A collection of essays generated by Harvard's Avoiding Nuclear War Project, which previously put out Living With Nuclear Weapons (1983) and Hawks, Doves, and Owls (produced by the editors of the current volume). For four decades, our world has survived on a wing and a reliance on nuclear deterrence, with US and Soviet arsenals numbering over 50,000 nuclear weapons. Nevertheless, the deterrence system entails the possibility of catastrophe: the impetus for these explorations of ten scenarios for lessening the nuclear threat in the near future. These visions of ""desirable worlds"" are roughly grouped into (1) reduced vulnerability of populations (abolition, increased accuracy, or defense dominance of weapons); (2) reduced reliance on nuclear weapons (""lengthening the fuse"" or nonprovocative defense); (3) political accommodation (mutual cooperation or Soviet transformation); (4) Soviet decline; and (5) a new world system (internationalism or a world federation). Each essayist takes one of these ten scenarios and analyzes it based on the structure of national power, the interaction of states, the nature of domestic politics, the form and distribution of nuclear weaponry, and the nature and effects of technological changes. None of the ten scenarios comes out as a panacea. Even a world government still leaves the problem of civil wars breaking out, with the attendant threat of the use of nuclear weaponry; even abolition does not wipe out the knowledge and memories of nuclear scientists, enabling the re-creation of destroyed weapons. But the importance of this exercise is the hope of finding the germ of an idea to relieve the world of the tensions of possible destruction. Thoughtful, sincere work. Pie in the sky? Maybe--but consider the alternative.