Nuclear close calls

A nuclear close call is an incident that might have led to at least one nuclear explosion, but did not. They can be split into intentional use and unintentional use close calls.

Intentional use close calls may occur during increased military tensions involving one or more nuclear states. They may be a threat made by the state, or an attack upon the state. They may also come from nuclear terrorism.

Unintentional use close calls may occur due to equipment failure. Common examples are strategic bombers accidentally dropping or crashing with nuclear bombs, or early warning systems mistaking phenomena such as weather events or non-nuclear rocket launches for an ICBM first strike and therefore recommending a second strike.

Though exact details on many nuclear close calls are hard to come by, the analysis of particular cases has highlighted the importance of a variety of factors in preventing accidents. At an international level, this includes the importance of context and outside mediation; at the national level, effectiveness in government communications, and involvement of key decision-makers; and, at the individual level, the decisive role of individuals in following intuition and prudent decision-making, often in violation of protocol.

A possible example of an accident that did result in a nuclear explosion is the 2019 Nyonoksa radiation accident in Russia.

Any nuclear exchange carries the possibility of rapid climate change, threatening global food production: nuclear famine.

Despite reduction of nuclear arms and lower tensions after the end of the Cold War, estimated nuclear warhead stockpiles total roughly 15,000 worldwide, with the United States and Russia holding 90% of the total.