Carter and Brezhnev sign the SALT-II treaty - Jun 18, 1979 - HISTORY.com

During a summit meeting in Vienna, President Jimmy Carter and Soviet leader Leonid Brezhnev sign the SALT-II agreement dealing with limitations and guidelines for nuclear weapons. The treaty, which never formally went into effect, proved to be one of the most controversial U.S.-Soviet agreements of the Cold War.

The SALT-II agreement was the result of many nagging issues left over from the successful SALT-I treaty of 1972. Though the 1972 treaty limited a wide variety of nuclear weapons, many issues remained unresolved. Talks between the United States and the Soviet Union began almost immediately after SALT-I was ratified by both nations in 1972. Those talks failed to achieve any new breakthroughs, however. By 1979, both the United States and Soviet Union were eager to revitalize the process. For the United States, fear that the Soviets were leaping ahead in the arms race was the primary motivator. For the Soviet Union, the increasingly close relationship between America and communist China was a cause for growing concern.

In June 1979, Carter and Brezhnev met in Vienna and signed the SALT-II agreement. The treaty basically established numerical equality between the two nations in terms of nuclear weapons delivery systems. It also limited the number of MIRV missiles (missiles with multiple, independent nuclear warheads). In truth, the treaty did little or nothing to stop, or even substantially slow down, the arms race. Nevertheless, it met with unrelenting criticism in the United States. The treaty was denounced as a “sellout” to the Soviets, one that would leave America virtually defenseless against a whole range of new weapons not mentioned in the agreement. Even supporters of arms control were less than enthusiastic about the treaty, since it did little to actually control arms.

Debate over SALT-II in the U.S. Congress continued for months. In December 1979, however, the Soviets launched an invasion of Afghanistan. The Soviet attack effectively killed any chance of SALT-II being passed, and Carter ensured this by withdrawing the treaty from the Senate in January 1980. SALT-II thus remained signed, but unratified. During the 1980s, both nations agreed to respect the agreement until such time as new arms negotiations could take place.