This volume assesses the European Union (EU) as a 'Diplomatic Actor' in key foreign policy fields in the post-Lisbon era. It brings together leading scholars and practitioners in order to examine the main players, processes and outcomes of the EU's collective diplomatic engagement in the fields of security, human rights, trade and finance and environmental politics. In addition, the collection also analyses institutional developments and the EU's responses to major internal and external challenges in the context of international politics and global diplomacy. It provides the first comprehensive overview of the scope, nature and impact of the EU's growing role as a diplomatic actor and offers a comparative analysis of EU diplomacy in bilateral, multilateral and international fora. By taking stock of the successes and failures of EU diplomacy, this volume identifies the main internal and external conditions that shape the EU's influence in global affairs.