Obama will need to begin discussions with the Russians, for example, on how to handle the question of short-range nuclear weapons, and how to regulate anti-ballistic missile defenses to maintain stability in a world of fewer offensive weapons. At some point, he must open discussions with countries like China, France, and Britain to understand better the conditions for transparency and verification that would be necessary for a clearer path toward eventual elimination of nuclear weapons in accordance with Article VI of the NPT.