United States nuclear weapons

United States nuclear weapons
Country	United States
Program start	1942 (Manhattan Project)
First test	16 July 1945 (Trinity)
First fusion test	1 November 1952 (Ivy Mike)
Last test	23 September 1992 (Divider)
Largest yield	15 Mt (Castle Bravo)
Total tests	1,054 detonations
Peak stockpile	31,255 warheads (1967)
Current stockpile	~3,750 active warheads (2024 est.)
Current strategic	~1,550 deployed strategic warheads
Delivery methods	ICBMs, SLBMs, strategic bombers
Max range	>13,000 km (Minuteman III)
NPT signer	Yes (1968, one of five recognized states)

United States nuclear weapons constitute the world's second-largest stockpile of nuclear warheads and form the cornerstone of its national defense strategy. The program originated with the top-secret Manhattan Project during World War II, leading to the first-ever nuclear detonation, Trinity, in 1945. Since then, the arsenal has evolved through numerous technological generations, governed by a complex framework of policies and treaties, and remains a central element of global strategic stability.

History

The development of the first atomic bomb was driven by fears that Nazi Germany was pursuing similar research, culminating in the establishment of the Manhattan Project under the command of General Leslie Groves and scientific direction of J. Robert Oppenheimer. Following the success of the Trinity test in New Mexico, the United States employed two weapons against Japan: Little Boy on Hiroshima and Fat Man on Nagasaki, leading to the end of World War II. The subsequent Cold War ignited a fierce arms race with the Soviet Union, marked by the Soviet's first test in 1949 and the United States' development of the more powerful thermonuclear weapon in 1952 with Ivy Mike. Key events shaping the arsenal's history include the Cuban Missile Crisis, the signing of the Partial Nuclear Test Ban Treaty, and the strategic arms limitation talks that produced agreements like SALT I and New START.

Types and yields

The United States nuclear arsenal encompasses a wide range of warhead types and delivery systems, designed for various strategic and tactical roles. Strategic weapons include high-yield warheads carried by ICBMs like the LGM-30G Minuteman III, SLBMs such as the UGM-133 Trident II, and air-launched bombs and missiles deployed on strategic bombers like the B-52 Stratofortress and B-2 Spirit. Yields range from sub-kiloton devices, such as the B61 mod 3 and mod 4, to multi-megaton warheads that were historically deployed on systems like the Titan II. The majority of the current stockpile consists of lower-yield, precision-guided weapons, reflecting a shift from massive retaliation to more flexible options.

Command and control

Authority to order the use of nuclear weapons rests solely with the President of the United States, who is accompanied at all times by a military aide carrying the Nuclear football. The command chain flows through the United States Department of Defense, specifically the United States Strategic Command (USSTRATCOM) at Offutt Air Force Base. Execution orders would be transmitted via secure communications networks like the Minimum Essential Emergency Communications Network to launch crews in silos, submarines, and bomber bases. This system is designed with multiple safeguards, including rigorous authentication procedures and the two-man rule, to prevent unauthorized or accidental use.

Stockpile and deployment

The active stockpile is estimated to consist of approximately 3,750 warheads, with around 1,550 deployed on strategic delivery systems as counted under New START. These are fielded in a nuclear triad: 400 Minuteman III ICBMs in silos across F.E. Warren, Malmstrom, and Minot Air Force Base; 14 Ohio-class ballistic missile submarines armed with Trident missiles; and strategic bombers at bases like Barksdale Air Force Base and Whiteman Air Force Base. Several hundred additional warheads are held in reserve, and a larger number are retired and awaiting dismantlement. The stockpile is managed by the National Nuclear Security Administration under the United States Department of Energy.

Testing and development

From 1945 to 1992, the United States conducted 1,054 nuclear tests, primarily at the Nevada Test Site and the Pacific Proving Grounds. Notable tests include the first thermonuclear device, Ivy Mike; the largest U.S. test, Castle Bravo; and the Vela Incident. The 1992 signing of the Comprehensive Nuclear-Test-Ban Treaty (though not ratified by the U.S. Senate) led to a moratorium on explosive testing. Since then, warhead reliability and safety have been maintained through the Stockpile Stewardship Program, utilizing advanced supercomputers at facilities like Lawrence Livermore National Laboratory and subcritical experiments at the Nevada National Security Site. Modern development efforts focus on life-extension programs for existing warheads and new designs like the W93.

Policy and doctrine

U.S. nuclear policy is formally articulated in documents like the Nuclear Posture Review and has evolved from doctrines of Massive retaliation and Mutual assured destruction (MAD) during the Cold War to more nuanced strategies. Current policy, as stated in the 2022 Nuclear Posture Review, emphasizes deterrence of strategic attacks, assurance of allies, and achievement of U.S. objectives if deterrence fails, while seeking to reduce the role of nuclear weapons. The United States maintains a policy of neither confirming nor denying their presence aboard specific vessels. It is a signatory to key treaties including the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), New START, and the Intermediate-Range Nuclear Forces Treaty (now defunct), and provides a security umbrella to allies like those in NATO under its policy of Extended deterrence.

Category:Nuclear weapons of the United States Category:Nuclear weapons by country Category:Military of the United States