Mutually Assured Destruction, or MAD, is a military strategy that emerged during the Cold War. It is based on the idea that if two opposing sides, such as the United States and the Soviet Union, both possess enough nuclear weapons to destroy each other, neither side would initiate a conflict. The fear of total annihilation acts as a deterrent against nuclear war. Under this doctrine, both sides maintain a second-strike capability, meaning they can respond to a nuclear attack with their own devastating retaliation. This balance of power aims to prevent any side from launching a first strike, as it would lead to catastrophic consequences for all involved.