Ethnic conflict has become one of the most prominent and bloody forms of violence in the world today. From the former Yugoslavia and Soviet Union to Africa, Asia, and Latin America, the competition among ethnic groups within state borders for control of resources and security has the capacity to destabilize regional international relations. This is especially so when other states choose to intervene in the domestic strife, whether due to humanitarian concerns or because of ethnic and strategic considerations. The essays in this volume examine when ethnic conflict is likely to lead to violence and especially when other states are likely to intervene. Throughout there is a focus on domestic institutions as the foundation to explain both when ethnic competition will escalate to violent conflict and when other states are prone to become involved, whether through providing external support to one or another ethnic or through direct intervention. The variety of approaches provide useful analytical tools for students, while the diversity of cases from different regions gives the reader a sense of the scope of such problems.