This book aims to explain the specifics of the EU’s approach to Iran, taking into account both the complexity of European foreign policy, in particular within transatlantic relations, and Iran’s (aspired) place in the international order. It informs the reader about the special negotiation format that included a number of world powers as well as multilateral bodies such as the International Atomic Energy Agency (IAEA) and the UN Security Council. Furthermore, the book provides an outlook on European strategies after the 2015 nuclear deal and offers conclusions on the effectiveness of Europe’s multilateral approach to foreign policy. By looking at the EU’s diplomatic activities toward Iran over more than a decade, the book focuses on Europe’s role in international politics.