What happens when a region accustomed to violent shifts in borders is subjected to a new, peaceful partitioning? Has the European Union spent the last decade creating a new Iron Curtain at its fringes? Building Fortress Europe: The Polish-Ukrainian Frontier examines these questions from the perspective of the EU's new eastern external boundary. Since the Schengen Agreement in 1985, European states have worked together to create a territory free of internal borders and with heavily policed external boundaries. In 2004 those boundaries shifted east as the EU expanded to include eight postsocialist countries—including Poland but excluding neighboring Ukraine. Through an analysis of their shared frontier, Building Fortress Europe provides an ethnographic examination of the human, social, and political consequences of developing a specialized, targeted, and legally advanced border regime in the enlarged EU.