The title of this book is somewhat misleading. Busch starts with the debate between Kenneth Waltz and Scott Sagan on whether more nuclear powers will bring the benefits of stability or just increase the risk of the ultimate catastrophe. Busch is more in the pessimistic Sagan camp and develops his point through an extremely systematic analysis, based on a thorough review of material in the public domain, of the safety threats stemming from extant and potential nuclear arsenals. (Israel manages to escape scrutiny because of the secrecy of its program.) Busch examines the command-and-control systems that should prevent accidental or unauthorized use and the fissile material protection, control, and accounting that should prevent facilities from being sabotaged and material from getting into the wrong hands. This does not make for an encouraging or easy read. Busch's conclusions no doubt would have been even more pessimistic had he been able to include the devastating revelations about A. Q. Khan's supply network run out of Pakistan.