Beyond Armed Competition: The Logic of Rebel Groups’ Alliance Formation

Why do rebel groups decide to create alliances with other non-state armed groups? And with whom? The existing literature on alliance formation in civil wars is divided into two paradigms. The former paradigm is related to a neo-realist approach to power politics drawing from the International Relations literature on alliance formation. In contrast, the latter considers the role of ethnic and ideological constituencies in determining rebel groups’ preferences. These two paradigms of alliance formation, although non-competitive, can answer the previous questions in combination. This article aims to reframe the existing scholarship on alliance formation in civil wars and bridge the two paradigms by developing a typology based on the role of the coalition’s short- and long-term goals and its internal composition in terms of ethnicity and ideology. The typology also presents a more nuanced understanding of why and with whom rebel groups ally by identifying four types of configurations, differentiating between tactical and strategic alliances, and homogeneous and heterogeneous compositions. By reframing the existing literature within the paradigms mentioned above and bridging them with the typology, the article paves the way for future research, particularly by understanding how alliances might change and evolve during civil wars.