Book excerpt: Expanding European Union activity on the international scene has led to development of the legal concepts, principles and rules that govern it. External relations law and practice have also been affected by events within the EU. This volume takes stock of the recent developments in the external relations law and practice of the EC/EU and investigates the increasing interaction between these different fields of Union competence. The first part of this book addresses issues that are broadly constitutional or institutional in character. The second part deals with various aspects of substantive external relations considered in a geographical or geopolitical perspective. The third part selects two specific substantive law areas - intellectual property law and environment law - as examples that illustrate the specific relationship between domestic policy and external relations.