Part of the fascination of specialising in the law of the European Union (EU) is the sense of firing at a constantly moving target, and nowhere is this more obviously true than in the external relations field. European Union activity on the international scene is expanding rapidly, and there has been correspondingly rapid development of the legal concepts, principles and rules that are needed to organise it. Moreover, external relations law is bound to be affected by all that has been going on domestically within the EU. During the period of the conception, implementation and finalisation of the present volume, the EU has been involved in a gigantic enlargement operation; a Treaty establishing a Constitution for Europe (‘the Constitutional Treaty’) has been negotiated and signed, and then failed to secure ratification; and a debate has taken place, culminating in the signature on 13 December 2007 of a reforming Treaty, christened ‘Treaty of Lisbon’ (TL). This will incorporate most of the institutional and substantive reforms envisaged by the failed instrument, while eschewing its constitution-making pretensions.

There seemed to be a real need, therefore, for a volume taking stock of recent developments in the external relations law of the EC and in the law of the Common Foreign and Security Policy (CFSP) that results from Title V TEU, while also investigating the increasing interaction between these different fields of EU competence.