This panel will address the challenges and opportunities of seeking to achieve very low numbers of nuclear weapons, ultimately leading to zero. Receiving special attention will be the political and verification issues that would need to be resolved to make possible such a highly denuclearized condition, and coping with the threat of rearmament. Managing alliance dynamics, the impact of missile and air defenses and anti-submarine warfare, how deterrence changes as numbers are reduced, when and how to bring other countries into the process, how to account for high-capability conventional weapons, maintaining strategic and crisis stability as numbers become dramatically lower, space- and cyber-dynamics in security planning, the potential impact of other weapons of mass destruction, and other complicating issues will be aired as well. Given the important role that alliances play, the panel will discuss how alliances could accommodate such major nuclear reductions and what changes in alliances would be needed in alliances, and international relations more generally. Deep reductions and Global Zero would have major implications for nuclear nonproliferation, and vice versa, which this panel will also address. The different phases of greater reductions will be described, as will the contours of what compromises and component agreements would need to be worked out to reach agreements in each phase, with particular attention paid to achieving the first stage of reductions after New START and the likely obstacles to doing so.