Based on original research this book is an attempt at a general assessment of EU frontiers. Internal frontiers are losing some of their key functions but there are many responses to the new situation, as a case study of French frontiers abundantly illustrates. An examination of the EU external frontier shows that the EU is acquiring some state-like features, but the eastern frontier provides abundant evidence of the external frontier's complexity. The authors conclude that the increasing openness of national frontiers will continue, but their effective abolition, whether by European integration or through globalization, is improbable.