These were the first substantial arms control agreements between the two countries. Originally proposed by the United States in December 1966, the Soviet Union equivocated until May 1968, when the Soviets had numerical strategic parity in sight. A planned opening of SALT at a summit meeting in September 1968 was derailed by the Soviet‐led Warsaw Pact occupation of Czechoslovakia in August. With the defeat of the Democrats in the 1968 presidential election, SALT had to await a new administration and its review of defense and foreign policies. The delay of the opening of SALT from fall 1968 to late fall 1969 had one significant adverse effect: during that year, the United States successfully tested and developed deployable MIRV (multiple, independently targeted reentry vehicle) warheads for its strategic missiles—five years ahead of the Soviet Union. As a result, the negotiations placed no restrictions on these missiles and a significant continuing growth in numbers of warheads, seriously undercutting the value of the SALT I and SALT II agreements limiting strategic offensive delivery vehicles.
The two SALT I accords reached in May 1972 were the Anti‐Ballistic Missile (ABM) Treaty, which severely limited defenses against ballistic missiles (ABM defenses), and an Interim Agreement on the Limitation of Strategic Offensive Arms, which froze the total number of strategic offensive missile launchers pending further negotiation of a more comprehensive treaty limiting strategic missiles and bombers. (A separate agreement on measures to avert accidental use of nuclear weapons had been concluded in September 1971.) The ABM Treaty, of indefinite duration, restricted each party to two antiballistic missile sites, with 100 ABM launchers at each. In the only later amendment to the treaty, a 1974 protocol, the two parties agreed to forgo one of those sites, so that each was thereafter limited to a single deployment location. Further constraints included a ban on the testing and deployment of land‐mobile, sea‐based, air‐based, and space‐based systems. Only fixed, land‐based ABM systems could be deployed at the one allowed site. The Soviet Union kept its existing ABM deployment around Moscow. The United States completed its deployment at a site for defense of intercontinental ballistic missile (ICBM) launchers near Grand Forks, South Dakota, but in 1975 “mothballed” the complex as too expensive.
The ABM Treaty was a significant achievement in arms limitation, although agreement had been facilitated by doubts on both sides as to the cost‐effectiveness of available ABM systems. Although the treaty headed off a costly and useless ABM deployment race, it did not have the desired effect of also damping down deployment of strategic offensive missiles, especially because MIRVs were not constrained.
The Interim Agreement froze the level of land‐ and sea‐based strategic missiles (permitting completion of launchers already under construction). The Soviet Union had a quantitative advantage with 2,348 missile launchers to 1,710 for the United States. This was, however, offset in two important ways. First, neither strategic bombers nor forward‐based nuclear delivery systems were included, and the United States had a significant advantage in both categories. Second, although the Soviet Union had more missile launchers and deployed missiles, the United States had a larger number of strategic missile warheads and by 1972 had already begun deploying MIRV warheads. Overall, the Interim Agreement placed only modest limits on strategic missiles. In contrast to the ABM Treaty, it was not significant as an arms control measure.
President Gerald R. Ford and Soviet leader Leonid Brezhnev reached an agreement at Vladivostok in November 1974 to place a cap of 1,320 on the number of MIRV warheads and equal overall levels of strategic nuclear delivery vehicles at 2,400, including strategic bombers. This was not, however, a formal agreement and efforts to reach a SALT II Treaty to replace the SALT I Interim Agreement remained stalemated for another five years.
Another abortive attempt to conclude an early SALT II Treaty was made by President Jimmy Carter in March 1977, soon after assuming office. He attempted to set aside the Vladivostok accord and plunge into deeper cuts, but the attempt failed because it abandoned the earlier basis for agreement by seeking reductions of Soviet intercontinental systems not covered in the proposed treaty. The negotiations got back on track, but by that time other geopolitical differences between the two sides made agreement more difficult and the negotiations more protracted.
The SALT II Treaty was finally signed at the summit meeting of President Carter and President Brezhnev at Vienna in June 1979. It provided equal levels of strategic arms (2,400, to be reduced over time to 2,200, strategic delivery vehicles) and included strategic bombers as well as strategic missiles. Intended to be in effect for ten years, during which a third SALT negotiation for further reductions was envisaged, the SALT II Treaty fell afoul of the collapse of the Soviet‐American detente of the 1970s after the Soviet occupation of Afghanistan in 1979, and was never ratified. Its major constraints, however, were formally observed by both sides until 1986, and for all practical purposes even thereafter.
Pursuant to the SALT I agreements a Standing Consultative Commission (SCC) was established to resolve questions regarding the meaning of and compliance with the SALT agreements. It was also stipulated that there would be no interference with the use of national technical means of verification, such as observation satellites. SALT thus helped at least to stabilize, if not greatly reduce, the military balance. The SALT process and the agreements reached, while causing some friction and disagreements, did contribute to the overall political detente of the 1970s. Although not sufficient to sustain that detente, the SALT process helped ensure that even under renewed tension the risk of nuclear war remained low.
The SALT process was a success in demonstrating that adversaries could reach arms limitation agreements. Nonetheless, owing to the very cautious and conservative approaches of both sides, the limitations on strategic offensive arms were unable to keep up with the military technological advances given precedence by the two countries. The SALT I Interim Agreement and the unratified SALT II Treaty did, however, bridge the period until later strategic arms reduction treaties (START) were reached in the early 1990s.
The ABM Treaty proved surprisingly durable over at least a quarter of a century. To be sure, it was challenged in the 1980s by advocates of President Ronald Reagan's Strategic Defense Initiative, and especially by an ill‐conceived attempt by the Reagan administration at unilateral reinterpretation to allow greater testing of space‐based ABM systems through a “broad interpretation” of the treaty, later repudiated. In the 1990s, a renewed interest in limited defense of the United States against possible missile proliferation or accidental missile launchings, and difficulty in defining the dividing line between strategic ABM systems limited by the treaty and tactical or theater ABM systems not limited by it, again posed a serious challenge. The ABM Treaty continues to be in effect and constitutes an important consideration in making possible the deep reductions in strategic offensive arms under the existing and contemplated START Treaties.
Overall, the SALT Treaties made a significant contribution to containing the dangers of the Cold War and provided a foundation for continuing arms control measures to reduce the risk of nuclear war.
[See also Arms Control and Disarmament; Cold War: External Course; Cuban Missile Crisis; Nuclear War, Prevention of Accidental.]
John Newhouse , Cold Dawn: The Story of SALT, 1973.
Strobe Talbott , Endgame: The Inside Story of SALT II, 1979.
Gerard C. Smith , Doubletalk: The Story of SALT I, 1980.
Coit D. Blacker and Gloria Duffy, eds., International Arms Control: Issues and Agreements, 2nd ed., 1984.
Raymond L. Garthoff