During the late 1960s, the United States learned that the Soviet Union had embarked upon a massive
Intercontinental Ballistic Missile (ICBM) buildup designed to reach parity with the United States. In January 1967,
President Lyndon Johnson announced that the Soviet Union had begun to construct a limited Anti-Ballistic
Missile (ABM) defense system around Moscow. The development of an ABM system could allow one side to
launch a first strike and then prevent the other from retaliating by shooting down incoming missiles.
Johnson therefore called for strategic arms limitations talks (SALT), and in 1967, he and Soviet Premier Alexei
Kosygin met at Glassboro State College in New Jersey. Johnson said they must gain “control of the ABM race,”
and Secretary of Defense Robert McNamara argued that the more each reacted to the other’s escalation, the
more they had chosen “an insane road to follow.” While abolition of nuclear weapons would be impossible,
limiting the development of both offensive and defensive strategic systems would stabilize U.S.-Soviet relations.

Johnson’s successor, Richard Nixon, also believed in SALT, and on November 17, 1969, the formal SALT talks began in Helsinki, Finland. Over the next two and a half years, the two sides haggled over whether or not each nation
should complete their plans for ABMs; verification of a treaty; and U.S. concern that the Soviets continued to build more
Submarine-Launched Ballistic Missiles (SLBMs). Nixon and Soviet General Secretary Leonid Brezhnev signed the ABM Treaty and interim SALT agreement on May 26, 1972, in Moscow.

For the first time during the Cold War, the United States and Soviet Union had agreed to limit the number of nuclear missiles in their arsenals. SALT I is considered the crowning achievement of the Nixon-Kissinger strategy of détente. The ABM Treaty limited strategic missile defenses to 200 interceptors each and allowed each side to construct two missile
defense sites, one to protect the national capital, the other to protect one ICBM field. (For financial and strategic
reasons, the United States stopped construction of each by the end of the decade.)

SALT II

Negotiations for a second round of SALT began in late 1972. Since SALT I did not prevent each side from
enlarging their forces through the deployment of Multiple Independently Targeted Re-Entry Vehicles (MIRVs)
onto their ICBMs and SLBMs, SALT II initially focused on limiting, and then ultimately reducing, the number of
Nixon and Brezhnev during the latter’s visit to the U.S. in 1973. (Nixon Presidential Library)
MIRVs. Negotiations also sought to prevent both sides from making qualitative breakthroughs that would again
destabilize the strategic relationship. The negotiations spanned the Nixon, Gerald Ford, and Jimmy Carter
administrations.

At the November 1974 Vladivostok Summit, Ford and Brezhnev agreed on the basic framework of a SALT II
agreement. This included a 2,400 limit on strategic nuclear delivery vehicles (ICBMs, SLBMs, and heavy bombers)
for each side; a 1,320 limit on MIRV systems; a ban on new land-based ICBM launchers; and limits on
deployment of new types of strategic offensive arms.

Even after the Vladivostok agreements, the two nations could not resolve the two other outstanding issues from
SALT I: the number of strategic bombers and the total number of warheads in each nation’s arsenal. The first
was complicated by the Soviet Backfire bomber, which U.S. negotiators believed could reach the United States
but which the Soviets refused to include in the SALT negotiations. Meanwhile, the Soviets attempted
unsuccessfully to limit American deployment of Air-Launched Cruise Missiles (ALCMs). Verification also divided
the two nations, but eventually they agreed on using National Technical Means (NTM), including the collection
of electronic signals known as telemetry and the use of photo-reconnaissance satellites. On June 17, 1979,
Carter and Brezhnev signed the SALT II Treaty in Vienna. SALT II limited the total of both nations’ nuclear forces
to 2,250 delivery vehicles and placed a variety of other restrictions on deployed strategic nuclear forces,
including MIRVs.

However, a broad coalition of Republicans and conservative Democrats grew increasingly skeptical of the Soviet
Union’s crackdown on internal dissent, its increasingly interventionist foreign policies, and the verification
process delineated in the Treaty. On December 17, 1979, 19 Senators wrote Carter that “Ratification of a SALT II
Treaty will not reverse trends in the military balance adverse to the United States.” On December 25, the Soviets
invaded Afghanistan, and on January 3, 1980, Carter asked the Senate not to consider SALT II for its advice and
consent, and it was never ratified. Both Washington and Moscow subsequently pledged to adhere to the
agreement’s terms despite its failure to enter into force. Carter’s successor Ronald Reagan, a vehement critic of
SALT II during the 1980 presidential campaign, agreed to abide by SALT II until its expiration on December 31,
1985, while he pursued the Strategic Arms Reduction Treaty (START) and argued that research into the Strategic
Defense Initiative (SDI) adhered to the 1972 ABM Treaty