Foreign Military Intervention and the Duration of Civil Wars Revisited

Abstract

Studies of the impact of foreign military intervention on the duration of civil wars most often fail to distinguish conflicts in which a single external state intervenes from those in which several outside states intervene. One influential quantitative analysis that does explore this distinction (Cunningham, Journal of Peace Research 47(2), 115–127, 2010) focuses primarily on whether or not the interests and preferences of the intervening state(s) coincide with those of prominent local actors. By revising this study’s dataset to clarify the distinction between single-state interventions and multiple-state interventions, it can be demonstrated that the latter are associated with lengthier wars than the former. Both types of foreign military interventions are correlated with civil wars that last longer than average.