This report provides an analytical framework for thinking about the potential for militarized ethnic conflict in the central part of Europe and the Balkans. The report distinguishes between three types of ethnic tensions: (1) a mobilized ethnic group without outside backers, which can escalate to a low-intensity conflict within a specific country; (2) a mobilized ethnic group backed by a neighboring nation-state, which can escalate into an international dispute or border war; and (3) the breakup of federal states made up of ethno-territorial administrative units, which can escalate to armed struggle (a hybrid between a civil war and a war for independence that may escalate into a larger regional war). The report argues that the type of regional ethnic demands is shifting away from outright secession (breakup of states) and toward calls for autonomy. It concludes that U.S. policy should focus on controlling ethnic tensions by limiting their spread, preventing their escalation into militarized conflict, and containing any conflicts that occur. The report ends with some recommendations for the United States and the Army.