"A nuclear war cannot be won and must never be fought." So Ronald Reagan and Mikhail Gorbachev affirmed, and so most people believe. The starting point of this masterful book by one of America's preeminent strategists, however, is that while the proposition is accepted, its deeper implications are not grasped. What the nuclear revolution has done is magnify in force and compress in time imperatives that were present in the pre-nuclear era; even then the pursuit of unlimited victory was unrealistic. The superpowers seem to have understood the implications of the revolution better in their actions, especially during crises, than in their declared policies. Jervis takes us through those implications in prose so lucid we feel we have known them all along.