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Al Qaeda at the bar: coordinating ideologues and mercenaries in terrorist organizations


Most terrorist groups have limited lifespans. A number of scholars and casual observers have noted that terrorist organizations often are comprised of two types of participants: ideologues or “true believers” dedicated to the group’s cause, and mercenaries, who are adept at raising money through illegal means. The latter are interested primarily in their personal gains and have relatively little ideological commitment. Terrorist groups need both participants in order to function effectively. The purpose of the study is to understand the impact of communication on the compositions of terrorist groups. Three experimental treatments consider a coordination problem, and focus on the behavior of the mercenaries. Participants choose whether or not to participate in a terrorist attack. Payoffs are U-shaped in the number of participants, and increase with the number of successful attacks. The treatments allow communication between a leader and frontline fighters (“leader” treatment) or among the frontline fighters themselves (“communication” treatment). In the first treatment, a group leader can post messages to the members, which has a 19 % coordination success rate. For the communication treatment, all participants can post messages anonymously to each other, which yields a 27 % coordination success rate. By contrast, the baseline (“no communication” treatment) shows a success rate of 11 %. We conclude from our experimental evidence that disrupting communications among the frontline fighters is more effective in terminating terrorist organizations.

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  1. For instance, Colombia’s FARC was created as a Marxist revolutionary group, yet transformed into a drug trafficking cartel (Betancourt 2011). Several splinter groups of the IRA in Northern Ireland (the longest surviving terrorist organization) turned to criminal activities (English 2004). In addition, subgroups of the same movement can vary in their ideological commitments to a cause: the Maoist insurgents in India’s Andhra Pradesh state are highly ideologically motivated, while in the more lawless state of Bihar, terrorist groups are much more criminal in their orientation (Mukherjee and Yadav 1980; Singh 2006).

  2. In order to maintain secrecy, the ideologically motivated leaders must rely on the lower-level operatives, whose goals often diverge, to carry out tasks with minimal supervision, yielding a principal-agent problem. (Shapiro 2013, p. 250). Shapiro and Siegel (2007) similarly find that leaders delegate financial and logistical tasks to middlemen, but cannot monitor them perfectly for security reasons.

  3. Terrorist groups become inefficient because communication between members must be minimized to maintain secrecy.

  4. The experimental design uses a free-form communication technology as opposed to sending specific messages (which is a strategy used to control the content of communication). In a complex game such as the one we model, it is necessary to allow free form communication so as to capture the full range of strategies employed by the participants. We analyze the content of the messages in Sect. 5.

  5. Gupta (1990, 2008) argues that in analyzing collective action, individuals are motivated by concerns for the welfare of the group in addition to their own self-interest. This motivation, also known as “other regarding” preferences in behavioral economics (Bowles and Gintis 2011), is critical for understanding terrorist groups.

  6. The captive participants continue to be a part of the terrorist group because their costs from defection outweigh the benefits.

  7. Of course, terrorist groups can vary widely in their structures and their need for mercenaries in order to raise funds. The START database ( classifies terrorist groups both with and without benefactors. From this, we have identified the following 13 groups that are relevant for the type of terrorist group discussed in our model and experiment. These groups do not have a benefactor and recruit criminal mercenaries to finance their operations: examples include Abu Sayyaf Group, All Tripura Tiger Force, Armed Islamic Group, Communist Party of India (Maoist), Continuity Irish Republican Army, Basque (Euskadi ta Askatasuna), Loyalist Volunteer Force, National Democratic Front of Bodoland, People's Revolutionary Party of Kangleipak, Ulster Defense Association, Ulster Volunteer Force, Revolutionary Armed Forces of Colombia (FARC) and Shining Path (Carter 2012).

  8. Such conversion has been observed in terrorist groups such as the FARC (Cronin 2006) and the Abu Sayyaf (Rogers 2003).

  9. Cronin (2009, p. 148) points out that, “[c]riminal groups and terrorist groups often engage in similar behavior, including kidnappings, assassinations, and bombings, but their purposes are different.”

  10. Similarly, Hoffman (1998, p. 43) points out that, “the terrorist is fundamentally an altruist: he believes he is serving a’good’ cause designed to achieve a greater good for a wider constituency. The criminal, by comparison, serves no cause at all, just his own personal aggrandizement and material satiation.”

  11. The internal compositions of terrorist groups depend on many factors. Most begin as ideological groups; some are able to maintain their ideological orientations and sustain themselves over many years (such as the IRA, Hamas, or Hezbollah); some transform into criminal organizations, such as FARC or Abu Sayaaf (Cronin 2006); some, such as the Maoists in India, fracture along ideological lines (Gupta 2008, p. 175; Singh 2006), and most, such as the Japanese Red Army or the Baader Meinhof “gang”, eventually die out. Which path a terrorist group takes depends on its composition of the three types of actors (Dishman 2006; Gupta 1990, 2008).

  12. In reality, the activities of criminal groups and terrorist groups overlap considerably, making them hard to distinguish based on observed behavior alone. For example, the drug cartels in Mexico (criminal groups) and Al Qaeda in Afghanistan (a terrorist group) both engage in beheadings of their enemies. The Naxalites in India kidnap, Northern Ireland’s IRA robbed banks, Peru’s Shining Path was deeply involved in drug trafficking, and many terrorist groups engage in money laundering. Similarly, criminal groups engage in violent acts to terrorize organized society so that they can pursue their moneymaking operations without interference.

  13. The group becomes a criminal organization because fund-raising activities by the group (which necessarily are extra-legal) continue to pay for planning and logistics; however, the payoff from a successful attack never arrives, causing ideologues to abandon the cause, leaving mercenaries behind to continue the extra-legal fundraising activities.

  14. The third type, “captive participants”, is not considered in the experiments described below.

  15. In reality few human beings are pure altruists or pure self-utility maximizers. That is, most individuals have mixed motives (Andreoni 1989, 1990; Rose-Ackerman 1996; Hausken 1996). However, we impose strict behavioral assumptions for the sake of tractable analysis.

  16. See Sandler (2014) for a recent review of five areas of terrorism research that assume them to be rational actors.

  17. One critical assumption is that the ratio of mercenaries to ideologues is stable, whereas in practice it may fluctuate. The stability condition is used for simplicity, as the game is already rather complex.

  18. Communications can be disrupted by arresting operatives, monitoring and preventing face-to-face meetings, blocking or intercepting electronic (such as by phone, social media and email) and written messages, and letting members know that they are being watched closely.

  19. The extant literature acknowledges the fact that terrorist attacks vary in their scale. The 9/11 attacks were qualitatively different from kidnapping of ordinary US citizens by a terrorist organization in a conflict zone. We argue that the scale of an attack reflects a group’s relative ideological strengths. Ideologues aim to mix violence with theater for maximum political impact, while mercenaries prefer to work under the radar. A group’s choice of target speaks volumes about its commitment to the cause and contributes to terrorisms’ symbolic value (Berman and Laitin 2005; Atran 2002; Pape 2003). The choice of hard targets, which may include military bases and targets of national significance, would surely please the group’s political base (Bloom 2005) and confer a strategic advantage in acquiring a larger “market share” of that base (Gupta and Mundra 2005). Schmid and de Graaf (1982) argued that, in the final analysis, terrorism is a form of political communication.

  20. Hamas is an offshoot of the Muslim Brotherhood in Egypt, with an extensive history in the occupied territories. It is a strictly Sunni group. It developed an uneasy alliance with the Shiite, Iranian-supported group Hezbollah, but it relies mostly on contributions from the larger Palestinian community and from Sunni Arab countries in the Middle East. After Hamas formed a government in the Gaza strip in 2006, it has been able to raise money through taxes, fees, and fines similar to all other governments. It has also benefited from cross-border smuggling between Israel and Egypt (Mishal and Sela 2000; also see US State Department: ).

  21. Of course, the popularity enjoyed by Hamas is explained not just by suicide attacks. As Mannes et al. (2008) demonstrate (using a Stochastic Opponents Modeling Agents framework), a large component of Hamas’s popularity is attributable to the social services it provides, through which the group is able to recruit further suicide bombers. In addition, strategic alliances with other terrorist groups likewise allow Hamas to expand its operations because cooperation facilitates access to additional training, funding, and equipment (Mannes et al. 2008). In order to raise their profiles, terrorist groups need to carry out attacks on ever-larger scales to continue to attract both ideologues and mercenaries to the cause.

  22. Although it is assumed that a large-scale attack would increase the visibility, reputation, and power of an insurgent group, it could also draw harsh counterattacks from opposition groups. Furthermore, even successful attacks can backfire. For instance, in the 1990 s the IRA began what they called “proxy bombing,” whereby it would compel innocent victims to drive explosive-laden vehicles through British checkpoints and then blow them up using remote control devices. These acts were seen as evil by Northern Ireland’s Catholics and caused the IRA to lose significant public support (Maloney 2002).

  23. Our experiment focuses on the decisions of mercenaries, as they are motivated by economic incentives. The incentives of ideologues (by contrast) largely are ideological and difficult to combat as a matter of policy. That is, policies targeting ideologues engage in undermining terrorist ideology, which is outside the scope of this paper.

  24. Arthur (1994) assumes that each individual choosing to go once the bar has reached full capacity incurs the cost of travel but does not enjoy any benefits. We assume that all M = 10 participants wanting to visit the bar, i.e., participate in the terrorist attack, can do so and reap the benefits. However, if the attack includes any number of participants other than the optimal number, the attack is deemed unsuccessful, which has payoff implications in subsequent periods.

  25. History is quite clear on how success in carrying out spectacular attacks attract attention of like-minded ideologues from all over the world. The global spread of the Al Qaeda brand is closely tied to its successful attacks starting with the attack on the US embassies in East Africa in 1998, the USS Cole in Yemen in 2000, and finally, the 9/11 attacks (Rivers 2014; Wright 2007).

  26. Note that the mercenary’s payoff is not conditional on the success of an attack, though successful attacks do indeed increase overall payoffs by attracting more ideologues in future periods. We assume that all benefits from participation (including psychic benefits derived from simply participating) are modeled in the payoff function \(d_{1} \left( {\frac{{N_{i} }}{{N_{m} }}} \right) + d_{2} N_{m}\). If mercenaries captured additional payoffs conditional on the success of an attack, then the incentive to coordinate would be even more powerful for the mercenaries. This would encourage greater separation across the experimental treatments and make our results even stronger as the costs of mis-coordination would rise. Therefore, our results could be considered a conservative estimate.

  27. See Gupta (1990, 2008) for an expanded discussion of how mercenaries in terrorist groups earn the payoffs illustrated in Fig. 1.

  28. The shape of the payoff function will change if the payoffs for the mercenaries are unequal, such that the top leaders receive disproportionate shares of the spoils. In those circumstances, the crowding effects will be different based on an actor’s position within the organizational hierarchy. Analyzing unequal payoffs means analyzing organizational structure, which is left for future research.

  29. This begs the question: what determines the “scale” of attack? We posit that a large-scale attack should include the choice of target, extent of media coverage, number of casualties and, ultimately, the approval of the terrorist group’s political base.

  30. We keep this ideologue-mercenary ratio constant throughout the experiment. This ratio reflects the idea that larger terrorist groups engage in attacks on greater scales, requiring a larger number of mercenaries. Keeping this ratio constant simply means that smaller numbers of ideologues carry out smaller scale attacks, which require fewer mercenaries.

  31. An alternate method would be to adopt loaded terms, such as “terrorist attacks” and “terrorist groups”. However, using such loaded terminology with university students is certainly not appropriate in capturing the core decision problem faced by mercenaries. That is to say, no mercenary belonging to a terrorist organization would be deterred by the use of the word “terrorist.” However, it would be naïve to suggest that university students’ decisions would remain unbiased were loaded instructions to be used.

  32. However, the participants may adopt a wait-and-see approach, causing them to participate in the last two periods, if the target happens to be met during the first eight periods.


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We thank the National Science Foundation for financial support and participants at the conference “Bridging areas of expertise: funding research on terrorism,” October 7-10, 2010, for useful comments. We acknowledge support by NSF award BCS-0905044. We thank three referees of this journal and the editor for useful comments.

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Correspondence to Kjell Hausken.

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Hausken, K., Banuri, S., Gupta, D.K. et al. Al Qaeda at the bar: coordinating ideologues and mercenaries in terrorist organizations. Public Choice 164, 57–73 (2015).

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  • Terrorism
  • Terrorist organizations
  • Ideologues
  • Mercenaries
  • Laboratory experiment
  • Coordination

JEL Classification

  • C72
  • C91
  • C92
  • D71
  • H41