In this reconsideration of his controversial study Thinking about the Unthinkable (1962), Kahn addresses deterrence concepts and specific arms control issues which are likely to remain at the forefront of the nuclear debate. Taking into account the political, technical and moral developments of the past 20 years, he argues that since nuclear weapons exist and cannot be disinvented, it is crucial to maintain a militarily strong United States, while making every effort to enhance deterrence. He believes that for a government to pursue deterrence at any cost, without contingency plans, is not only irresponsible but immoral; and that the only justification for maintaining a nuclear arsenal is to deter, balance or correct the use of nuclear weapons by others. ISBN 0-671-47544-4 : $16.95.