External Intervention, Identity, and Civil War

Scholarship on civil wars has focused on domestic causes, but recent research suggests that such causes are actually contingent on systemic conditions. We demonstrate this interaction concerning polarization. We provide statistical evidence for the importance of external intervention in conflict escalation. We then construct models in which external intervention is the catalyst for civil war in combination with other factors, focusing on ethnic or social identitification. In our model, local actors with a foreign patron are emboldened and pursue their objectives violently. Without the specter of intervention, polarization is not often suffcient to induce war. The model qualifies important empirical results that have established a direct, linear relationship between polarization and civil war and shows how it is possible to have war without asymmetric information or credible commitment problems. We present case examples consistent with our theoretical claim. The model serves as a bridge between international relations and comparative political-economy approaches to internal armed conflict.