This chapter outlines the nature of the multilateral regime to the defense of which the France, Germany, and the United Kingdom (E3)/European Union (EU)+3 came in 2003 and 2006, respectively. It looks at the global nonproliferation treaty (NPT) regime and its obligations for each state party, before analyzing the particular role of the International Atomic Energy Agency (IAEA) and, by extension, the UN, where the Security Council is tasked with maintaining international peace and security. The Treaty on the Non-Proliferation of Nuclear Weapons, as the NPT is officially called IAEA, aims to achieve different things with regard to the inherent dual-use nature of nuclear technology. The IAEA is an independent international organization, which is related to the UN system via a special agreement. The E3 initiative of 2003 and the EU's sustained subsequent involvement in the multilateral negotiations have to be seen with regard to the validity of the global nonproliferation system.