Logistical factors have assumed an increasingly important role in studies of civil wars. In particular, political economists have recently proposed models of insurgency that depend on states’ capacity to project power in rugged terrain rather than on ethnic allegiances. Yet, a large gap remains between the observed macro-level patterns and the postulated rationalistic micro-level explanations. Aiming to reproduce similar, logistical macro-level patterns, this paper offers an alternative account that interprets insurgency as processes of nationalist mobilization leading to violence when the power balance favors the peripheral communities over the centers. To articulate such identity-based mechanisms, I rely on a computational model, whose cross-national output is analyzed with multivariate regressions. The computational findings suggest that the search for explanations of civil wars needs to go beyond purely rationalist conjectures.