United States nuclear weapon stockpile

United States nuclear weapon stockpile
Name	United States nuclear weapon stockpile
Country	United States of America
Administered by	Department of Defense, United States Department of Energy
First test	Trinity (nuclear test), 1945
First deployment	1945
Peak stockpile	~31,255 (1967)
Current estimate	~3,750 total warheads (2021 estimate)
Strategic delivery	Intercontinental ballistic missile, Submarine-launched ballistic missile
Tactical delivery	Air-to-surface missile, Gravity bomb

Contents

United States nuclear weapon stockpile is the collection of nuclear warheads and associated delivery vehicles maintained by the United States since 1945. The stockpile originated during World War II with the Manhattan Project and evolved through the Cold War into a triad of Intercontinental ballistic missile, Strategic bomber, and Submarine-launched ballistic missile capabilities managed by the United States Department of Defense and the United States Department of Energy. It has been shaped by testing programs, strategic doctrines such as deterrence theory, and bilateral and multilateral agreements including the Strategic Arms Reduction Treaty and the Non-Proliferation Treaty.

History and Development

The stockpile emerged from research institutions and programs such as the Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the Oak Ridge National Laboratory under the auspices of the Manhattan Project and later the Atomic Energy Commission. Early weapons development produced designs tested at locations like Trinity (nuclear test), Operation Crossroads, and the Nevada Test Site, while weapons effects were studied during series including Operation Ivy and Operation Castle. During the Cold War, force expansion reflected crises such as the Berlin Crisis of 1961, the Cuban Missile Crisis, and doctrine debates between advocates of mutual assured destruction and proponents of flexible response tied to planners at North American Aerospace Defense Command and Strategic Air Command. Modern stewardship transitioned from the Atomic Energy Commission to the Department of Energy and its National Nuclear Security Administration, while policy oversight involved administrations from Harry S. Truman through Joe Biden and legislative bodies such as the United States Congress.

Inventory accounting distinguishes deployed warheads on alert, reserve warheads in storage, and retired warheads awaiting dismantlement at facilities like the Pantex Plant and Y-12 National Security Complex. Historically, peak arsenals reached estimates in the tens of thousands during the 1960s, influenced by procurement programs at contractors including Lockheed Martin and Boeing and support from commands such as Air Force Global Strike Command. Current force structure centers on the nuclear triad: land-based LGM-30 Minuteman III ICBMs managed by Air Force Global Strike Command, sea-based Trident II (D5) SLBMs aboard Ohio-class submarines operated by United States Navy submarine squadrons, and bomber-delivered weapons deployed on platforms including the B-52 Stratofortress, B-2 Spirit, and the B-21 Raider. Tactical inventories historically included weapons for aircraft like the F-16 Fighting Falcon and delivery systems such as the AGM-86 ALCM. Stockpile numbers are influenced by treaty accounting from accords like the New START treaty and by domestic budgeting at the Office of Management and Budget.

Warhead designs span early fission devices such as the Fat Man-type implosion device and subsequent boosted fission and thermonuclear designs developed through programs at Los Alamos National Laboratory and Lawrence Livermore National Laboratory. Notable warheads include designs used in the W78, W88, W76, and B61 families, mated to delivery systems including the LGM-30 Minuteman III, UGM-133 Trident II, cruise missiles such as the AGM-86 ALCM, gravity bombs like the B61, and potential air-launched cruise missiles under modernization initiatives at Air Force Global Strike Command and United States Strategic Command. Delivery platforms have included strategic bombers like the B-52 Stratofortress and B-2 Spirit, and strategic submarines such as the Ohio-class submarine and planned Columbia-class submarine.

Safety and security regimes rely on technical measures developed at Sandia National Laboratories, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory, with material control supported by programs at the Y-12 National Security Complex and Los Alamos. Personnel vetting, coded permissive action links, and the Nuclear Command, Control, and Communications architecture integrate commands including United States Strategic Command and North American Aerospace Defense Command. Reliability assessments use non-explosive testing such as the Stockpile Stewardship Program, subcritical experiments at facilities like the Nevada National Security Site, and supercomputer simulations performed at centers including Lawrence Livermore National Laboratory's Sequoia (supercomputer) and Oak Ridge National Laboratory's Summit (supercomputer). Security policy engages interagency partners such as the Federal Bureau of Investigation and Department of Homeland Security.

Arms control frameworks affecting the stockpile have included the Treaty on the Non-Proliferation of Nuclear Weapons, the Strategic Arms Limitation Talks, the Strategic Arms Reduction Treaty, the Intermediate-Range Nuclear Forces Treaty, and New START. Policy debates involve administrations, the United States Congress, defense committees, and international interlocutors from Russia, China, and NATO allies. Verification and transparency measures use national technical means including reconnaissance platforms operated by National Reconnaissance Office and analysis by the Federation of American Scientists and think tanks such as the Brookings Institution and Center for Strategic and International Studies.

Modernization programs include warhead life-extension programs at Los Alamos National Laboratory and Lawrence Livermore National Laboratory, delivery system replacements such as the Ground Based Strategic Deterrent for LGM-30 Minuteman III, the Columbia-class submarine replacing the Ohio-class submarine, and the B-21 Raider for long-range bombing. Budget and procurement oversight involve the Department of Defense, the National Nuclear Security Administration, and congressional appropriations overseen by the United States Congress and Government Accountability Office. Debates over cost, strategic stability, and arms control continue to engage scholars at Harvard Kennedy School, Stanford University, and policy bodies including the Arms Control Association and the Nuclear Threat Initiative.