ABSTRACT
A key element of President Obama's vision was the convening of a Nuclear Security Summit (NSS) of world leaders to focus high-level attention on the urgent challenge of securing all nuclear-weapon-usable materials. This initiative stood on the shoulders of several decades of efforts to address the potential for terrorists or others to gain access to highly enriched uranium (HEU) or plutonium—the necessary ingredients of nuclear weapons. In addition to the national and collective pledges, a further notable accomplishment of the NSS process was that two key nuclear security treaties gained dozens of new adherents. The 2005 Amendment to the CPPNM saw a fivefold increase in ratifications between 2009 and 2016, finally reaching the 101 countries required for that amendment to enter into force. The central coordinating role for the IAEA is a large and challenging job, given the enormous number of official and informal structures that make up the global nuclear security architecture.
