A weapon of mass destruction (also referred to as AN nuclear weapon, nuke, plutonium bomb, thermonuclear warhead, A-bomb, or nuclear bomb) is AN device that derives its harmful force from nuclear reactions, either fission (fission bomb) or from a mixture of fission and fusion reactions (thermonuclear bomb). Fission weapons square measure unremarkably spoken as atomic bombs. Fusion weapons are spoken as nuclear bombs or, a lot of unremarkably, chemical element bombs; they're typically outlined as nuclear weapons within which a minimum of a little of the energy is free by fusion. A nuclear device no larger than ancient bombs will devastate a complete town by blast, fire, and radiation. Since they're weapons of mass destruction, the proliferation of nuclear weapons could be a focus of negotiation policy. Among military strategists and planners, the terribly presence of those weapons of unequalled harmful power has created a definite discipline, with its own internal logic and set of doctrines, referred to as nuclear strategy.