Past and Present Group Exclusion and Conflict: Group Marginalization, Opportunity, and Islamic State Foreign Fighter Mobilization

Researchers and policymakers have increasingly recognized foreign fighter mobilization as a national security threat to foreign states and domestic populations. Yet, scholars remain divided on the motivations of foreign combatants, arguing that fighters may be motivated by grievances, opportunity, or material incentives. The motivations of foreign fighters may be especially complex, as they are engaging in a conflict outside of their state. I analyze how historical and present-day group exclusionary policies and opportunity shape mobilization. To do so, I leverage novel data consisting of individual fighter data of Islamic State volunteers fighting in Iraq and Syria. Consistent with my theoretical framework, I find that a higher rate of Islamic State fighters come from areas where Sunni Muslims were denied access to political power and have greater state capacity.