Long-Range Standoff

The Long-Range Standoff weapon (LRSO) is a U.S. Air Force program to develop a next-generation, nuclear-armed air-launched cruise missile (ALCM) carried by strategic bombers. It is designed to replace the aging AGM-86B ALCM, which entered service in the early 1980s and was originally intended for a much shorter service life. The LRSO is one pillar of the broader U.S. nuclear modernization effort, alongside the Sentinel ICBM (replacing Minuteman III), the Columbia-class ballistic missile submarine, and the B-21 Raider bomber.

"Standoff" refers to the missile's intended role: allowing bombers to launch from outside the range of advanced enemy air defenses, preserving the air leg of the nuclear triad against increasingly capable integrated air defense systems fielded by Russia and China. The weapon is intended to be carried by the B-52H and the forthcoming B-21 Raider, and is to be paired with the refurbished W80-4 warhead produced by the National Nuclear Security Administration.

Raytheon (now RTX) was selected as the sole contractor in 2020 after a competitive development phase that also included Lockheed Martin. The program has been a focal point of arms-control debate. Critics, including some former defense officials, have argued that a stealthy, dual-capable cruise missile is destabilizing because adversaries cannot readily distinguish nuclear from conventional variants in flight. Proponents, including successive Nuclear Posture Reviews, contend that LRSO is essential to credible extended deterrence and to the bomber leg's flexibility and recallability.

LRSO is not limited by the New START Treaty's deployed-warhead caps on ICBMs, SLBMs, and heavy bombers in the same direct way as silo-based systems, though bombers equipped to carry it count under that framework. The missile is also relevant to ongoing discussions about a possible future U.S.–Russia or trilateral arms-control regime that might address non-strategic and air-launched systems.