Origins of U.S. Nuclear Strategy, 1945-1953 [PDF ebook] 

The United States took almost a decade after Hiroshima and Nagasaki to develop a coherent strategy of nuclear deterrence. This comprehensive study by two careful and well-informed historians provides the best explanation we have of why this process took so long; it also suggests the inherent difficulties of relying on nuclear weapons to provide security in the first place. Required reading for anyone interested in the early history of the nuclear era.