The great library of Alexandria may have contained fewer volumes than the number which have been written on the subject of nuclear weapons in the Cold War. With the end of the Cold War, a new nuclear library is in the making. Much thought is being given to the next steps in nuclear policy, strategy, forces, arms control, and nonproliferation. For this very distinguished conference, however, I have been asked to look further ahead indeed, forward fifty-years. Prognostication is always a risky business. Detailed predictions beyond the shortest duration are difficult to label as ``scientific`` even in the social sciences. Forecasting ahead fifty years in an age of ever accelerating change would seem to be hopeless. Projecting the future of nuclear weapons, however, may not be as complex as one might think. Detailing the future fifty years from now is not necessary. We want to inform upcoming decisions by examining the possibilities, not write a history in advance of what is to happen. Our look forward con benefit from a brief look back fifty years. In retrospect, those years passed quickly, and with each additional year, analysts make them appear more simple than they seemed at the time. This paper …