This book is not about the immorality of war, nuclear or otherwise, nor is it about the current politics of disarmament. Rather, it seeks to provide readers with information on which to formulate their personal opinions, and to indicate the ways in which psychological knowledge might be applied to thinking about nuclear war. The BPS invited Dr James Thompson, in consultation with other psychologists, to prepare a statement concentrating on the psychological assumptions behind current civil defence planning and the likely psychological state of those who survive the immediate effects of nuclear bombing; human fallibility and the risk of accidental nuclear explosion; and conflict and negotiations'. This book is the result and is intended as an objective review of knowledge and experience related to these issues.