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Correlates of Warning: Territory, Democracy, and Casualty Aversion in Terrorist Tactics

Published online by Cambridge University Press:  20 March 2020

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Terrorists attack civilian targets but there is variation in how many civilians they kill. Terrorists may deliberately harm civilians, or they may adopt a less bloody approach, demolishing businesses, transit systems, and other civilian property while employing tactics to avert civilian casualties. One such tactic is to warn civilians before an attack, allowing them to flee the area. With warnings as an example, this study considers why terrorists might adopt casualty-aversion tactics. An analysis of 12,235 bombings by 131 terrorist groups in the years 1970 to 2016 finds that warnings are most common when terrorists fight democracies and when they lack territorial strongholds. Ideological factors such as religion are not significant predictors of warnings. These findings suggest a need to revisit the claim that religion incentivizes indiscriminate terrorism. They also suggest a strategic logic behind casualty-aversion tactics. Terrorists fighting democracies may spare civilians to appear legitimate in citizens’ eyes. Terrorists without strongholds may spare civilians because they rely on the state's population for support. At first glance, my findings appear to contradict civil war literature arguing that militants with strongholds use violence more discriminately. However, terrorism occurs in areas of state control. Militants with strongholds can use indiscriminate terrorism against state-governed civilians without alienating their own supporters elsewhere.

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Copyright © The IO Foundation, 2020

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Abrahms, Max. 2007. Why Democracies Make Superior Counterterrorists. Security Studies 16 (2):223–53.CrossRefGoogle Scholar
Asal, Victor H., and Rethemeyer, R. Karl. 2008. The Nature of the Beast: Terrorist Organizational Characteristics and Organizational Lethality. Journal of Politics 70 (2):437–49.CrossRefGoogle Scholar
Asal, Victor H., and Rethemeyer, R. Karl. 2015. Big, Allied and Dangerous Dataset Version 2. Available at <>..>Google Scholar
Balcells, Laia. 2010. Rivalry and Revenge: Violence Against Civilians in Conventional Civil Wars. International Studies Quarterly 54 (2):291313.CrossRefGoogle Scholar
Beardsley, Kyle, Gleditsch, Kristian Skrede, and Lo, Nigel. 2015. Roving Bandits? The Geographic Evolution of Armed Conflicts. International Studies Quarterly 59 (3):503–16.CrossRefGoogle Scholar
Bloom, Mia M. 2005. Dying to Kill: the Allure of Suicide Terror. University of Pennsylvania Press.Google Scholar
Byman, Daniel L. 2011. The Lebanese Hizballah and Israeli Counterterrorism. Studies in Conflict and Terrorism 34 (12):917–41.CrossRefGoogle Scholar
Chenoweth, Erica. 2010. Democratic Competition and Terrorist Activity. Journal of Politics 72 (1):1630.CrossRefGoogle Scholar
Chenoweth, Erica. 2013. Terrorism and Democracy. Annual Review of Political Science 16:355–78.CrossRefGoogle Scholar
Choi, Seung-Whan. 2010. Fighting Terrorism Through the Rule of Law? Journal of Conflict Resolution 54 (6):940–66.CrossRefGoogle Scholar
Eck, Kristine, and Hultman, Lisa. 2007. One-Sided Violence Against Civilians in War: Insights from New Fatality Data. Journal of Peace Research 44 (2):233–46.CrossRefGoogle Scholar
Enders, Walter, and Sandler, Todd. 1991. Causality Between Transnational Terrorism and Tourism: The Case of Spain. Terrorism 14 (1):4958.CrossRefGoogle Scholar
Eubank, William Lee, and Weinberg, Leonard. 1994. Does Democracy Encourage Terrorism? Terrorism and Political Violence 6 (4):417–43.CrossRefGoogle Scholar
Fazal, Tanisha M. 2018. Wars of Law: Unintended Consequences in the Regulation of Armed Conflict. Cornell University Press.Google Scholar
Fortna, Virginia Page. 2015. Do Terrorists Win? Rebels’ Use of Terrorism and Civil War Outcomes. International Organization 69 (3):519–56.CrossRefGoogle Scholar
Gaibulloev, Khusrav, Piazza, James A., and Sandler, Todd. 2017. Regime Types and Terrorism. International Organization 71 (3):491522.CrossRefGoogle Scholar
Gelman, Andrew. 2006. Multilevel (Hierarchical) Modeling: What It Can and Cannot Do. Technometrics 48 (3):432–35.CrossRefGoogle Scholar
Gelman, Andrew, and Hill, Jennifer, eds. 2007. Data Analysis Using Regression and Multilevel/Hierarchical Models. Cambridge University Press.Google Scholar
Gibney, Mark, Cornett, Linda, Wood, Reed, and Haschke, Peter. 2015. Political Terror Scale 1976–2012. Available at <>..>Google Scholar
Goodwin, Jeff. 2006. A Theory of Categorical Terrorism. Social Forces 84 (4):2027–46.CrossRefGoogle Scholar
Harnden, Toby. 1999. Bandit Country. Hodder and Stoughton.Google Scholar
Hoffman, Bruce. 2006. Inside Terrorism. Columbia University Press.Google Scholar
Hoffman, Bruce, and McCormick, Gordon H.. 2004. Terrorism, Signaling, and Suicide Attack. Studies in Conflict and Terrorism 27 (4):243–81.CrossRefGoogle Scholar
Högbladh, Stina, Pettersson, Therése, and Themnér, Lotta. 2011. External Support in Armed Conflict 1975–2009: Presenting New Data. Paper presented at the International Studies Association convention, Montreal.Google Scholar
Horowitz, Michael C. 2010. Nonstate Actors and the Diffusion of Innovations: The Case of Suicide Terrorism. International Organization 64 (1):3364.CrossRefGoogle Scholar
Juergensmeyer, Mark. 2017. Terror in the Mind of God: The Global Rise of Religious Violence. University of California Press.Google Scholar
Kalyvas, Stathis. 2006. The Logic of Violence in Civil War. Cambridge University Press.CrossRefGoogle Scholar
Kalyvas, Stathis N., and Sánchez-Cuenca, Ignacio. 2005. Killing Without Dying: The Absence of Suicide Missions. In Making Sense of Suicide Missions, edited by Gambetta, Diego, 209–31. Oxford University Press.CrossRefGoogle Scholar
Kydd, Andrew H., and Walter, Barbara F.. 2006. The Strategies of Terrorism. International Security 31 (1):4980.CrossRefGoogle Scholar
Laqueur, Walter. 2000. The New Terrorism: Fanaticism and the Arms of Mass Destruction. Oxford University Press.Google Scholar
Mampilly, Zachariah Cherian. 2011. Rebel Rulers: Insurgent Governance and Civilian Life During War. Cornell University Press.Google Scholar
Mao, Zedong. 1989. On Guerrilla Warfare. United States Marine Corps (FMFRP 12-18).Google Scholar
Marshall, Monty G., Jaggers, Keith, and Gurr, Ted Robert. 2016. POLITY IV Project Dataset Users’ Manual. Vienna, Virginia: Center for Systemic Peace. Available at <>.Google Scholar
Merari, Ariel. 1993. Terrorism as a Strategy of Insurgency. Terrorism and Political Violence 5 (4):213–51.CrossRefGoogle Scholar
Moghadam, Assaf. 2008. Motives for Martyrdom: Al-Qaida, Salafi Jihad, and the Spread of Suicide Attacks. International Security 33 (3):4678.CrossRefGoogle Scholar
National Consortium for the Study of Terrorism and Responses to Terrorism (START). 2019. Global Terrorism Database [Data file]. Retrieved from <>..>Google Scholar
Niger Delta Avengers. 2016. Re: I Am Not Part of the Niger Delta Avengers Group—High Chief Government Ekpemupolo. Niger Delta Avengers, 3 May. [Blog post.] <>..>Google Scholar
Olson, Mancur. 1993. Dictatorship, Democracy, and Development. American Political Science Review 87 (3):567–76.CrossRefGoogle Scholar
Pape, Robert. 2005. Dying to Win: The Strategic Logic of Suicide Terrorism. Random House.Google Scholar
Piazza, James A., and Walsh, James I.. 2010. Why Respecting Physical Integrity Rights Reduces Terrorism. Comparative Political Studies 43 (5):551–77.Google Scholar
Rashid, Ahmed. 2000. Taliban: Militant Islam, Oil and Fundamentalism in Central Asia. Yale University Press.Google Scholar
Reinares, Fernando. 2012. Evidence of Al-Qa'ida's Role in the 2004 Madrid Attack. CTC Sentinel 5 (3):16.Google Scholar
Salehyan, Idean, Siroky, David, and Wood, Reed M.. 2014. External Rebel Sponsorship and Civilian Abuse: A Principal-Agent Analysis of Wartime Atrocities. International Organization 68 (3):633–61.CrossRefGoogle Scholar
Sánchez-Cuenca, Ignacio, and de la Calle, Luis. 2009. Domestic Terrorism: The Hidden Side of Political Violence. Annual Review of Political Science 12:3149.CrossRefGoogle Scholar
Schmid, Alex P. 2012. The Revised Academic Consensus Definition of Terrorism. Perspectives on Terrorism 6 (2):158–59.Google Scholar
Schmid, Alex P., and Jongman, Albert J.. 1988. Political Terrorism. Transaction Books.Google Scholar
Stanton, Jessica A. 2013. Terrorism in the Context of Civil War. Journal of Politics 75 (4):1009–22.CrossRefGoogle Scholar
Stern, Jessica. 2001. The Ultimate Terrorists. Harvard University Press.Google Scholar
Stewart, Megan A. 2018. Civil War as State-Making: Strategic Governance in Civil War. International Organization 72 (1):205–26.CrossRefGoogle Scholar
Stewart, Megan A., and Liou, Yu-Ming. 2017. Do Good Borders Make Good Rebels?: Territorial Control and Civilian Casualties. Journal of Politics 79 (1):284301.CrossRefGoogle Scholar
UNAMI/OHCHR. 2018. Unearthing Atrocities: Mass Graves in Territory Formerly Controlled by ISIL. United Nations Office of the High Commissioner for Human Rights. <>..>Google Scholar
Weinstein, Jeremy. 2006. Inside Rebellion: The Politics of Insurgent Violence. Cambridge University Press.CrossRefGoogle Scholar
Wood, Reed M. 2010. Rebel Capability and Strategic Violence Against Civilians. Journal of Peace Research 47 (5):601–14.CrossRefGoogle Scholar
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