Violent Competition and Terrorist Restraint

A large literature has argued that domestic competition increases a militant organization's use and severity of terrorism to differentiate their “brand” and “outbid” other organizations. However, most empirical analyses infer such competition from the quantity of groups present in a geographic area. This approach neglects specific group relationships, such as cooperation, rhetorical or violent rivalry, or peaceful coexistence. We introduce a behavioral measure of group competition and argue that variation in the quality, rather than the quantity, of competition affects the violence profile of militant groups in unexpected ways. Violent competition, where militants attack one another, imposes significant constraints on group resources and increases groups’ dependence on civilian support, which exacerbates the costs of a popular backlash against brutality. Moreover, violent competition effectively substitutes for crowding out rivals via outbidding. As competition becomes extreme, we posit that groups increasingly opt for a strategy of terrorist restraint and reduce the share of high-profile attacks on soft civilian targets. We test this argument at the macro and micro levels with cross-national data on 290 organizations in civil war (1970–2018) and granular data on the subnational targeting strategy of the Islamic State in Syria (2013–2018). Both analyses provide robust support for our argument. The findings shed light on the strategic limitations of outbidding and provide important insights for research and policy.