Thinking about how terrorist groups end provides fresh strategic perspective on the fight against al-Qa`ida and its allies. It yields insight into the common patterns, tendencies, and vulnerabilities of terrorist campaigns, as there is much to learn from the history of how and why groups have failed. With an understanding of classic patterns, strategists can distinguish actions that move the process along from those that do not. Since the conflict is dynamic, envisioning the end offers a fresh mental framework both for the enemy’s actions and for the actions of the United States and its allies. Americans have painfully learned that states cannot win a war without winning the peace—or at least formulating a clear concept of what “peace” means. It follows that the best way to meet the current threat is to look beyond the international terrorist campaign inspired by al-Qa`ida, beyond the war in Afghanistan, to a broader vision of how this conflict will end.

A recent article in the CTC Sentinel by Leonard Weinberg and Arie Perliger, two well-respected terrorism experts, drew conclusions partly based on this author’s work on the endings of terrorist campaigns.[1] What follows clarifies and explains that research.[2] Good research into how terrorism ends avoids the temptation to argue that there is a single cause of failure for most groups. Terrorist campaigns are complex; there are no “silver bullets.” Two unfortunate tendencies emerge in interpreting research on how terrorist groups end: first, the myth of mutual exclusivity or uni-causality; and second, the belief that statistical frequencies provide a solid foundation for conclusions about specific threats. In a dynamic global context, there is no numerical substitute for judging which historical lessons are relevant and which are irrelevant to the end of al-Qa`ida. Failure to complete this hard analytical work can yield superficial conclusions that prolong the threat.

Overview: Six Pathways to the End

A better approach is to appreciate that terrorist groups end in complicated ways that apply to different kinds of groups under different conditions. There are at least six pathways to the decline and ending of terrorist groups in the modern era: decapitation, negotiations, success, failure, repression and reorientation.[3] These are not necessarily separate and distinct; for example, decapitation is often combined with implosion or repression. In the book How Terrorism Ends, for example, some groups—such as Chechen militants in Russia, the Irish Republican Army (IRA) in Britain, the Kurdistan Workers’ Party (PKK) in Turkey, among others—appear in more than one of the six chapters to emphasize that patterns can overlap. The book presents a thematic picture of the endings of groups, always arguing that individual groups may demonstrate more than one pattern. The following is a quick overview of these six pathways.

1. Decapitation

There are numerous examples where removing a group’s leader had a huge effect on the decline or ending of a group. Regardless of the leader’s operational role, removing a mouthpiece is a watershed. Sometimes leaders are arrested, as with Abimael Guzman and the Shining Path in Peru, or Shoko Asahara and Aum Shinrikyo in Japan. Sometimes they are killed, as were the leaders of the Abu Sayyaf Group in the Philippines (Abdurajak Abubakar Janjalani, Abu Sabaya and others), Chechen separatist leaders (Ibn Khattab, Abdul Khalim Saidullayev, Shamil Basayev and others), and Palestinians in Israel’s so-called “targeted killings.” The structure, size, age, and motivation of a group make a difference: those that have ended through decapitation have tended to be hierarchically structured, young, characterized by a cult of personality, and lacking a viable successor.[4] None of these describe al-Qa`ida.

2. Negotiations

Negotiations can lead to the achievement of some aims of a group and a decline or end of terrorism. Examples include the provisional IRA with the 1998 Good Friday Accords and the Palestinian Liberation Organization (PLO) with the 1990s peace process. Yet as these cases amply demonstrate, negotiations are not a panacea. Only a small percentage of groups (about 18%) have negotiated at all, and these tended to be long-lived groups: the average lifespan of groups that negotiate is between 20-25 years, whereas the average lifespan of terrorist groups overall tends to be about eight years.[5] More interesting still, of those that negotiate, only about 1 in 10 have the talks fail outright. On the other hand, few groups can be said to have achieved their aims.[6] The predominant pattern is for talks to move slowly, with a lower level of violence, without resolution or outright failure. Negotiations typically divert the violence to another channel and can be a necessary, if at times insufficient, ingredient leading to the end of a given campaign.

3. Success

Sometimes organizations fulfill their objectives. Yet if this pathway is to be meaningful at all, it is important to clarify “success”: most groups achieve tactical “process” goals that perpetuate the violence, but it is rare to achieve strategic “outcome” goals. Two classic cases of strategic success are Umkhonto, the military wing of the African National Congress (ANC), with the ending of apartheid; and Irgun Zvai Leumi (Irgun) with the establishment of the state of Israel. Gaining strategic objectives is rare: of the nearly 500 groups studied in How Terrorism Ends, only about 5% had by their own standards achieved their aims. To determine whether this statistic has any relevance to a specific threat, however, it is necessary to gain an in-depth understanding of the nature of the cause, its attractiveness, potential constituency, and the historical context within which it is being pursued. Not all causes or historical settings are equal.

4. Failure

There are two major ways that groups fail: they either implode by burning out or collapsing in upon themselves; or they lose popular support, making it difficult to operate or progress. Specific patterns include failure to pass the cause to the next generation, in-fighting and factionalization, loss of operational control, or accepting an exit or amnesty for individual members. Groups are marginalized when the ideology becomes irrelevant or the group loses contact with “the people”—usually as a result of police pressure. Yet one of the classic reasons for losing popular support is a group’s own mistakes and targeting errors resulting in a widespread popular backlash. Fear of this happening is deep in al-Qa`ida’s DNA: Ayman al-Zawahiri’s 2005 letter to Abu Mus`ab al-Zarqawi in Iraq directly echoes al-Zawahiri’s 1993 experience when his earlier group, Egyptian Islamic Jihad, met widespread popular revulsion and was gutted by the Egyptian government.[7] Al-Zawahiri understands that al-Qa`ida is deeply vulnerable to popular backlash due to its shaky theological legitimacy, sectarian targeting, brutal tactics, disruption of public order, and killing of innocent Muslims. Therefore, when analyzing al-Qa`ida, this is a pathway worthy of attention.

5. Repression

Repression—overwhelming military force abroad or police coercion at home—has resulted in the ending of a number of groups, including the People’s Will (Russia) and the Shining Path (Peru). States can certainly kill off a terrorist group if they are willing to destroy virtually everything. It is a common tack, especially for young governments. In fact, it is harder to think of states that have not used repression in response to terrorism than those that have.[8] Nevertheless, repression is a difficult ending to achieve. It can draw sympathy to a cause (Irish unity following Bloody Sunday), export the problem to another country or region (Ingushetia or Dagestan with the Chechens), or place severe strain upon the fabric of the state (democratic Uruguay’s response to the Tupamaros). It is also hard to sustain because of the high cost and because groups exploit strategies of leverage that turn a state’s strength against itself. An interesting historical dynamic is the tendency for states, especially democracies, to instinctively react with repressive measures but then gain sophistication as counterterrorism policy develops. While there have been gratifying operational gains and attacks averted, the limits of this approach are evident in terms of ending al-Qa`ida.

6. Reorientation

A final pathway is transition out of terrorism toward either criminal behavior and motivations (Abu Sayyaf, the Colombian FARC) or full insurgency or even conventional war, especially if supported by a state (the Algerian Armed Islamic Group, some Kashmiri separatist groups). The categories are blurred, however, as many groups use criminal activities to support terrorism, or terrorism to support criminal activities. When the political cause of a group is fully replaced by greed, the behaviors, structures, and support systems of groups likewise change—as do the methods needed to counter them. Some argue that al-Qa`ida has already transitioned to a global insurgency. If so, it is a bad outcome. Semantics matter: “insurgents” are honorable fighters, while “terrorists” are not. Arguing that core al-Qa`ida has command and control over local insurgencies throughout the world bestows legitimacy on it and places the United States and its allies into a pseudo-colonial role. It also deemphasizes the most vulnerable aspect of this movement: its targeting of innocent non-combatants, especially fellow Muslims.

Key Points to Remember about Research

Progress has been made in recent years in understanding how terrorist groups end. Yet one must be careful in drawing specific policy conclusions, especially extrapolating from unexplained statistical assertions about causality or regularity of endings. It is not meaningful to separate endings into categories of single frequency. Weinberg and Perliger, for example, stated that they had studied the endings of 232 individual groups, broken down into individual categories presented in a summary chart. The sum of all the numbers in the “Frequency” column of the chart was 232, the total number of groups that the authors defined as terrorism. The article explained, “With the exception of the latter [the success outcome], these causes are not mutually exclusive. One cause may, in reality, reinforce the other.”[9] Yet, in the chart each group is categorized as having had only one type of ending. This gives a misleading impression, especially for readers who concentrate their attention only on the chart.[10]

In the absence of more in-depth analysis or understanding, dubious conclusions might be reached on the basis of these numbers. In political science language, it is not clear how the 232 groups were “coded”—for example, what guided decisions about which groups to label with which ending. What is most striking is the remarkably high proportion of groups said to have ended with the capture or killing of group leadership (30.6%), even though decapitation is one of the endings commonly accompanied by other dynamics, especially implosion or repression. Moreover, there is no entry in the chart for “negotiations,” even though the article mentions that groups such as the Muslim Brotherhood and the IRA negotiated. In general, the chart highlights certain types of endings (especially decapitation and repression) while leaving out or downplaying others (negotiation, reorientation). In the absence of further analysis, policy prescriptions drawn up on the basis of such statistics risk being wrong, or even dangerous.


Instead of assessing the seriousness of the threat, the strength of al-Qai`da, or the success of the current fight against terrorism, different issues deserve focus, such as: What is known about how terrorist movements end? What has worked in previous counterterrorism campaigns? How close is the end of this threat? What will its characteristics be?

Research on how terrorism ends helps move closer to resolving these questions. There are no shortcuts. It is important to consider which of the lessons of how terrorism ends are relevant and which irrelevant to understand how, why, and under what circumstances al-Qa`ida will end—an assessment requiring an understanding of the political, cultural, and historical context, in-depth analysis of the enemy, a tolerance for complexity and a healthy appreciation for the limitations of statistics.

Dr. Audrey Kurth Cronin, Professor of Strategy and Director of War and Statecraft at the National War College, is the author of How Terrorism Ends: Understanding the Decline and Demise of Terrorist Campaigns (Princeton, NJ: Princeton University Press, 2009), “Ending Terrorism: Lessons for Defeating al-Qaeda,” Adelphi Paper No. 394, IISS (April 2008), “How al-Qaeda Ends,” International Security (2006), as well as numerous other books and publications. She is also Senior Research Associate and former Director of Studies for the Changing Character of War Programme at Oxford University. The views expressed in this article are strictly those of the author writing as an academic and do not represent official U.S. policy.

[1]  Leonard Weinberg and Arie Perliger, “How Terrorist Groups End,” CTC Sentinel 3:2 (2010).

[2]  See especially Audrey Kurth Cronin, How Terrorism Ends: Understanding the Decline and Demise of Terrorist Campaigns (Princeton, NJ:  Princeton University Press, 2009).

[3] These six pathways correspond to six chapters in Cronin, How Terrorism Ends, and are much more thoroughly explained in that body of work.

[4]  There is some excellent, recently-published work on this topic. See, for example, Jenna Jordan, “When Heads Roll: Assessing the Effectiveness of Leadership Decapitation,” Security Studies 18:4 (2009): pp. 719-755.

[5]  All of these statistics, including the list of groups included in the author’s study, the criteria for their inclusion, and the “coding” of their data is available either in the Appendix of How Terrorism Ends or at the website,

[6]  Again, for the specific derivation of this figure and its strengths and weaknesses, see the Appendix of How Terrorism Ends.

[7]  This is described well in Lawrence Wright, The Looming Tower (New York: Vintage Books, 2006).

[8]  A few examples of states that have used repression (especially early in a campaign) include: Argentina, Britain, China, Egypt, France, Germany, Mexico, Pakistan, Peru, the Philippines, Russia, Saudi Arabia, Turkey, and Uruguay.

[9]   Weinberg and Perliger.

[10] In the days following the article, for example, the author observed that this chart (Outcome/Frequency/Percentage) appeared on popular military blogs excised from the rest of the article.

Stay Informed

Sign up to receive updates from CTC.

Sign up