This book provides a helpful and accessible stocktaking of the position reached in the long-running debates on the relationship between the development and detonation of the first nuclear weapons and the onset of the Cold War. It is particularly good on the less familiar Russian material, including Stalin's determination not to let the West have the satisfaction of superior strength. The authors argue that without the bomb, it might have been possible for the United States and the Soviet Union to pursue a cooperative relationship; their nuclear programs, and the associated features of spies being unmasked and futile negotiations on international control, created additional mistrust between the two powers. Unfortunately, the evidence for this in the book is less than compelling, especially from the Soviet side. More time spent on what was going in Germany and Poland from 1945 on would have demonstrated the implausibility of the book's thesis. And it is at least worth examining the orthodox proposition that, since conflict was always in the cards, the bomb helped prevent the Cold War from getting too hot.