As no national interest would justify inflicting genocide on the victim and suicide on the aggressor, a prevalent misconception is that nuclear war will never be fought. But the realities of our age compel an opposite assessment. In no previous epoch were adversaries so continuously and totally mobilized for instant war. It is a statistical certainly that hair-trigger readiness cannot endure as a permanent condition. Furthermore, the unrelenting growth in nuclear arsenals, the increasing accuracy of missiles, and the continuing computerization of response systems all promote instabilities which court nuclear war by technical malfunction; by miscalculation, human aberration or criminal act.