What Do We Know about Civil War Outcomes?

Does political science research have something to add to the counterinsurgency strategy debate? Should the discipline even concern itself with debates over military doctrine and strategy? After conducting a thorough review of the extant empirical literature, we argue that the answer to both of these questions is yes. Evaluating the theoretical and empirical findings of the last two decades, we identify three dimensions of civil wars affecting who prevails: (i) state capacity, (ii) the effects of violence against civilians, and (iii) foreign intervention. Domestic armed conflicts are characterized not only by military struggles, but equally importantly by contests of legitimacy between incumbent and rebel visions for the state. We conclude that the analyses of COIN strategy cannot be divorced from assessments of state capacity and the role of external actors in the conflict. We thus see the academic literature as instrumental in adding to practitioners' perspectives by more clearly identifying what COIN strategies can be applied under state capacity and legitimacy constraints to facilitate peace through both population-centered (legitimacy) and insurgent-centered (battlefield effectiveness) strategies. Our analysis identifies points of consensus, but also highlights the gaps in our knowledge, which need attention from both academe and practitioners.