International Migration and Military Intervention in Civil War

Which factors make it more likely that states militarily intervene in ongoing intrastate wars? We develop the argument that migrants, i.e., (1) people coming from the civil-war state living in a potential intervener state (immigrants) and (2) those living in the country at war who stem from the third party (emigrants), influence the decision of external states to intervene in civil wars. Our theoretical framework is thus based on a joint focus on domestic-level determinants in a civil-war country and in foreign states. Primarily based on an accountability rationale, we also claim that the third-party's regime type has an intervening influence. Using quantitative methods, our empirical results generally support the theory, although there is only weak evidence for the intervening influence of a third party's level of democracy.