Many countries in Africa are embroiled in heated debates over who belongs where. Sometimes insider/outsider debates lead to localized skirmishes, but other times they turn into minor conflict or even war. How do we explain this variation in violence intensity? Deviating from traditional explanations regarding democratization, political or economic inequality, or natural resources, I examine how nationality laws shape patterns in violence.

Citizenship rules determine who is or is not a member of the national political community. Nationality laws formalize these rules, thus representing the legal bond between individuals and the state. Restrictive nationality laws increase marginalization, which fuels competition between citizenship regime winners and losers. This competition stokes contentious insider/outsider narratives that guide ethnic mobilization along the dual logics of threat and opportunity. Threats reduce resource levels and obstruct the exercise of rights. Opportunities provide the chance to reclaim lost resources or clarify nationality status.

Other work explains conditions necessary for insider/outsider violence to break out or escalate from the local to the national level. I show that this violence intensifies as laws become more exclusive and escalates to war once an outsider group with contested foreign origins faces denationalization. Groups have contested foreign origins where the “outsider” label conflates internal and foreign migrants. Where outsiders are primarily in-migrants, it is harder to deny the group’s right to citizenship, so nationality laws do not come under threat and insider/outsider violence remains constrained to minor conflict.

Using an original dataset of Africa’s nationality laws since 1989, I find that event frequency and fatality rates increase as laws become more restrictive. Through case studies, I explain when citizenship struggles should remain localized, or escalate to minor or major conflict. Next, I apply a nationality law lens to individual level conflict processes. With Afrobarometer survey data, I show that difficulty obtaining identity papers is positively correlated with the fear and use political violence. I also find that susceptibility to contentious narratives is positively associated with using violence to achieve political goals. Finally, I describe the lingering effects of a violent politics of belonging using original survey data from Côte d’Ivoire and Ghana.