This edition examines the contexts in which the European Union has reflected and affected major forces and changes in international relations (IR) by drawing on concepts such as balance of power, multipolarity, multilateralism, interdependence, and globalization. It explores the nature of policymaking in the EU's international relations and the ways in which EU policies are pursued within the international arena. Topics include the EU's role in the global political economy, how the EU has developed an environmental policy, and how it has attempted to graft a common defence policy onto its generalized foreign and security policy. This chapter discusses the volume's methodological assumptions and considers three perspectives on IR and the EU: the EU as a subsystem of IR, the EU and the processes of IR, and the EU as a power in IR. It also provides an overview of the chapters that follow.