The United States was the first country to test an atomic bomb, with the Trinity test taking place in July 1945. It is also the only nation to use nuclear weapons in a conflict, dropping atomic bombs on Hiroshima and Nagasaki. From 1945 to 1992, the United States conducted 1,032 nuclear tests, most of which occurred underground after the Limited Test Ban Treaty was signed in 1963. The United States signed and ratified the Nuclear Non-Proliferation Treaty in 1968. In doing so, the nation agreed to pursue negotiations and reductions in good faith, with the eventual goal of complete nuclear disarmament.
The United States has a total nuclear inventory of 5,800 nuclear warheads, with around 3,800 active warheads in the stockpile and 2,000 retired warheads awaiting dismantlement. These weapons are deployed on air, sea, and land platforms in what is referred to as “The Triad.” At its peak, the United States had more than 31,000 nuclear weapons in its stockpile. Through various arms control agreements and unilateral reductions, the United States currently complies with New START levels: 1,550 nuclear warheads on 800 strategic launchers, only 700 of which can be deployed. It also allows each nation to conduct 18 on-site inspections per year.