The U.S. National Academies (NAS) and the Russian Academy of Sciences (RAS), building on a foundation of years of interacademy cooperation, conducted a joint project to identify U.S. and Russian views on what the international nuclear security environment will be in 2015, what challenges may arise from that environment, and what options the U.S. and Russia have in partnering to address those challenges. The project's discussions were developed and expanded upon during a two-day public workshop held at the International Atomic Energy Agency in November 2007.