Who Joins and Who Fights? Explaining Tacit Coalition Behavior Among Civil War Actors

Abstract

Which armed organizations form coalitions despite the inherent difficulties of cooperation in civil wars? We introduce the concept of tacit coalitions, which pertains to strategic and informal coalition behavior between civil war actors to address this puzzle. Our theoretical model of coalition behavior focuses on the trade-off between reaping benefits from pooling resources, while at the same time worrying about the division of spoils in case the coalition is successful in winning the conflict. It provides novel insights to the way synergies within potential coalitions affect this trade-off. The empirical section finds considerable support for our theoretical argument that actors are more likely to engage in tacit coalition behavior if a) potential coalitions are power balanced, b) joint capability of potential coalitions is not too high, and c) when coalitions can unlock synergies.