Contagion or Confusion? Why Conflicts Cluster in Space

TLDR

Civil wars cluster in space as well as time. The study develops and evaluates alternative explanations for spatial clustering of civil wars, examining whether it arises from country attributes or represents a threat to neighboring states and whether contagion risk depends on exposure to proximate conflicts. The authors empirically test these explanations by analyzing spatial patterns of intrastate conflict and assessing the influence of country characteristics, exposure to nearby conflicts, and ethnic ties. Results reveal a genuine neighborhood effect of armed conflict beyond country characteristics, with contagion driven by transnational ethnic linkages—particularly in separatist conflicts—rather than by exposure level.

Abstract

Civil wars cluster in space as well as time. In this study, we develop and evaluate empirically alternative explanations for this observed clustering. We consider whether the spatial pattern of intrastate conflict simply stems from a similar distribution of relevant country attributes or whether conflicts indeed constitute a threat to other proximate states. Our results strongly suggest that there is a genuine neighborhood effect of armed conflict, over and beyond what individual country characteristics can account for. We then examine whether the risk of contagion depends on the degree of exposure to proximate conflicts. Contrary to common expectations, this appears not to be the case. Rather, we find that conflict is more likely when there are ethnic ties to groups in a neighboring conflict and that contagion is primarily a feature of separatist conflicts. This suggests that transnational ethnic linkages constitute a central mechanism of conflict contagion.