The European Union (EU) is a unique political experiment that challenges many of the prevailing assumptions about world politics. This new book, by one of the leading American scholars on the EU, examines its key role in global politics and how the continued success of European integration means that scholars must rethink international relations theory. Drawing on the author's rich array of theory and empirical research in this area, this book addresses many of the key issues facing the EU. Core subjects covered include: *Theories of European integration *Liberal international relations theory *Constructivism and the EU *Legitimacy in the EU *European integration and national policies *Human rights and international law *Transatlantic relations Andrew Moravcsik has made many seminal contributions to our understanding of the European Union. This is essential new reading for all students and scholars with an interest in the EU,international relations and theories of world politics.