Nuclear weapons of the United States

Nuclear weapons of the United States
source
Name	United States nuclear arsenal
Origin	United States
Type	Strategic and tactical nuclear weapons
In service	1945–present
Designer	Manhattan Project, Los Alamos National Laboratory, Lawrence Livermore National Laboratory
Wars	World War II

Contents

Nuclear weapons of the United States are the nuclear explosive devices developed, tested, produced, and maintained by the United States since 1945. They were first used in Hiroshima and Nagasaki under the direction of the Manhattan Project and have since been central to policies shaped by figures such as Harry S. Truman, Dwight D. Eisenhower, John F. Kennedy, and Ronald Reagan. US nuclear forces evolved through institutions including Los Alamos National Laboratory, Sandia National Laboratories, Lawrence Livermore National Laboratory, and production sites like the Oak Ridge National Laboratory and Hanford Site.

History and development

Early development began with the Manhattan Project, led by scientists such as J. Robert Oppenheimer, Enrico Fermi, Edward Teller, and administrators like Leslie Groves. The first test, Trinity (1945), preceded operational use at Hiroshima and Nagasaki in World War II under President Harry S. Truman. In the early Cold War decades, programs at Los Alamos National Laboratory and Lawrence Livermore National Laboratory produced designs such as the ""Fat Man"" and ""Little Boy"", followed by thermonuclear designs influenced by Stanislaw Ulam and Edward Teller leading to tests like Ivy Mike and Operation Castle. Industrial expansion occurred at sites including Rocky Flats Plant, Y-12 National Security Complex, and Pantex Plant with oversight from agencies like the Atomic Energy Commission and later the Department of Energy in coordination with the Department of Defense. Nuclear doctrine shifted during crises such as the Berlin Blockade, Korean War, Cuban Missile Crisis, and Vietnam War, prompting programs including the Strategic Air Command modernizations and the development of delivery systems from B-29 Superfortress to Minuteman III and Trident II (D5). The post–Cold War era involved stockpile reductions under leaders like George H. W. Bush and Bill Clinton and stewardship programs such as the Stockpile Stewardship Program.

The US arsenal comprises strategic and tactical warheads deployed on platforms like LGM-30 Minuteman III ICBMs, UGM-133 Trident II SLBMs aboard Ohio-class submarines, and aircraft such as the B-52 Stratofortress, B-2 Spirit, and B-21 Raider. Warhead designs include the W76, W88, W78, and tactical variants like the B61 family, developed at Lawrence Livermore National Laboratory and Los Alamos National Laboratory with plutonium pits produced at Los Alamos National Laboratory and Kansas City National Security Campus. Modernization programs managed by the National Nuclear Security Administration and contractors such as Lockheed Martin, Boeing, and Northrop Grumman include the Ground Based Strategic Deterrent, Columbia-class submarine, and life-extension programs for W87 and W88 warheads. Air-launched cruise missiles like the AGM-86 ALCM and future systems connect to platforms maintained by units such as Air Force Global Strike Command, while nuclear-capable fighter and bomber forces trace lineage to Strategic Air Command and Tactical Air Command antecedents.

US nuclear command and control centers on civilian and military leadership including the President of the United States, the Secretary of Defense, and strategic commanders like the United States Strategic Command. Communication and authority pass through systems such as the Nuclear Command, Control, and Communications (NC3), the National Military Command Center, and airborne assets like the E-4 Advanced Airborne Command Post and E-6 Mercury. Deployment posture has varied with policies announced by administrations including Richard Nixon, Jimmy Carter, Ronald Reagan, George W. Bush, and Barack Obama; changes have responded to treaties such as the Strategic Arms Reduction Treaty and geopolitical events like the Soviet–Afghan War and September 11 attacks. Alert status adjustments reference Cold War frames including DEFCON and force readiness exercised in operations like Global Thunder and historical tests such as Operation Dominic.

US nuclear strategy evolved from early concepts of massive retaliation advocated by officials in the Eisenhower administration to the flexible response posture of the Kennedy administration and later doctrines of mutual assured destruction debated during the Cold War. Theories developed by strategists such as Thomas Schelling, Albert Wohlstetter, and institutions like the Rand Corporation influenced targeting policies including counterforce, countervalue, and limited options. Declaratory policy has been shaped by documents like the Nuclear Posture Review under presidents including Bill Clinton, George W. Bush, Barack Obama, and Donald Trump, and incorporates considerations from legal instruments such as the Treaty on the Non-Proliferation of Nuclear Weapons and discussions in forums like the United Nations Security Council.

Nuclear testing programs from Operation Crossroads to Operation Ivy, Operation Dominic, and atmospheric tests at sites like Bikini Atoll and Enewetak led to public controversy and environmental effects documented by entities including the National Research Council and Centers for Disease Control and Prevention. The 1963 Partial Test Ban Treaty and the 1992 cessation of testing followed the Comprehensive Nuclear-Test-Ban Treaty negotiations, while safety and maintenance have been governed by the Stockpile Stewardship Program and facilities like the National Ignition Facility. Security measures against theft or sabotage involve coordination among the National Nuclear Security Administration, Federal Bureau of Investigation, Department of Homeland Security, and commands such as United States Northern Command, with legacy issues including contamination at sites like Hanford Site and cleanup managed by the Environmental Protection Agency.

US policies on proliferation and arms control engaged treaties like the Treaty on the Non-Proliferation of Nuclear Weapons, Strategic Arms Limitation Talks, Strategic Arms Reduction Treaty, and the New START treaty with the Russian Federation. Diplomacy involved negotiations with states such as the Soviet Union, United Kingdom, France, and China and multilateral efforts in forums like the International Atomic Energy Agency and United Nations General Assembly. US export controls and nonproliferation initiatives intersect with incidents such as the A.Q. Khan network revelations and agreements like the Nuclear Suppliers Group. Debates continue within policy circles including members of Congress and advisory bodies such as the Presidential Advisory Council on Science and Technology over modernization, disarmament advocacy by groups like International Physicians for the Prevention of Nuclear War, and compliance verification mechanisms monitored by organizations including Verification Research, Training and Information Centre.

Category:United States military history