The START (Strategic Arms Reduction Treaty) was a nuclear arms reduction treaty signed by the United States and the Soviet Union on July 31, 1991. The treaty was designed to reduce the number of strategic nuclear weapons deployed by both countries, and it was a follow-up to the earlier Intermediate-Range Nuclear Forces Treaty (INF) and the Anti-Ballistic Missile Treaty (ABM).
Under the START treaty, both the United States and the Soviet Union agreed to reduce their deployed strategic nuclear warheads to 6,000 each, as well as limit the number of land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers. The treaty also established a system of monitoring and verification to ensure that both sides were complying with the terms of the agreement.
The START treaty was seen as a major milestone in the efforts to reduce the nuclear arsenals of both countries, and it paved the way for further arms control agreements in the years that followed. The treaty remained in force until 2009 when it was superseded by the New START treaty, which further reduced the number of deployed strategic nuclear warheads to 1,550 for each side.