July 31st is the 20-year anniversary of signing of the Strategic Arms Reduction Treaty (START) between the United States and the Soviet Union. The treaty, also known as START I, marked the beginning of a treaty-based reduction of U.S. and Soviet (later Russian) strategic nuclear forces after the end of the Cold War.
START I required each country to limit its number of accountable strategic delivery vehicles (ballistic missiles and long-range bombers) to no more than 1,600 with no more than 6,000 accountable warheads. The treaty came with a unique on-site inspection regime where inspectors from the two countries would inspect each other’s declared force levels. Thousands of other warheads were not affected and the treaty did not require destruction of a single nuclear warhead. START I entered into effect on December 5th, 2001, and expired on December 4, 2009.
Twenty years after the signing of START I, the United States and Russia are still in the drawdown phase of their strategic nuclear forces: START II followed in 1993, limiting the force levels to 3,500 accountable warheads by 2007 with no multiple warheads on land-based missiles; START II was never ratified by the U.S. Senate but surpassed by the Moscow Treaty in 2002, limiting the number of operationally deployed strategic warheads to 2,200 by 2012; The Moscow Treaty was replaced by the New START treaty signed in 2010, which limits the number of accountable strategic warheads to 1,550 on 700 deployed ballistic missiles and long-range bombers by 2018. Like its predecessors, New START does not limit thousands of non-deployed and non-strategic nuclear warheads and does not require destruction of a single warhead.
The Obama administration has stated that the next treaty must also place limits on non-deployed and non-strategic nuclear warheads.
This publication was made possible by a grant from Carnegie Corporation of New York and Ploughshares Fund. The statements made and views expressed are solely the responsibility of the author.
Researchers have many questions about the modernization of Pakistan’s nuclear-capable aircraft and associated air-launched cruise missiles.
The SIPRI chapter describes the nuclear weapon modernization programs underway in each nuclear-armed state and provides estimates for how many nuclear warheads each country possesses.
FAS researchers Hans Kristensen and Matt Korda with the Nuclear Information Project write in the new SIPRI Yearbook 2024, released today.
The total number of U.S. nuclear warheads are now estimated to include 1,770 deployed warheads, 1,938 reserved for operational forces. An additional 1,336 retired warheads are awaiting dismantlement, for a total inventory of 5,044 warheads.