The recent growth of concern over the danger of nuclear war has been dramatic and impressive. It is also eminently realistic. Any sane and rational person who considers the scale and character of contemporary military power, the current vast expansion of the military arsenals of the superpowers, and the proliferation of armaments throughout the world would surely have to conclude that the likelihood of a global catastrophe is not small.

One might argue, in fact, that it is a miracle that the catastrophe has not yet occurred. According to a Brookings Institutions study by Barry M. Blechman and Stephen S. Kaplan, from November, 1946, to October, 1973, there were nineteen incidents in which U.S. strategic nuclear forces were involved (we do hot have the record since, nor the record for the USSR and other powers). That means, to put it plainly, that every U.S. president regarded the use of nuclear weapons as a live policy option. The examples are instructive.