Foreign Fighters, Rebel Command Structure, and Civilian Targeting in Civil War

ABSTRACT

Recent studies find that the presence of foreign fighters in a rebel organization may increase levels of anti-civilian violence in civil war. But why? Evidence from some cases indicates that foreign fighters may be used intentionally by local rebel commanders to carry out abusive operations against noncombatants. Other cases, however, suggest that foreign fighters possess greater capacity for independent agency in war, stepping outside the chain of command to inflict harm against local noncombatants. We argue that variation in a rebel group’s command structure—specifically, their degree of centralization—offers a point of leverage with which to adjudicate between the generalizability of these competing explanations. We investigate this issue with an analysis of sixty-nine rebel groups active between 1989 and 2015. We find that the effect of foreign fighters on civilian targeting is conditional: foreign fighters are associated with greater levels of anti-civilian violence only when active in groups with centralized command structures. This study contributes to the nascent literature on foreign fighters, offering insight into how these actors step into the command structures of rebel organizations. This study also demonstrates that the abuse of civilians in conflict can be explained effectively based on the characteristics of armed parties.

KEYWORDS:

• Foreign fighters
• insurgency
• civilian targeting
• conflict violence

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Notes

1. Pauline Moore, “When do Ties Bind? Foreign Fighters, Social Embeddedness, and Violence Against Civilians,” Journal of Peace Research 56, no. 2 (2019): 279-94; Kristin Bakke, “Help Wanted? The Mixed Record of Foreign Fighters in Domestic Insurgencies,” International Security 38, no. 4 (2014): 150–87.

2. Scott Gates, “Recruitment and Allegiance the Microfoundations of Rebellion,” Journal of Conflict Resolution 46, no. 1 (2002):111–30; Lindsay Heger, Danielle Jung and Wendy H. Wong, “Organizing for Resistance: How Group Structure Impacts the Character of Violence,” Terrorism and Political Violence 24, no. 5 (2012): 743–68.

3. David Malet defines foreign fighters as “non-citizens of conflict states who join insurgencies during civil conflict” (2010: 12).

4. David Malet, “Why Foreign Fighters? Historical Perspectives and Solutions,” Orbis 54, no. 1 (2010): 97–114; Daniel Byman, “The Homecomings: What Happens when Arab Foreign Fighters in Iraq and Syria Return?” Studies in Conflict & Terrorism 38, no. 8 (2015): 581–602.

5. Bakke, “Help Wanted?” 150–87; Scott Gates and Sukanya Podder, “Social Media, Recruitment, Allegiance and the Islamic State,” Perspectives on Terrorism 9, no. 4 (2015):107–16.

6. Tiffany S. Chu and Alex Braithwaite, “The impact of Foreign Fighters on Civil Conflict Outcomes,” Research & Politics 4, no. 3 (2017): 1–7.

7. Malet, Foreign Fighters, 10.

8. Zachariah Mampilly, Rebel Rulers: Insurgent Governance and Civilian Life During War (Cornell, NY: Cornell University Press, 2012).

9. Benjamin Valentino, Paul Huth, and Dylan Balch-Lindsay, “‘Draining the Sea’: Mass Killing and Guerrilla Warfare,” International Organization 58, no. 2 (2004): 375-407.

10. Eli Berman and Aila M. Matanock, “The Empiricists’ Insurgency,” Annual Review of Political Science 18 (2015): 443-64; Jeremy Weinstein, Inside Rebellion: The Politics of Insurgent Violence (Cambridge, UK: Cambridge University Press, 2007).

11. Stathis Kalyvas, The Logic of Violence in Civil War (Cambridge, UK: Cambridge University Press, 2006); Alexander B. Downes, “Desperate Times, Desperate Measures: The Causes of Civilian Victimization in War,” International Security 30, no. 4 (2006): 152–95.

12. Berman and Matanock, “The Empiricists’ Insurgency.”

13. Dara Kay Cohen, “Explaining Rape during Civil War: Cross-national Evidence (1980–2009),” American Political Science Review 107, no. 3 (2013): 461–77.

14. Hanne Fjelde and Lisa Hultman, “Weakening the Enemy: A Disaggregated Study of Violence Against Civilians in Africa,” Journal of Conflict Resolution 58, no. 7 (2014): 1230–57.

15. Reed M. Wood, “Opportunities to Kill or Incentives for Restraint? Rebel Capabilities, The Origins of Support, and Civilian Victimization in Civil War,” Conflict Management and Peace Science 31, no. 5 (2014): 461–80.

16. Roos Haer, Armed Group Structure and Violence in Civil Wars: The Organizational Dynamics of Civilian Killing (New York: Routledge, 2015); Amelia Hoover Green, “The Commander’s Dilemma: Creating and Controlling Armed Group Violence,” Journal of Peace Research Fifty three, no. 5 (2016): 619–32; Christopher K. Butler, Tali Gluch, and Neil J. Mitchell, “Security Forces and Sexual Violence: A Cross-national Analysis of a Principal-Agent Argument,” Journal of Peace Research 44, no. 6 (2007): 669–87.

17. Heger, Jung, and Wong, “Organizing for Resistance”; Weinstein, Inside Rebellion, 204; Macartan Humphreys and Jeremy M. Weinstein, “Handling and Manhandling Civilians in Civil War,” American Political Science Review 100, no. 3 (2006): 429–47.

18. Moore, “When do Ties Bind?” 6.

19. Bakke, “Help Wanted,” 176.

20. Jack Knight, Institutions and Social Conflict (Cambridge, UK: Cambridge University Press, 1992).

21. Mary Jo Hatch, Organization Theory: Modern, Symbolic and Postmodern Perspectives (New York: Oxford University Press, 2006).

22. Haer, Armed Group Structure and Violence in Civil Wars; Abdulkader H. Sinno, Organizations at War in Afghanistan and Beyond (Ithaca, NY: Cornell University Press, 2008); Seth Jones, Waging Insurgent Warfare: Lessons from the Vietcong to the Islamic State (New York: Oxford University Press, 2017).

23. Heger, Jung, and Wong, “Organizing for Resistance,” 747. Similarly, Jacob Shapiro concludes that a centralized command structure makes militant groups “more effective by supporting resource sharing, specialization, economies of scale, and reduced contracting costs.” See Shapiro, The Terrorist’s Dilemma.

24. Heger, Jung, and Wong, “Organizing for Resistance,” 747.

25. Conversely, when the Provisional Irish Republican Army (PIRA) had to resort to more decentralized forms of leadership, control over group members decreased. By becoming more decentralized, “the leadership paradoxically [had] less control over strategy and thus less power to prevent the civilian casualties that provoke public opprobrium and internal dissent” (Horgan and Taylor 1997: 23).

26. Jacob N. Shapiro, The Terrorist’s Dilemma: Managing Violent Covert Organizations (Princeton, NJ: Princeton University Press, 2013).

27. Heger, Jung, and Wong, “Organizing for Resistance,” 748.

28. Humphreys and Weinstein, “Handling and Manhandling Civilians,” 445.

29. Hoover Green, “The Commander’s Dilemma,” 216.

30. Humphreys and Weinstein, “Handling and Manhandling Civilians,” 429.

31. Gates and Podder, “Social Media, Recruitment, Allegiance and the Islamic State,” 4.

32. Even militant groups with highly sophisticated and organized recruitment operations, such as the Islamic State in Iraq and the Levant, face this challenge. As Scott Gates and Sukanya Podder (2015) point out: “Given the very nature of being a foreign fighter, IS will know less about these individuals than about local recruits” (110). Similarly, Vera Mironova, in a study on the recruitment and management patterns of militant groups in Iraq and Syria, argues that “Foreign fighters are also harder for the group to screen” (2019: 38).

33. Bakke, “Help Wanted?” 161.

34. Human Rights Watch, “Youth, Poverty, and Blood: The Lethal Legacy of West Africa’s Regional Warriors,” (2005): 34, www.hrw.org/report/2005/04/13/youth- poverty-and-blood/lethal-legacy-west- africas-regional-warriors.

35. Human Rights Watch, “Syria: Criminal Justice for Serious Crimes Under International Law” (Technical Report, (2013), https://www.hrw.org.

36. Idean Salehyan, David Siroky and Reed M. Wood, “External Rebel Sponsorship and Civilian Abuse: A principal-Agent Analysis of Wartime Atrocities,” International Organization 68, no. 3 (2014): 650.

37. Weinstein, Inside Rebellion, 174.

38. Beth Elise Whitaker, James Walsh, Justin Conrad, “Natural Resource Exploitation and Sexual Violence by Rebel Groups,” Journal of Politics (forthcoming): 5-6.

39. Virginia Page Fortna, Nicholas J. Lotito, and Michael A. Rubin, “Don’t Bite the Hand that Feeds: Rebel Funding Sources and the Use of Terrorism in Civil Wars,” International Studies Quarterly 62, no. 4 (2018): 785.

40. Bakke, “Help Wanted?” 185.

41. Reuters World News, “Insight: Syria Rebels see Future Fight with Foreign Radicals,” https://www.reuters.com/article/us-syria-crisis-insight/insight-syria-rebels-see-future-fight-with-foreign-radicals-idUSBRE8770BK20120808. In the process of joining the Kurdish People’s Protection Units (YGP) forces, another U.S.-based foreign fighter recalls bringing $10,000 in cash, body armor with steel plates, food items, twenty five pairs of clean socks and ten packets of baby wipes (New York Times, “Meet the American Vigilantes Who Are Fighting ISIS,” 2015).

42. Malet, “The Foreign Fighters Playbook.”

43. Hardly the product of a leader’s “shaky hand,” examples from conflicts in places like Bosnia suggest that foreign fighters can potentially provide convenient cover for leaders who rely on foreign fighter brigades as part of a “sleight of hand” aggressive military strategy to target, influence, exploit or punish civilian populations. As Colonel Amir Kubura put it, “[The Bosnian commanders] knew, or had reason to know, that the [foreign fighters] under their command had committed or were going to commit these acts. They did not take necessary and reasonable measures to prevent them or punish those who committed them” (BBC 2003).

44. Dara Kay Cohen and Ragnhild Nordås, “Do States Delegate Shameful Violence to Militias? Patterns of Sexual Violence in Recent Armed Conflicts,” Journal of Conflict Resolution 59, no. 5 (2015): 877–898.

45. Organizations are “collective actors with formal membership boundaries; official, specialized goals; and routinely internal processes of decision-making control, and allocation of resources that structure the interactions between members” (Knight 1992).

46. This modeling approach has two desirable properties. First, it allows us to accommodate the nature of our dependent variable, counts of one-sided civilian casualties. Second, unlike other event count models, the negative binomial specification directly models the presence of over-dispersion in the conditional mean of the dependent variable. If over-dispersed data are incorrectly treated as having a Poisson distribution, the standard errors of the main coefficients will be biased downwards. The theta parameters in Table 1 suggest that the data are over-dispersed.

47. Our three main variables of interest—one-sided violence, the presence of foreign fighters, and centralized command structures—all come from different data sources. Therefore, our final set of sixty-nine rebel groups is determined by the overlap between the UCDP One-Sided Violence Dataset (v14.1, Eck and Hultman 2007), the Foreign Fighters Dataset (Malet 2013), and the Non-State Actors Dataset (Cunningham, Gleditsch, and Salehyan 2013) between 1989 and 2011. The fair regional distribution of group cases—e.g. the sixty-nine groups are active across forty countries and in all five of the UCDP regions—gives us greater confidence that these groups represent the larger population of rebel group cases active during this time.

48. Kristine Eck and Lisa Hultman, “One-sided Violence Against Civilians in War: Insights from New Fatality Data,” Journal of Peace Research 44, no. 2 (2007): 233–46.

49. Marie Allansson, Erik Melander and Lotta Themner, “Organized violence, 1989–2016,” Journal of Peace Research 54, no. 4 (2017): 574–87. There are a number of mechanisms by which the one-sided violence data may be flawed. In general, civilian casualty counts are often highly politized and lost in the fog of war. Underreporting is systematic and false precision is an ever-present issue As a result, we acknowledge that our data on civilian victimization are likely to be imprecise, i.e. they are approximations of the true number of civilian casualties. As a robustness check, we create an ordinal measure from these casualty counts and re-estimate our main models. The main results of our study remain robust to this test and are presented in the appendix. We operate on the assumption that reporting is not biased toward groups with either centralized or decentralized structures.

50. Malet, Foreign Fighters.

51. William S. Cleveland, “LOWESS: A Program for Smoothing Scatterplots by Robust Locally Weighted Regression,” The American Statistician 35 (1981): 54.

52. David Cunningham, Kristian Gleditsch and Idean Salehyan, “Non-state Actors in Civil Wars: A New Dataset,” Conflict Management and Peace Science 30, no. 5 (2013), 516–31.

53. According to the codebook for the Non-State Actors (NSA) data, when coding this variable, coders looked for evidence that “rebels have a clear central command.” To our knowledge, the NSA centralized control variable is the only large-N cross-national measure available in our sampled time range. A time-varying cross-sectional measure of rebel command structure is not available. Because our hypotheses are mostly concerned with the static relationship between group structure, foreign fighters, and anti-civilian violence, the measure provided in the NSA data is reasonably well-suited to test our proposed hypotheses.

54. Readers may wonder about the risk of selection bias. That is, do foreign fighters seek rebel organizations which may be more likely to engage in civilian targeting? We discuss this possibility in the included appendix. Decentralized rebel groups, on average, inflict higher levels of civilian victimization. To the contrary of what we would expect if selection bias were influencing our model results; however, it is groups with centralized command structures and foreign recruits which inflict the highest levels of civilian targeting. Therefore, we are highly confident in our claim that selection bias is not influencing our results. In fact, we would expect bias along these lines to work against our main results, which remain statistically discernible.

55. Nelson Kasfir, “Rebel Governance – Constructing a field of inquiry: Definitions, Scope, Patterns, Order, and Causes” in Rebel Governance in Civil War, edited by Ana Arjona, Nelson Kasfir, and Zachariah Mampilly (Cambridge, UK: Cambridge University Press, 2015): 21-46.

56. Cunningham, Gleditsch and Salehyan, “Non-state Actors in Civil Wars,” 516–31.

57. Moore, “Ties That Bind?” 284.

58. Reed M. Wood, Jacob D. Kathman and Stephen E. Gent, “Armed Intervention and Civilian Victimization in Intrastate Conflicts,” Journal of Peace Research 49, no. 5 (2012): 653.

59. Nils Petter Gleditsch, Peter Wallensteen, Mikael Eriksson, Margareta Sollenberg, and Håvard Strand, “Armed Conflict 1946-2001: A New Dataset,” Journal of Peace Research 39, no. 5 (2002): 615–37.

60. In the appendix, we investigate the potential confounding effects of additional control variables, including the extortion of lootable resources, rebel group size, and ethno-linguistic diversity. Our results are robust to these tests.

61. Cindy D. Kam and Robert J. Franzese, Modeling and Interpreting Interactive Hypotheses in Regression Analysis (Cambridge, UK: Cambridge University Press, 2007), 32.

62. We use the nbreg and margins commands in STATA 16 to calculate the predicted counts shown in Figure 2 and Figure 3.

63. Kam and Franzese, Modeling and Interpreting Interactive Hypotheses in Regression Analysis, 25.

64. For example, see Austin C. Doctor, “A Motion of No Confidence: Leadership and Rebel Fragmentation,” Journal of Global Security Studies (2020): 1-19.

65. Wood, Kathman, and Gent, “Armed Intervention and Civilian Victimization in Intrastate Conflicts,”647-660.

66. Salehyan, Siroky, and Wood, “External Rebel Sponsorship and Civilian Abuse,” 633–61; Jessica A. Stanton, Violence and Restraint in Civil War: Civilian Targeting in the Shadow of International Law (Cambridge, UK: Cambridge University Press, 2016).

67. Reed M. Wood and Jacob D. Kathman, “Competing for the Crown: Inter-rebel Competition and Civilian Targeting in Civil War,” Political Research Quarterly 68, no. 1 (2015): 167–79.

68. Humphreys and Weinsten, “Handling and Manhandling Civilians,” 429.

Additional information

Notes on contributors

Austin C. Doctor

Austin C. Doctor is an assistant professor at Eastern Kentucky University. He received his PhD from the School of Public and International Affairs at the University of Georgia in 2019.

John D. Willingham

John D. Willingham received his PhD from the School of Public and International Affairs at the University of Georgia in 2017. The views expressed in this article are his own and do not necessarily represent the views of the United States Government.