Terrorist Group Cooperation and Longevity


  • Brian J. Phillips is an assistant professor (profesor investigador títular) at the Centro de Investigación y Docencia Económicas (CIDE) in Mexico City. He researches organizational aspects of violence and consequences of conflict.”

  • Author's notes: Thanks to the following people for comments on earlier drafts and/or related discussions: Victor Asal, Allyson Benton, Ana Carolina Garriga, Chuck Gochman, Joy Langston, Phil Potter, Karl Rethemeyer, James Ron, Burcu Savun, Phil Williams, the anonymous reviewers, and presentation participants. Previous versions of the paper were presented at the 2011 annual meetings of the American Political Science Association, International Studies Association, Midwest Political Science Association, Political Networks Conference, and at CIDE. I thank Ian Anderson and Elsy González Cubría for help with data collection. All errors are mine. For replication data, see http://sites.google.com/site/brianjphillips/


Why do some terrorist groups survive considerably longer than others? The literature is just beginning to address this important question in a systematic manner. Additionally, and as with most studies of terrorism, longevity studies have ignored the possibility of interactions between terrorist groups. This article attempts to address these two gaps in the literature: the incomplete understanding of terrorist group survival and the tendency to assume that terrorist groups act independently. In spite of risks associated with cooperation, I argue that it should help involved terrorist groups mitigate mobilization concerns. More importantly, the impact of cooperation is conditioned by attributes of the country in which a terrorist group operates. Using new global data on terrorist groups between 1987 and 2005, I show that cooperation has the strongest effect on longevity in states where groups should have a harder time operating—more capable states and less democratic states. Interestingly, a group's number of relationships is more important than to whom the group is connected.