-pass.pdf; and Suri, “The Global Islamic Resistance” [Da'wat al Muqawamah al-Islamiyyah al-Alamiyha, 2004], August 2, 2010, http://jihadology.net/category/individuals/strategists/abu-mu?ab-al-suri/.


Jeremy Shapiro et al., “ISIS and the Unbearable Stateness of Being” (Washington, D.C.: Brookings Institution, September 25, 2015), http://www.brookings.edu/blogs/order-from-chaos/posts/2015/09/25-isis-statehood-shapiro-mccants-indyk-hamid.


Charles Tilly, ed., The Formation of National States in Western Europe (Princeton, N.J.: Princeton University Press, 1975), p. 42.


Andrew F. March and Mara Revkin, “Caliphate of Law,” Foreign Affairs, April 15, 2015, https://www.foreignaffairs.com/articles/syria/2015-04-15/caliphate-law.


Khatib, “The Islamic State's Strategy,” p. 8.


Ibid., p. 7; and Kevin Sullivan, “Where the Poor Starve and the Tax Man Carriers a Whip,” Washington Post, October 1, 2015.


Khatib, “The Islamic State's Strategy,” p. 7.


For a review, see David S. Cohen, “Attacking ISIS's Financial Foundation,” remarks at the Carnegie Endowment for International Peace, October 23, 2014, http://www.treasury.gov/presscenter/press-releases/Pages/jl12672.aspx.


Khatib, “The Islamic State's Strategy,” p. 9.


Kevin Sullivan, “Spoils for the Rulers, Terror for the Ruled,” Washington Post, October 1, 2015.


Rukmini Callimachi, “ISIS Enshrines a Theology of Rape,” New York Times, August 13, 2015, http://www.nytimes.com/2015/08/14/world/middleeast/isis-enshrines-a-theology-of-rape.html?_r=0.


Kevin Sullivan, “‘Till Martyrdom Do Us Part,’” Washington Post, October 1, 2015.


Kevin Sullivan, “For Boys, God and Guns; For Girls, God and Cooking,” Washington Post, October 1, 2015.


Khatib, “The Islamic State's Strategy,” p. 7.


Sullivan, “Spoils for the Rulers, Terror for the Ruled.”


Sullivan, “‘Till Martyrdom Do Us Part.’”


See David D. Kirkpatrick, Ben Hubbard, and Eric Schmitt, “ISIS’ Grip on Libyan City Gives It a Fallback Option,” New York Times, November 29, 2015, http://www.nytimes.com/2015/11/29/world/middleeast/isis-grip-on-libyan-city-gives-it-a-fallback-option.html; and Daniel Byman, “ISIS Goes Global,” Foreign Affairs, Vol. 95, No. 2 (March/April 2016), pp. 76–85.


Charles Lister, “Competing Models of Global Jihad: Al-Qaeda and the Islamic State Vie for Preeminence” (Doha: Brookings Doha Center, forthcoming).


Daniel Byman, The Five Front War: The Better Way to Fight Global Jihad (Hoboken, N.J.: John Wiley and Sons, 2008), p. 24.


Sullivan, “Spoils for the Rulers, Terror for the Ruled.”


Sullivan, “Where the Poor Starve and the Tax Man Carriers a Whip.”


Kevin Sullivan, “A Climate of Fear and Violence,” Washington Post, October 1, 2015.


See Paul Collier and Anke Hoeffler, “Greed and Grievance in Civil War,” Oxford Economic Papers, Vol. 56, No. 4 (2004), pp. 563–595; and Paul Collier, “Rebellion as a Quasi-Criminal Activity,” Journal of Conflict Resolution, Vol. 44, No. 6 (December 2000), pp. 839–853.


Yuri Zhukov, “Counterinsurgency in a Non-Democratic State: The Russian Example,” in Paul B. Rich and Isabelle Duyvesteyn, eds., The Routledge Companion to Insurgency and Counter Insurgency (London: Routledge 2010), p. 13.


Stathis N. Kalyvas, The Logic of Violence in Civil Wars (New York: Cambridge University Press 2006), p. 158. See also Jason Lyall, “Does Indiscriminate Violence Incite Insurgent Attacks? Evidence from Chechnya,” Journal of Conflict Resolution, Vol. 53, No. 3 (June 2009), pp. 331–362.


Nathan Leites and Charles Wolf Jr., Rebellion and Authority: An Analytic Essay on Insurgent Conflict (Santa Monica, Calif.: RAND Corporation, 1970); and Charles Tilly, From Mobilization to Revolution (Indianapolis: Addison-Wesley, 1978), p. 100.


This paragraph is taken from Daniel Byman, “‘Death Solves All Problems’: The Authoritarian Model of Counterinsurgency,” Journal of Strategic Studies, Vol. 39, No. 1 (2016), pp. 62–93.


See Stephen M. Walt “ISIS as a Revolutionary State,” Foreign Affairs, Vol. 94, No. 6 (November/December 2015), https://www.foreignaffairs.com/articles/middle-east/isis-revolutionary-state.


Audrey Kurth Cronin, “ISIS Is Not a Terrorist Group,” Foreign Affairs, Vol. 94, No. 2 (March/April 2015), https://www.foreignaffairs.com/articles/middle-east/isis-not-terrorist-group.


Idean Salehyan, “Transnational Rebels: Neighboring States as Sanctuary for Rebel Groups,” World Politics, Vol. 59, No. 2 (January 2007), pp. 217–242; and Daniel Byman, Deadly Connections: States That Sponsor Terrorism (New York: Cambridge University Press, 2005).


See Naji, “The Management of Savagery,” p. 20.


McCants, “How the Islamic State's Favorite Strategy Book Explains Recent Terrorist Attacks.”


Virginia Page Fortna, “Do Terrorists Win? Rebels' Use of Terrorism and Civil War Outcomes,” International Organization, Vol. 69, No. 3 (Summer 2015), pp. 1–38.


Khatib, “The Islamic State's Strategy,” p. 12.


Seth G. Jones, “ISIS Will Become More Deadly before It Dies,” Slate, November 17, 2015, http://www.slate.com/articles/news_and_politics/foreigners/2015/11/isis_will_become_more_deadly_as_it_loses_territory.html.


Clint Watts, “What the Paris Attacks Taught Us about the Islamic State,” War on the Rocks blog, November 16, 2015, http://warontherocks.com/2015/11/what-paris-taught-us-about-the-islamicstate/.


Mao Tse-tung, On Guerrilla War (Champaign: University of Illinois, 2000), pp. 41–93.


Liz Sly, “The Hidden Hand behind the Islamic State Militants? Saddam Hussein's,” Washington Post, April 4, 2015, https://www.washingtonpost.com/world/middle_east/the-hidden-handbehind-the-islamic-state-militants-saddam-husseins/2015/04/04/aa97676c-cc32-11e4-8730-4f473416e759_story.html; and “Key Controversies and Missteps of the Postwar Period: De-Baathification,” PBS Frontline, n.d., http://www.pbs.org/wgbh/pages/frontline/yeariniraq/analysis/fuel.html.


Khatib, “The Islamic State's Strategy,” p. 18.


Alessandria Masi, “Jabhat Al-Nusra Leader Interview: ‘No Solution’ to ISIS, Al Qaeda Tension in Syria, Americans Joined Nusra Front” International Business Times, June 3, 2015, http://www.ibtimes.com/jabhat-al-nusra-leader-interview-no-solution-isis-al-qaeda-tension-syriaamericans-1951584; Mary Habeck, “Assessing the ISIS–al-Qaeda Split: Introduction” (New York: Soufan Group, August 2014), http://news.siteintelgroup.com/blog/index.php/about-us/21-jihad/4388-assessing-the-isis-al-qaeda-split-introduction; and Erika Solomon, “Fighters Flock Back to Resurgent al-Nusra,” Financial Times, March 30, 2015, http://www.ft.com/cms/s70/b0cc7652-d61b-11e4-b3e7-00144feab7de.html-axzz3tW8RPDcZ.


Soufan Group, “Foreign Fighters” (New York: Soufan Group, December 2015), p. 6, http://soufangroup.com/wp-content/uploads/2015/12/TSG_ForeignFightersUpdate1.pdf; and Nicholas J. Rasmussen, testimony, “Countering Violent Extremism: The Urgent Threat of Foreign Fighters and Homegrown Terror,” hearing before the House Committee on Homeland Security, 114th Cong., 1st sess., February 11, 2015, http://www.nctc.gov/docs/Countering_Violent_Islamist_Extremism.pdf.


See Mohammed M. Hafez, Suicide Bombers in Iraq: The Strategy and Ideology of Martyrdom (Washington, D.C.: United States Institute of Peace Press, 2007), pp. 251–254.


Edna Reid, “A Comparison of Jihadi Extremist Groups' Videos,” Forensic Science Communications, Vol. 11, No. 3 (July 2009), https://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/july2009/index.htm/research_tech/2009_07_research01.htm.


J.M. Berger, “Tailored Online Interventions: The Islamic State's Recruitment Strategy,” CTC Sentinel, October 23, 2015, https://www.ctc.usma.edu/posts/tailored-online-interventions-theislamic-states-recruitment-strategy.


Khatib, “The Islamic State's Strategy,” p. 13. The 3,000 figure comes from J.M. Berger and Heather Perez, “The Islamic State's Diminishing Returns on Twitter: How Suspensions Are Limiting the Social Networks of English-Speaking ISIS Supporters,” GW Program on Extremism, February 2016, https://cchs.gwu.edu/sites/cchs.gwu.edu/files/downloads/Berger_Occasional%20Paper.pdf


Thomas Hegghammer, “To Combat ISIS, Europe Must Do More to Police Social Media,” New York Times, November 19, 2015, http://www.nytimes.com/roomfordebate/2015/11/19/doeseurope-need-a-new-surveillance-system/to-combat-isis-europe-must-do-more-to-police-social-media.


Khatib, “The Islamic State's Strategy,” p. 11.


Sullivan, “Spoils for the Rulers, Terror for the Ruled.”


Kim Sengupta, “Turkey and Saudi Arabia Alarm the West by Backing Islamist Extremists the Americans Had Bombed in Syria,” Independent, May 13, 2015, http://www.independent.co.uk/news/world/middle-east/syria-crisis-turkey-and-saudi-arabia-shock-western-countries-bysupporting-anti-assad-jihadists-10242747.html; and “Syria Top Priority as Saudi Crown Prince Visits Turkey,” Al Arabiya, May 21, 2013, http://english.alarabiya.net/en/News/middle-east/2013/05/20/Syria-top-priority-as-Saudi-crown-prince-visits-Turkey.html.


Peter Van Buren, “Dude, Where's My Humvee? Iraq Losing Equipment to the Islamic State at Staggering Rate,” Reuters, June 2, 2015, http://blogs.reuters.com/great-debate/2015/06/02/dude-wheres-my-humvee-iraqi-equipment-losses-to-islamic-state-are-out-of-control/; and Andrew Tilghman and Jeff Schogol, “How Did 800 ISIS Fighters Rout 2 Iraqi Divisions?” Military Times, June 12, 2014, http://archive.militarytimes.com/article/20140612/NEWS08/306120062/How-did-800-ISIS-fighters-rout-2-Iraqi-divisions-.


“Special Report: Operation Inherent Resolve, Targeted Operations against ISIL Terrorists” (Washington, D.C.: U.S. Department of Defense, January 10, 2016), http://www.defense.gov/News/Special-Reports/0814_Inherent-Resolve; and Ashley Fantz, “War on ISIS: Who's Doing What?” CNN News, November 27, 2015, http://www.cnn.com/2015/11/20/world/war-on-isiswhos-doing-what/.


Mark Thompson, “Why More Airstrikes Won't Beat ISIS,” Time, November 17, 2015, http://time.com/4116888/paris-attacks-isis-strategy/. For a discussion of the limits of air power, see Robert A. Pape, Bombing to Win: Air Power and Coercion in War (Ithaca, N.Y.: Cornell University Press, 2014); and Daniel L. Byman and Matthew C. Waxman, “Kosovo and the Great Air Power Debate,” International Security, Vol. 24, No. 4 (Spring 2000), pp. 5–38.


David J. Kilcullen, “‘Twenty-Eight Articles’: Fundamentals of Company-Level Counterinsurgency,” Military Review, Vol. 86, No. 3 (March/April 2006), p. 103. For a formal statement of doctrine, see The U.S. Army/Marine Corps Counterinsurgency Field Manual, FM 3–24 (Chicago: University of Chicago Press, 2008).


Khatib, “The Islamic State's Strategy,” p. 10.


Jeremy M. Weinstein, Inside Rebellion: The Politics of Insurgent Violence (Cambridge: Cambridge University Press, 2007), pp. 198–259.


Charles Lister, “Yes, There Are 70,000 Moderate Opposition Fighters in Syria: Here's What We Know about Them,” Spectator, November 27, 2015, http://blogs.spectator.co.uk/2015/11/yesthere-are-70000-moderate-opposition-fighters-in-syria-heres-what-we-know-about-them/; Daniel R. DePetris, “Jabhat al-Nusra: Syria's Other Menace,” National Interest, November 30, 2015, http://nationalinterest.org/feature/jabhat-al-nusra-syrias-other-menace-14459; and Dexter Filkins, “The Limits of the Kurds' War on ISIS,” New Yorker, November 13, 2015, http://www.newyorker.com/news/news-desk/the-limits-of-the-kurds-war-on-isis.


Kathy Gilsinan, “Counting the ISIS Dead,” Atlantic, October 15, 2015, http://www.theatlantic.com/international/archive/2015/10/us-isis-fighters-killed/410599/.


Khatib, “The Islamic State's Strategy,” p. 22.


Sullivan, “Spoils for the Rulers, Terror for the Ruled.”


As quoted in ibid.


Jon Rosenthal, “European Jihadists Form ISIS Brigades in Syria,” Al Monitor, April 9, 2014, http://www.al-monitor.com/pulse/origmals/2014/04/europe-jihadist-isis-syria-qaeda-terror-france-germany.html#.


Khatib, “The Islamic State's Strategy,” p. 23.


For a review of the Islamic State's finances during this period, see Howard J. Shatz and Erin-Elizabeth Johnson, The Islamic State We Knew: Insights before Their Resurgence and Implications (Santa Monica, Calif.: RAND Corporation, 2015), pp. 8–9.


Matt Bradley and Mohammad Nour Alakraa, “Islamic State Scrambles to Stem Exodus of Skilled Workers,” Wall Street Journal, October 6, 2015, http://www.wsj.com/articles/islamic-statescrambles-to-stem-exodus-of-skilled-workers-1444174728.


“Reflections on the Final Crusade,” Dabiq IV: The Failed Crusade, October 11, 2014, https://media.clarionproject.org/files/islamic-state/islamic-state-isis-magazine-Issue-4-the-failedcrusade.pdf.


Khatib, “The Islamic State's Strategy,” p. 15.


Combating Terrorism Centre, The Osama Bin Laden Files: Letters and Documents Discovered by SEAL Team Six during Their Raid on Bin Laden's Compound (New York: Skyhorse, 2012), p. 161.


Thomas Hegghammer and Petter Nesser, “Assessing the Islamic State's Commitment to Attacking the West,” Perspectives on Terrorism, Vol. 9, No. 4 (August 2015), pp. 14–30.


Al-Shishani, “The Islamic State's Strategic and Tactical Plan for Iraq.”


Khatib, “The Islamic State's Strategy,” pp. 3, 15–16.


David Remnick, “Going the Distance,” New Yorker, January 27, 2014, http://www.newyorker.com/magazine/2014/01/07/going-the-distance-david-remnick.


Martin and Sussman, “Fear of Terrorism Lifts Donald Trump in New York Times/CBS Poll.”


Figures are from the Iraq Body Count database, December 8, 2015. See https://www.iraqbodycount.org/database/.


Russell Goldman and Karen Yaroush, “Where ISIS Claims to Have Struck, and Why,” New York Times, November 16, 2015, http://www.nytimes.com/2015/11/17/world/middleeast/where-isis-claims-it-has-struck-and-why.html.


International Crisis Group, “Lebanon's Self-Defeating Survival Strategies” (Brussels: International Crisis Group, July 20, 2015), http://www.crisisgroup.org/en/regions/middle-east-northafrica/syria-lebanon/lebanon/160-lebanon-s-self-defeating-survival-strategies.aspx.


Idean Salehyan and Kristian Skrede Gleditsch, “Refugees and the Spread of Civil War,” International Organization, Vol. 60, No. 2 (April 2006), pp. 335–366; and Daniel L. Byman and Kenneth M. Pollack, Things Fall Apart: Containing the Spillover from the Iraqi Civil War (Washington, D.C.: Brookings Institution Press, 2007).


On al-Qaida affiliates, see Barak Mendelsohn, The al-Qaeda Franchise: The Expansion of al-Qaeda and Its Consequences (Oxford: Oxford University Press, 2015); and Daniel Byman, “Buddies or Burdens? Understanding the Al Qaeda Relationship with Its Affiliate Organizations,” Security Studies, Vol. 23, No. 3 (2014), pp. 431–470.


Kirkpatrick, Hubbard, and Schmitt, “ISIS’ Grip on Libyan City Gives It a Fallback Option”; and Rukmini Callimachi, “In Newly Sophisticated Boko Haram Videos, Hints of Islamic State Ties,” New York Times, February 20, 2015, http://www.nytimes.com/2015/02/21/world/africa/innewly-sophisticated-boko-haram-videos-hints-of-islamic-state-ties.html.


Taimoor Shah and Joseph Goldstein, “Taliban Fighters in Afghanistan Are Seen as an Opening for ISIS,” New York Times, January 21, 2015, http://www.nytimes.com/2015/01/22/world/asia/taliban-fissures-in-afghanistan-are-seen-as-an-opemng-for-isis.html.


Sari Horowitz and Adam Goldman, “FBI Director: Number of Americans Traveling to Fight in Syria Increasing,” Washington Post, May 2, 2014, http://www.washingtonpost.com/world/national-security/fbi-director-number-of-americans-traveling-to-fight-in-syria-increasing/2014/05/02/6fa3d84e-d222-11e3-937f-d3026234b51c_story.html.


Jim Yardley et al., “Inquiry Finds Mounting Proof of Syria Links to Paris Attacks,” New York Times, November 15, 2015, http://www.nytimes.com/2015/11/16/world/europe/inquiry-finds-mounting-proof-of-syria-link-to-paris-attacks.html.


U.S. House of Representatives Homeland Security Committee, “ISIS Attack Plots against Western Targets” (Washington, D.C.: U.S. House of Representatives Homeland Security Committee, October 2015), https://homeland.house.gov/wp-content/uploads/2015/10/HHSC-October-Terror-Threat-Snapshot1.pdf. As of October 2015, there had been forty-one Islamic State–linked plots since January of that year, compared with twenty in 2014.


Hegghammer and Nesser, “Assessing the Islamic State's Commitment to Attacking the West.”


Daniel Byman and Jeremy Shapiro, “Be Afraid. Be a Little Afraid: The Threat of Terrorism from Western Foreign Fighters in Syria and Iraq” (Washington, D.C.: Brookings Institution, 2014), pp. 12–13, http://www.brookings.edu/~/media/research/files/papers/2014/11/western-foreign-fighters-in-syria-and-iraq-byman-shapiro/be-afraid—web.pdf.


“Deadly Attacks since 9/11” (Washington, D.C.: New American Foundation, n.d.), http://securitydata.newamerica.net/extremists/deadly-attacks.html.


Hegghammer and Nesser, “Assessing the Islamic State's Commitment to Attacking the West.”


Yardley et al., “Inquiry Finds Mounting Proof of Syria Links to Paris Attacks.”


Daniel Byman, “The Jihadist Returnee Threat: Just How Dangerous?” Political Science Quarterly, forthcoming.


Yara Bayoumy, “ISIS Urges More Attacks on Western ‘Disbelievers,’” Independent, September 22, 2014, http://www.independent.co.uk/news/world/middle-east/isis-urges-more-attacks-on-western-disbelievers-9749512.html.


For data on and an overview of the problem in the United States, including assessment of individuals motivated but not directed by the Islamic State, see Lorenzo Vidino and Seamus Hughes, “ISIS in America: From Retweets to Raqqa” (Washington, D.C.: George Washington University Program on Extremism, December 2015), https://cchs.gwu.edu/sites/cchs.gwu.edu/files/downloads/ISIS%20in%20America%20-%20Full%20Report.pdf.


On targeted killings, see Bryan C. Price, “Targeting Top Terrorists: How Leadership Decapitation Contributes to Counterterrorism,” International Security, Vol. 36, No. 4 (Spring 2012), pp. 9–46. For a critique, see Jenna Jordan, “Attacking the Leader, Missing the Mark: Why Terrorist Groups Survive Decapitation Strikes,” International Security, Vol. 38, No. 4 (Spring 2014), pp. 7–38. On intelligence cooperation, see Daniel Byman, “The Intelligence War on Terrorism,” Intelligence and National Security, Vol. 29, No. 6 (2014), pp. 837–863.


For arguments that the threat is overstated, see John Mueller and Mark G. Stewart. “The Terrorism Delusion: America's Overwrought Response to September 11,” International Security, Vol. 37, No. 1 (Summer 2012), pp. 81–110; as well as Risa A. Brooks, “Muslim ‘Homegrown’ Terrorism in the United States: How Serious Is the Threat?” International Security, Vol. 36, No. 2 (Fall 2011), pp. 7–47.


“Transcript of Obama's 2016 State of the Union,” New York Times, January 12, 2016, http://www.nytimes.com/2016/01/13/us/politics/obama-2016-sotu-transcript.html?_r=0; and “President Obama Provides Update on Our Strategy to Degrade and Destroy ISIL” (Washington, D.C.: White House, July 6, 2015), https://www.whitehouse.gov/blog/2015/07/06/president-obamaprovides-update-our-strategy-degrade-and-destroy-isil.


“The Expanding Web of Connections among the Paris Attackers,” New York Times, December 9, 2015, http://www.nytimes.com/interactive/2015/11/15/world/europe/manhunt-for-paris-attackers.html.


Loveday Morris, “Islamic State Is Losing Ground: Will That Mean More Attacks Overseas?” Washington Post, November 19, 2015, https://www.washingtonpost.com/world/the-islamic-stateis-losing-ground-will-that-mean-more-attacks-overseas/2015/11/18/14f18b10-8d8a-11e5-934ca369c80822c2_story.html; and U.S. Department of Defense, “Operation Inherent Resolve” (Washington, D.C.: U.S. Department of Defense, December 10, 2015), http://archive.defense.gov/home/features/2014/0814_iraq/.


For a discussion, see Shadi Hamid, “Is There a Method to ISIS's Madness?” Atlantic, November 23, 2015, http://www.theatlantic.com/international/archive/2015/11/isis-rational-actorparis-attacks/417312/.


Rukhmini Callimachi, “U.S. Seeks to Avoid Ground War Welcomed by Islamic State,” New York Times, December 8, 2015, http://www.nytimes.com/2015/12/08/world/middleeast/us-strategy-seeks-to-avoid-isis-prophecy.html.


Soufan Group, “Foreign Fighters.”


White House, Office of the Press Secretary, “Statement by NSC Spokesperson Ned Price on the Death of ISIL Deputy Leader Fadhil Ahmad al-Hayali” (Washington, D.C.: White House, Office of the Press Secretary, August 21, 2015), https://www.whitehouse.gov/the-press-office/2015/08/21/statement-nsc-spokesperson-ned-price-death-isil-deputy-leader-fadhil; and Lolita C. Baldor, “U.S. Airstrikes Kill 10 ISIS Leaders, Including Some Linked to Paris Attacks,” Associated Press, December 29, 2015, http://www.usnews.com/news/politics/articles/2015-12-29/us-official-10-islamic-state-leaders-killed-in-airstrikes.


Pape, Bombing to Win, pp. 314–331.


Khatib, “The Islamic State's Strategy,” p. 25.


For an argument on the importance of institutionalization, see Jordan, “Attacking the Leader, Missing the Mark.”


Byman, “The Intelligence War on Terrorism.”


Baldor, “U.S. Airstrikes Kill 10 ISIS Leaders, Including Some Linked to Paris Attacks.” For more on the difference between those who fight abroad and those who do not, see Thomas Hegghammer, “Should I Stay or Should I Go? Explaining Variation in Western Jihadists' Choice between Domestic and Foreign Fighting,” American Political Science Review, Vol. 107, No. 1 (February 2013), pp. 1–15.


Daniel L. Byman, “Friends Like These: Counterinsurgency and the War on Terrorism,” International Security, Vol. 31, No. 2 (Fall 2006), pp. 79–115.


Greg Miller and Scott Higham, “In a Propaganda War, U.S. Tried to Play by the Enemy's Rules,” Washington Post, May 8, 2015, https://www.washingtonpost.com/world/national-security/in-a-propaganda-war-us-tried-to-play-by-the-enemys-rules/2015/05/08/6eb6b732-e52f11e4-81ea-0649268f729e_story.html.


Berger, “Tailored Online Interventions.”