The Antiballistic Missile (ABM) Treaty of 1972 limited the number of defensive antiballistic missile systems allowed to the US and USSR. Effective ABM systems had been sought since the Cold War, when the nuclear arms race raised the specter of complete destruction by unstoppable ballistic missiles. In the West, the treaty was seen as a deterrent to nuclear war, since neither side would be able to fully protect against nuclear attack. Why then did the US withdraw from the treaty in 2002? Discuss