Background: In the 1980s, many medical organizations identified the prevention of nuclear war as one of the medical profession's most important goals. An assessment of the current danger is warranted given the radically changed context of the post–Cold War era.
Methods: We reviewed the recent literature on the status of nuclear arsenals and the risk of nuclear war. We then estimated the likely medical effects of a scenario identified by leading experts as posing a serious danger: an accidental launch of nuclear weapons. We assessed possible measures to reduce the risk of such an event.
Results: U.S. and Russian nuclear-weapons systems remain on high alert. This fact, combined with the aging of Russian technical systems, has recently increased the risk of an accidental nuclear attack. As a conservative estimate, an accidental intermediate-sized launch of weapons from a single Russian submarine would result in the deaths of 6,838,000 persons from firestorms in eight U.S. cities. Millions of other people would probably be exposed to potentially lethal radiation from fallout. An agreement to remove all nuclear missiles from high-level alert status and eliminate the capability of a rapid launch would put an end to this threat.
Conclusions: The risk of an accidental nuclear attack has increased in recent years, threatening a public health disaster of unprecedented scale. Physicians and medical organizations should work actively to help build support for the policy changes that would prevent such a disaster.