1、 https:/crsreports.congress.gov Updated March 29, 2022Defense Primer: Strategic Nuclear ForcesThe Nuclear Triad Since the early 1960s the United States has maintained a “triad” of strategic nuclear delivery vehicles. These include long-range land-based intercontinental ballistic missiles (ICBMs), lo
2、ng-range submarine-launched ballistic missiles (SLBMs), and long-range heavy bombers equipped to carry nuclear-armed cruise missiles and gravity bombs. The number of nuclear warheads carried on these delivery vehicles peaked in the late 1980s, at around 14,000 warheads. It has been declining ever si
3、nce, both as the United States complies with limits in U.S.-Russian arms control agreements and as it has changed requirements after the Cold War. As of February 2018, the United States had reduced its forces to comply with the New START Treaty, which entered into force in early 2011. Table 1 displa
4、ys the U.S. forces that count under the treaty limits, as of September 1, 2020. These forces fall below the treaty limits of 1,550 deployed warheads on 700 deployed missiles due to maintenance schedules and operational requirements. An update released in September 2021 indicated that the United Stat
