The madman theory is a political theory commonly associated with the foreign policy of U.S. President Richard Nixon and his administration, who tried to make the leaders of hostile Communist Bloc nations think Nixon was irrational and volatile so that they would avoid provoking the U.S. in fear of an unpredictable response.

The US foreign policy during the presidency of Richard Nixon (1969–1974) focused on reducing the dangers of the Cold War among the Soviet Union and China. President Richard Nixon's policy sought on détente with both nations, which were hostile to the U.S. and to each other in the wake of the Sino-Soviet split. He moved away from the traditional American policy of containment of communism, hoping each side would seek American favor. Nixon's 1972 visit to China ushered in a new era of U.S.-China relations and effectively removed China as a Cold War foe. The Nixon administration signed the Anti-Ballistic Missile Treaty with the Soviet Union and organized a conference that led to the signing of the Helsinki Accords after Nixon left office.