Mutually Assured Destruction (MAD)
The notion of mutually assured destruction (MAD) refers to a national security policy whereby two opposing countries using weapons of mass destruction against each other would result in the irreversible annihilation of both parties. MAD is a component of the theory of deterrence, which holds that it is necessary for countries with nuclear weapons capabilities to threaten their deployment against a country threatening them with the same use of nuclear force in order to ensure that no attacks are carried out as such an attack would result in mutually assured destruction.