Book excerpt: This book investigates the relationship between states and transborder ethnic groups in Eastern Europe. It uses the case of Hungary, which has long-standing ties to the nearly three million ethnic Hungarians in neighboring countries, to address why and how kin-states take action on behalf of their ethnic diasporas, and the consequences of that engagement for regional relations and domestic politics. The book argues that it is not ethnic affiliation, but elite political competition within a newly liberalized post-communist party system, together with European Union integration, that both drives increased engagement with ethnic kin abroad, and constrains its most dangerous forms.