A distinguished group of experts from thirteen countries explore how to overcome obstacles to nuclear disarmament and pose questions that require further official and nongovernmental deliberation. In the past few years, horizontal and vertical proliferation have collided. That is, the need for significant strengthening of the nonproliferation regime in the wake of nuclear developments in North Korea, Iran, Iraq, and Pakistan is now absolutely clear. So too, however, is growing unwillingness among non?nuclear-weapon states to even consider additional measures in what they see as the absence of serious progress by the nuclear-armed states toward disarmament. The pathbreaking paper Abolishing Nuclear Weapons by George Perkovich and James Acton was first published by the International Institute for Strategic Studies as an Adelphi Paper in September 2008. One of the paper?s major aims was to prompt serious international analysis, discussion, and debate, recognizing divergent views within and between nuclear-armed states and those that do not possess these weapons. The absence of such engagement in official forums such as Non-Proliferation Treaty Review Conferences and the Conference on Disarmament makes it vital for nongovernmental actors to take the lead in hopes that governments will see the value of such dialogue and follow...