The Soviet Union under Gorbachev has embarked on a fundamentally new policy of nuclear disarmament. The pursuit of arms limitation has been replaced by arms reduction. Control of nuclear weapons in the 1970s and early 1980s merely regulated superpower rivalry. The first Strategic Arms Limitation Treaty (SALT I) imposed ceilings on an approximate balance in the number of weapons, and SALT I codified parity in nuclear potentials. In contrast, the USSR is now collaborating with the United States to make substantial cuts in nuclear stockpiles, to eliminate certain categories of weapons, and to restructure Soviet nuclear forces.
Before Gorbachev's accession, the Soviet Union insisted on preserving its newly acquired advantages in theater nuclear weapons, opposed significant cuts in its strategic arsenal, and refused to allow any research into space-based defenses. By 1990, the USSR was eliminating all of its intermediate- and short-range missiles, pressing for reduction of tactical nuclear weapons, agreeing to substantial cuts in strategic arms and intercontinental land-based missiles, and permitting some research and testing related to space weapons. Rather than seeking to protect Soviet gains, the Gorbachev leadership entered negotiations in order to restrain competition in nuclear arms. It made the bulk of the concessions and relinquished some of its advantages to reach agreement with the United States. Whereas the Brezhnev Polit