Terrorist group rivalries and alliances have important consequences, but the sources of these relationships are debated. This article offers a side-by-side examination of correlates of terrorist rivalries and alliances. Global analyses of hundreds of terrorist groups find violent rivalry is associated with drug trafficking, state sponsorship, ethnic motivation, and operating in a civil conflict country. Alliances are associated with territorial control, intermediate membership size, and religious motivation. The idea that alliances are an indicator of weakness does not find much support. When relationships are disaggregated into theoretically relevant categories (inter-field and intra-field rivalries, and domestic and international alliances), further distinctions appear
