Anti-Ballistic Missile (ABM) Treaty

The Anti-Ballistic Missile (ABM) Treaty was signed on 26 May 1972 in Moscow by US President Richard Nixon and Soviet General Secretary Leonid Brezhnev, as a cornerstone of the first round of the Strategic Arms Limitation Talks (SALT I). Its strategic logic rested on the doctrine of Mutual Assured Destruction (MAD): if neither superpower could defend its territory against a retaliatory nuclear strike, neither would risk a first strike, and both would be discouraged from building costly offensive arsenals to overwhelm the other's defences. The Treaty was concluded for unlimited duration but allowed withdrawal on six months' notice if a party judged that "extraordinary events" jeopardised its supreme interests. It entered into force on 3 October 1972 after exchange of instruments of ratification.

Under its original terms, each party could deploy ABM systems at two designated sites — one protecting the national capital and one protecting an intercontinental ballistic missile (ICBM) field — with no more than 100 interceptor launchers and 100 interceptor missiles at each. A 1974 Protocol, signed 3 July 1974, reduced this to a single permitted site per party. The Soviet Union retained its Galosh system around Moscow, while the United States briefly operated the Safeguard system at Grand Forks, North Dakota, before deactivating it in 1976. The Treaty also prohibited the development, testing, or deployment of sea-based, air-based, space-based, or mobile land-based ABM systems, and barred transfer of ABM technology to third states — provisions later strained by disputes over the Soviet Krasnoyarsk radar and the US Strategic Defense Initiative ("Star Wars") announced by Ronald Reagan in 1983.

The Treaty's defining moment came on 13 December 2001, when President George W. Bush gave formal notice of US withdrawal, citing the need to develop missile defences against "rogue states" and terrorism after the September 11 attacks; the withdrawal took effect on 13 June 2002, making the United States the first party to abrogate a major arms-control treaty in the nuclear era. Russia, which had succeeded the USSR as the relevant party following the 1991 dissolution, declared the Treaty void in response and later pointed to US withdrawal as justification for developing hypersonic and novel delivery systems. By 2026 no successor ABM accord exists; strategic stability now rests narrowly on New START (2010, extended to 2026), whose own future is uncertain.

For the examinations, the ABM Treaty is tested in world-history and international-relations papers (UPSC GS-II and optional PSIR; FSOT US history and world affairs) as a pillar of Cold War détente alongside SALT I, the NPT (1968), and later INF Treaty (1987). Typical question angles ask candidates to explain the link between defensive limits and the MAD doctrine, to date and assess the 2002 US withdrawal and its consequences for arms control, and to compare the Treaty within the broader architecture of nuclear non-proliferation and disarmament regimes. Knowing the 1972 signatories, the 1974 single-site Protocol, and the 2001–2002 abrogation sequence is essential.