- the Anti-Ballistic Missile (ABM) Treaty, which limited strategic missile defenses to 200 (later 100) interceptors each, and
- the Interim Agreement Between the United States of America and the Union of Soviet Socialist Republics on Certain Measures with Respect to the Limitation of Strategic Offensive Arms (Interim Agreement or SALT I), an executive agreement that capped U.S. and Soviet intercontinental ballistic missiles (ICBM) and submarine-launched ballistic missile (SLBM) forces.
Under the Interim Agreement, both sides pledged not to construct new ICBM silos and not to increase the dimensions of existing ICBM silos “significantly,” and capped the number of SLBM launch tubes and SLBM-carrying submarines. The agreement ignored strategic bombers and did not address warhead numbers, leaving both sides free to enlarge their forces by deploying multiple independently targetable reentry vehicles (MIRVs) onto their ICBMs and SLBMs and increasing their bomber-based forces.
The agreement froze the number of launchers the United States and the Soviet Union could maintain, with Washington limited to its existing 1,054 ICBM silos and Moscow to its 1,618 silos. The agreement also capped the number of SLBM launch tubes for each side and allowed for an increase in launchers if done alongside the dismantling or destruction of a corresponding number of older ICBM or SLBM launchers. The United States was limited to 710 SLBM launch tubes, from its base level of 656 SLBM launch tubes, and no more than 44 modern ballistic missile submarines. The Soviet Union was limited to 950 SLBM launch tubes, from its base level of 740 SLBM launch tubes, and no more than 62 modern ballistic missile submarines.
In June 2002, the United States unilaterally withdrew from the ABM Treaty.
Official Text: https://2009-2017.state.gov/t/isn/4795.htm
More U.S.-Russian Nuclear Agreements: https://www.armscontrol.org/factsheets/USRussiaNuclearAgreements