The Ideology That Binds Us: Homophily in Ideology and Terrorists Collaborations

Abstract

What brings different terrorist groups, organizations that are regularly secretive and competitive, to collaborate with one another? We build on scholarship that identifies ideology as a determining feature of terrorists’ behavior and draw on network studies that emphasize the role of homophily in creating collaboration. We suggest that the groups’ homophily in ideology plays a significant part in terrorists’ collaboration. Using network analysis, we examine collaborations across three case studies and different time frames: Pakistan, Colombia, and Italy. Our findings suggest that homophily in ideology is indeed a key predictor for collaboration yet that it also changed over time.

Disclosure statement

The authors declare there is no complete of interest at this study.

Notes

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2 Victor Asal and R. Karl Rethemeyer. “The Nature of the Beast: Organizational Structures and the Lethality of Terrorist Attacks,” The Journal of Politics 70, no. 2 (2008): 437–49. https://doi.org/10.1017/s0022381608080419.

3 See Appendix 1.

4 Martha Crenshaw, “The Causes of Terrorism,” Comparative Politics 13, no. 4 (1981): 379–99, https://doi.org/10.2307/421717; Ely Karmon, Coalitions Between Terrorist Organizations: Revolutionaries, Nationalists and Islamists (Leiden, Netherlands: Brill, 2005); Bruce Hoffman, Inside Terrorism (New York: Columbia University Press, 2017). Throughout the manuscript, when significant we use scholarship from parallel discussions on similar groups such as rebels, militias, and other violent nonstate actors to assure that we do not ignore important relevant contribution. We do not assert that all violent nonstate actors are similar to terrorists, yet we believe that those conversation can inform this work.

5 Victor H. Asal, Hyun Hee Park, R. Karl Rethemeyer, and Gary Ackerman, “With friends Like These… Why Terrorist Organizations Ally,” International Public Management Journal 19, no. 1 (2016): 1–30. https://doi.org/10.1080/10967494.2015.1027431;.Victor H. Asal, R. Karl Rethemeyer, and Eric W. Schoon, “Crime, Conflict, and the Legitimacy Trade-Off: Explaining Variation in Insurgents’ Participation in Crime,” The Journal of Politics 81, no. 2 (2019): 399–410. https://www.journals.uchicago.edu/doi/abs/10.1086/701492?journalCode=jop.

6 Mia Bloom, “Constructing Expertise: Terrorist Recruitment and “Talent Spotting” in the PIRA, Al Qaeda, and ISIS,” Studies in Conflict & Terrorism 40, no. 7 (2017): 603–23.; Laura Dugan, Gary LaFree, and Alex R. Piquero, “Testing a Rational Choice Model of Airline Hijackings,” Criminology 43, no. 4 (2005): 1031–65.; Kent Layne Oots, “Organizational Perspectives on the Formation and Disintegration of Terrorist Groups,” Studies in Conflict & Terrorism 12, no. 3 (1989): 139–52.

7 Karmon, Coalitions between Terrorist Organizations.

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27 Bapat and Bond, “Alliances between Militant Groups,” 793–824.

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30 Asal et al., “With Friends Like These,” 1–30.

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32 Karmon, Coalitions between Terrorist Organizations.

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39 Karmon, Coalitions between Terrorist Organizations.

40 Bacon, Why Terrorist Groups Form International Alliances.

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42 Fotini, Alliance Formation in Civil Wars.

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46 Asal et al., “With Friends Like These,” 1–30.

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48 Asal et al., “With Friends Like These,” 1–30.

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54 Karmon, Coalitions between Terrorist Organizations.

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56 Blair et al., “Honor among Thieves,” 164–203.

57 Asal et al., “With Friends Like These,” 1–30.

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59 Crenshaw, “The Causes of Terrorism,” 379–99.

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63 The MMN codebook acknowledges that it does not cover the entire universe of groups operating in each setting. We use the Global Terrorism Database to assess this gap and find that the MMN coverage is par with the GTD.

64 The other MMN’s maps focuses mostly on Jihadi groups.

65 Asal et al., “With Friends Like These,” 1–30; Asal et al., “Crime, Conflict, and the Legitimacy Trade-off,” 399–410.

66 Asal et al., “With Friends Like These,” 1–30.

67 See Appendix 1. Case study network maps.

68 A follow up analysis that explores the explanatory power of the first collaboration variable suggest that it is not a good indicator for the number of collaborations a group will have or its likelihood in following homophily-based collaborations.

69 Crenshaw, “The Causes of Terrorism,” 379–99; Rapoport, “The Four Waves of Modern Terrorism,” 3–11; Karmon, Coalitions between Terrorist Organizations.

70 Asal et al., “With Friends Like These,” 1–30; Milla et al., “Is the Role of Ideologists Central in Terrorist Networks?,” 333.

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73 Kilberg, “A Basic Model Explaining Terrorist Group Organizational Structure,” 810–30.

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78 Ackerman and Burnham, “Towards a Definition of Terrorist Ideology,” 1160–90; Holbrook and Horgan, “Terrorism and Ideology,” 2–15.

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83 Ackerman and Burnham, “Towards a Definition of Terrorist Ideology,” 1160–90.