The prevailing assumptions about arms control, detente, and mutual deterrence are overwhelmingly positive. Yet detente and arms control have failed to achieve their objectives, and mutually assured destruction suffers from asymmetry because the Soviets plan for war in case deterrence fails. There is little evidence of the arms control dividend, which is a reduction of defense budgets and proliferation pressures. The arms control paradox is explained by basic assymetries: (1) the United States retrenches while the Soviets expand, (2) U.S. foreign policy evolves toward balance of power theories while the Soviets pursue a balance of terror doctrine, (3) the U.S. views arms control as an end in itself, while the Soviets consider it part of their global policy, and (4) the two countries have different historical experiences and perceptions of security.