This book explains how state institutions affect ethnic mobilization. It focuses on how ethno-nationalist movements emerge on the political arena, develop organizational structures, frame demands, and attract followers. It does so in the context of examining the widespread surge of nationalist sentiment that occurred through the Soviet Union and Eastern Europe in the late 1980s and early 1990s. It shows that even during this period of institutional upheaval, pre-existing ethnic institutions affected the tactics of the movement leaders. It challenges the widely held perception that governing elites can kindle latent ethnic grievances virtually at will to maintain power. It argues that nationalist leaders can't always mobilize widespread popular support and that their success in doing so depends on the extent to which ethnicity is institutionalized by state structures. It shifts the study of ethnic mobilization from the whys of its emergence to the hows of its development as a political force.