This volume examines the complex and vitally important ethical questions connected with the deployment of nuclear weapons and their use as a deterrent. A number of the essays contained here have already established themselves as penetrating and significant contributions to the debate on nuclear ethics. They have been revised to bring out their unity and coherence, and are integrated with new essays. The books exceptional rigor and clarity make it valuable whether the reader"s concern with nuclear ethics is professional or personal. Part I explores the morality of nuclear deterrrence from each of the two dominant traditions in moral philosophy, deontology and consequentialism, and points out a number of interesting ethical dilemmas. Part II criticizes a variety of alternatives to deterrence - unilateral nuclear disarmament, world government, strategic defense against ballistic missiles, and nuclear coercion - and argues for mutual nuclear disarmament as a realistic and desirable long-run alternative.