The Anti-Ballistic Missile Treaty (ABM Treaty or ABMT) (1972–2002) was an arms control treaty between the United States and the Soviet Union on the limitation of the anti-ballistic missile (ABM) systems used in defending areas against ballistic missile-delivered nuclear weapons. It was intended to reduce pressures to build more nuclear weapons to maintain deterrence.
Under the terms of the treaty, each party was limited to two ABM complexes, each of which was to be limited to 100 anti-ballistic missiles.
Signed in 1972, it was in force for the next 30 years. In 1997, five years after the dissolution of the Soviet Union, four former Soviet republics agreed with the United States to succeed the USSR’s role in the treaty. Citing risks of nuclear blackmail, the United States withdrew from the treaty in June 2002, leading to its termination.
The United States first proposed an anti-ballistic missile treaty at the 1967 Glassboro Summit Conference during discussions between U.S. Secretary of Defense Robert McNamara and Chairman of the Council of Ministers of the Soviet Union Alexei Kosygin. McNamara argued both that ballistic missile defense could provoke an arms race, and that it might provoke a first-strike against the nation fielding the defense. Kosygin rejected this reasoning.
They were trying to minimize the number of nuclear missiles in the world. 4-5 Following the proposal of the Sentinel and Safeguard decisions on American ABM systems, the Strategic Arms Limitation Talks began in November 1969 (SALT I).
By 1972 an agreement had been reached to limit strategic defensive systems. Each country was allowed two sites at which it could base a defensive system, one for the capital and one for ICBM silos.
The treaty was signed during the 1972 Moscow Summit on 26 May by the President of the United States, Richard Nixon and the General Secretary of the Communist Party of the Soviet Union, Leonid Brezhnev; and ratified by the US Senate on 3 August 1972.
The 1974 Protocol reduced the number of sites to one per party, largely because neither country had developed a second site.
The sites were Moscow for the USSR and the North Dakota Safeguard Complex for the US, which was already under construction.