What is mutually assured destruction or (mad) and what was its significance during the cold war?

Mutually Assured Destruction (MAD) is a military doctrine that posits that if two opposing sides both possess the capability to destroy each other with nuclear weapons, neither will initiate a conflict, as it would lead to total annihilation for both. During the Cold War, MAD served as a deterrent against nuclear war between the United States and the Soviet Union, as both superpowers recognized that any first strike would result in devastating retaliation. This precarious balance helped maintain a tense peace, despite numerous crises, because the catastrophic consequences of nuclear conflict were understood by both sides. Ultimately, MAD shaped nuclear strategy and international relations during this period, influencing arms control negotiations and military planning.