TASS FACTBOX. On February 5, 2026, the Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms - the last remaining agreement regulating US-Russian strategic stability - expires. This marks the first time since the early 1970s, when the first US-Soviet disarmament treaties were signed, that the two nuclear-armed rivals will lack a comprehensive treaty to govern their arsenals. The TASS FACTBOX editorial team has taken an overview of the various nuclear arms agreements historically negotiated between the Soviet Union, Russia, and the United States.
The arms limitation negotiations between the Soviet Union and the United States began in 1969. These talks addressed strategic nuclear weapons, including land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), heavy bombers, as well as the corresponding launchers and the total number of nuclear warheads.
SALT I (1972-1977)
The interim agreement on certain measures relating to the Limitation of Strategic Offensive Arms (SALT I) was signed in Moscow on May 26, 1972. The document limited the number of ballistic missiles and launchers on land and submarines to the number in both countries' arsenals at the time. The number of warheads was not limited. The agreement was designed for five years, entering into force on October 3, 1972, and remained in effect until October 3, 1977.
ABM Treaty (1972-2002)
The Anti-Ballistic Missile Treaty (ABM Treaty) was signed in Moscow on May 26, 1972, simultaneously with SALT I, and entered into force on October 3, 1972. It enshrined the parties' commitment to renounce the development, testing, and deployment of sea-, air-, space-, and land-based missile defense systems or components, and permitted the deployment of missile defense systems on their territories only in two areas within a 150-kilometer radius. By pledging not to deploy missile defense systems along the perimeter of their borders, the Soviet Union and the United States created conditions under which neither side could deliver a first nuclear strike without fear of retaliation. This created a situation of equal vulnerability, or mutual nuclear deterrence. Under an additional protocol of July 3, 1974, the parties reduced the number of systems authorized for deployment from two to one. The Soviet Union retained this system around Moscow, while the United States maintained it around its ICBM deployment site at Grand Forks Air Base in North Dakota.
For 30 years, the ABM Treaty served as the foundation of strategic stability, underpinning SALT I and later strategic arms reduction agreements, as well as the Intermediate-Range Nuclear Forces Treaty. The ABM Treaty terminated on June 13, 2002, following the United States' withdrawal. Washington cited the need to protect US territory and its allies from North Korea and Iran, and subsequently deployed missile defense elements in Europe and South Korea. The US pullout upset parity of offensive and defensive capabilities.
SALT II (never took effect)
On June 18, 1979, the Strategic Arms Limitation Treaty (SALT II) was signed in Vienna. It established limits not only on ICBMs and SLBMs, but also on strategic bombers. Specifically, it proposed reducing the strategic nuclear delivery vehicles of each side initially to 2,400 pieces, and then to 2,250. Furthermore, the document set limits on the number of missiles equipped with multiple independently targetable re-entry vehicles (up to 1,320) and on the modernization of strategic systems. SALT II was intended to remain in force until the end of 1985, but it was not ratified by the United States and never entered into force.
INF Treaty (1987-2019)
On December 8, 1987, the Intermediate-Range Nuclear Forces Treaty (INF Treaty) was signed in Washington. It entered into force on June 1, 1988. The document eliminated an entire class of weapons - short-range (500-1,000 km) and medium-range (1,000-5,500 km) ballistic and cruise missiles capable of carrying nuclear warheads. The elimination of these missiles was completed in May 1991. In total, more than 2,500 missiles were destroyed on both sides. In 2014, the parties raised mutual grievances regarding the agreement's implementation. On August 2, 2019, the treaty was terminated at the initiative of the United States. Experts believe that by withdrawing from the INF Treaty, the United States removed its limitations in a potential confrontation with China (apart from China India, Pakistan, Israel, and North Korea currently possess nuclear-armed medium-range missiles).
START I (1991-2009)
The Treaty on the Reduction and Limitation of Strategic Offensive Arms (START I) was signed in Moscow on July 31, 1991, and entered into force on December 5, 1994. It provided for a reduction in nuclear arsenals by approximately 30% below deployed force levels. Within seven years, the parties committed to reducing the number of their nuclear warheads to 6,000 and nuclear delivery vehicles to 1,600. Furthermore, START I prohibited the development and modernization of certain nuclear delivery systems and the increase in the number of warheads on existing missiles. After the collapse of the Soviet Union Russia, Belarus, Kazakhstan, and Ukraine, on whose territories nuclear weapons were deployed, recognized themselves as successors to the treaty. By signing the Lisbon Protocol, an amendment to START I, on May 23, 1992, Belarus, Kazakhstan, and Ukraine transferred their nuclear weapons to Russia. On December 6, 2001, Russia and the United States declared their fulfillment of their obligations under START I. Its 15-year term expired on December 5, 2009.
START II (never took effect)
The Treaty on the Further Reduction and Limitation of Strategic Offensive Arms (START II), signed on January 3, 1993, was largely based on START I. START II envisioned a sharp reduction in the number of warheads on strategic delivery vehicles to 3,000-3,500 (two-thirds of the January 1993 level) and introduced a ban on the use of ballistic missiles with multiple reentry vehicles. The obligations were to be fulfilled by 2003, but the deadline was later pushed to the end of 2007. On September 26, 1997, Russia and the United States concluded the New York protocol to START II, which addressed the delineation of strategic and non-strategic missile defense systems. Russia subsequently ratified the agreement and the text of the treaty in April 2000. The United States had ratified START II back in 1996 (without linking it to the ABM Treaty), but the 1997 agreement was not submitted for ratification. On June 14, 2002, after the United States withdrew from the ABM Treaty, Russia announced the termination of its obligations under START II. No action was taken by the parties under this document, and it never entered into force.
SORT (2002-2011)
On May 24, 2002, the Strategic Offensive Reductions Treaty (SORT) between the United States and Russia was signed in Moscow. Under the treaty, the parties committed to limiting their strategic nuclear warheads to 1,700-2,200 pieces, approximately three times less than the limit established by START I. Russia and the United States were to achieve these limits by the end of 2012. The document did not stipulate a weapons elimination procedure - meaning that warheads removed from their launchers could be stored and subsequently retrieved - nor a verification mechanism. The transparency and irreversibility of the SORT reductions were largely ensured by the verification mechanism established by START I. The Strategic Offensive Reduction Treaty (START) entered into force on June 1, 2003. It was scheduled to run until December 31, 2012, but was cancelled early, on February 5, 2011, due to the entry into force of the New START Treaty. By this time, the United States, ahead of schedule, had reached the 2,200 warhead level.
New START (since 2010)
Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) was signed on April 8, 2010, in Prague and entered into force on February 5, 2011. It obliged Russia and the United States to reduce (and subsequently not exceed) the number of deployed strategic delivery vehicles on each side to 700 units within seven years, nuclear warheads on them to 1,550, and deployed and non-deployed launchers to 800. The United States reached the benchmarks in September 2017, and Russia on February 5, 2018. The document was designed for 10 years (until February 2021) with the possibility of a single extension for five years. Russia and the United States took advantage of this opportunity in 2021, extending it until February 5, 2026.
In February 2023, Russia suspended its participation in the treaty, but the parties continued to exchange notifications about strategic force exercises, ICBM and SLBM launches, and adhered to the treaty's quantitative limitations. In September 2025, Russia invited the United States to continue adhering to the agreement's limitations for another year, but received no response.