In The Limits of Safety, Scott D. Sagan uses organizational theory to explain why a nuclear arsenal can never be completely free of accidents. He also describes many instances in which accidents have already occurred with nuclear weapons or that have occurred during tense strategic stand-offs between nuclear-armed states. As Sagan points out, it has really been nothing more than luck that such accidents that have occurred have not resulted in a catastrophic disaster.

Sagan's basic premise is that as systems get more complex, they get more difficult for human beings to effectively manage. The United States' nuclear weapons arsenal is one of the most complex systems in the world. Because of its complexity there are many supposedly fail-safe measures that are built into the system to prevent an accident from occurring, which only makes the system even more complex. As complexity rises so does the possibility of unintended consequences occurring as parts of the system interact in ways that the designers simply could not foresee.

Furthermore, some research in organizational theory strongly indicates that even if it were possible to design a "fail-safe" system, the need to have humans interacting with that system means that you can never eradicate all accidents and errors from occurring. Sagan more than adequately points out what the consequences of these revelations are for the maintenance of such a large nuclear arsenal as the United States and Russia currently have. ( )