A nuclear weapon is a device or material that, when triggered, exploits the energy released by a nuclear reaction in order to produce an incredibly destructive explosion. Through the use of nuclear fission or fusion reactions, energy is released that is orders of magnitude greater than that of traditional chemical explosives. This energy can be used in a variety of forms, most notably through the detonation of a nuclear bomb. The indiscriminate risks and destruction of nuclear weapons has led to them becoming one of the most problematic elements of modern warfare and geopolitics.

See also: nuclear fuel, nuclear bomb, arms race, nuclear power