The UGM-27 Polaris missile was a two-stage solid-fueled nuclear-armed submarine-launched ballistic missile (SLBM). As the United States Navy's first SLBM, it served from 1961 to 1980.
Nuclear warfare, also known as atomic warfare, is a theoretical military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear warfare can produce destruction in a much shorter time and can have a long-lasting radiological result. A major nuclear exchange would likely have long-term effects, primarily from the fallout released, and could also lead to secondary effects, such as "nuclear winter", nuclear famine and societal collapse. A global thermonuclear war with Cold War-era stockpiles, or even with the current smaller stockpiles, may lead to various scenarios including the extinction of the human race.
A permissive action link (PAL) is an access control security device for nuclear weapons. Its purpose is to prevent unauthorized arming or detonation of a nuclear weapon. The United States Department of Defense definition is:
A device included in or attached to a nuclear weapon system to preclude arming and/or launching until the insertion of a prescribed discrete code or combination. It may include equipment and cabling external to the weapon or weapon system to activate components within the weapon or weapon system.
The Bulletin of the Atomic Scientists is a nonprofit organization concerning science and global security issues resulting from accelerating technological advances that have negative consequences for humanity. The Bulletin publishes content at both a free-access website and a bi-monthly, nontechnical academic journal. The organization has been publishing continuously since 1945, when it was founded by former Manhattan Project scientists as the Bulletin of the Atomic Scientists of Chicago immediately following the atomic bombings of Hiroshima and Nagasaki. The organization is also the keeper of the symbolic Doomsday Clock, the time of which is announced each January.
The United States is known to have possessed three types of weapons of mass destruction: nuclear weapons, chemical weapons, and biological weapons. The U.S. is the only country to have used nuclear weapons on another country, when it detonated two atomic bombs over two Japanese cities of Hiroshima and Nagasaki during World War II. It had secretly developed the earliest form of the atomic weapon during the 1940s under the title "Manhattan Project". The United States pioneered the development of both the nuclear fission and hydrogen bombs. It was the world's first and only nuclear power for four years, from 1945 until 1949, when the Soviet Union produced its own nuclear weapon. The United States has the second-largest number of nuclear weapons in the world, after the Russian Federation.
The People's Republic of China has developed and possesses weapons of mass destruction, including chemical and nuclear weapons. The first of China's nuclear weapons tests took place in 1964, and its first hydrogen bomb test occurred in 1967. Tests continued until 1996, when China signed the Comprehensive Test Ban Treaty (CTBT). China has acceded to the Biological and Toxin Weapons Convention (BWC) in 1984 and ratified the Chemical Weapons Convention (CWC) in 1997.
Pakistan is one of nine states to possess nuclear weapons. Pakistan began development of nuclear weapons in January 1972 under Prime Minister Zulfikar Ali Bhutto, who delegated the program to the Chairman of the Pakistan Atomic Energy Commission (PAEC) Munir Ahmad Khan with a commitment to having the device ready by the end of 1976. Since PAEC, which consisted of over twenty laboratories and projects under reactor physicist Munir Ahmad Khan, was falling behind schedule and having considerable difficulty producing fissile material, Abdul Qadeer Khan, a metallurgist working on centrifuge enrichment for Urenco, joined the program at the behest of the Bhutto administration by the end of 1974. As pointed out by Houston Wood, "The most difficult step in building a nuclear weapon is the production of fissile material"; as such, this work in producing fissile material as head of the Kahuta Project was pivotal to Pakistan developing the capability to detonate a nuclear weapon by the end of 1984.
The United States was the first country to manufacture nuclear weapons and is the only country to have used them in combat, with the bombings of Hiroshima and Nagasaki in World War II. Before and during the Cold War, it conducted 1,054 nuclear tests, and tested many long-range nuclear weapons delivery systems.
The W80 is a low to intermediate yield two-stage thermonuclear warhead deployed by the U.S. enduring stockpile with a variable yield ("dial-a-yield") of 5 or 150 kilotonnes of TNT.
The W76 is an American thermonuclear warhead, designed for use on the UGM-96 Trident I submarine-launched ballistic missiles (SLBMs) and subsequently moved to the UGM-133 Trident II as Trident I was phased out of service. The first variant, the W76 mod 0 (W76-0) was manufactured from 1978 to 1987, and was gradually replaced by the W76 mod 1 (W76-1) between 2008 and 2018, completely replacing the Mod 0 in the active stockpile. In 2018 it was announced that some Mod 1 warheads would be converted to a new low-yield W76 mod 2 (W76-2) version. The first Mod 2 warheads were deployed in late 2019.
Nuclear weapons delivery is the technology and systems used to place a nuclear weapon at the position of detonation, on or near its target. Several methods have been developed to carry out this task.
The W87 is an American thermonuclear missile warhead formerly deployed on the LGM-118A Peacekeeper ("MX") ICBM. 50 MX missiles were built, each carrying up to 10 W87 warheads in multiple independently targetable reentry vehicles (MIRV), and were deployed from 1986 to 2005. Starting in 2007, 250 of the W87 warheads from retired Peacekeeper missiles were retrofitted onto much older Minuteman III missiles, with one warhead per missile.
The W47 was an American thermonuclear warhead used on the Polaris A-1 sub-launched ballistic missile system. Various models were in service from 1960 through the end of 1974. The warhead was developed by the Lawrence Radiation Laboratory between 1957 and 1960.
The Reliable Replacement Warhead (RRW) was a proposed new American nuclear warhead design and bomb family that was intended to be simple, reliable and to provide a long-lasting, low-maintenance future nuclear force for the United States. Initiated by the United States Congress in 2004, it became a centerpiece of the plans of the National Nuclear Security Administration (NNSA) to remake the nuclear weapons complex.
A nuclear triad is a three-pronged military force structure that consists of land-launched nuclear missiles, nuclear-missile-armed submarines, and strategic aircraft with nuclear bombs and missiles. Specifically, these components are land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and strategic bombers. The purpose of having this three-branched nuclear capability is to significantly reduce the possibility that an enemy could destroy all of a nation's nuclear forces in a first-strike attack. This, in turn, ensures a credible threat of a second strike, and thus increases a nation's nuclear deterrence.
Trident, also known as the Trident nuclear programme or Trident nuclear deterrent, covers the development, procurement and operation of nuclear weapons in the United Kingdom and their means of delivery. Its purpose as stated by the Ministry of Defence is to "deter the most extreme threats to our national security and way of life, which cannot be done by other means". Trident is an operational system of four Vanguard-class submarines armed with Trident II D-5 ballistic missiles, able to deliver thermonuclear warheads from multiple independently targetable re-entry vehicles (MIRVs). It is operated by the Royal Navy and based at Clyde Naval Base on the west coast of Scotland. At least one submarine is always on patrol to provide a continuous at-sea capability. Each one carries no more than eight missiles and forty warheads, although their capacity is higher. The missiles are manufactured in the United States, while the warheads are British.
Nuclear history of the United States describes the history of nuclear affairs in the United States whether civilian or military.
The State of Israel is widely believed to possess nuclear weapons. Estimates of Israel's stockpile range between 80 and 400 nuclear warheads, and the country is believed to possess the ability to deliver them in several methods, including by aircraft, as submarine-launched cruise missiles, and via the Jericho series of intermediate to intercontinental range ballistic missiles. Its first deliverable nuclear weapon is thought to have been completed in late 1966 or early 1967; which would make it the sixth country in the world to have developed them.
The National Nuclear Security Administration (NNSA) is a United States federal agency responsible for safeguarding national security through the military application of nuclear science. NNSA maintains and enhances the safety, security, and effectiveness of the U.S. nuclear weapons stockpile; works to reduce the global danger from weapons of mass destruction; provides the United States Navy with safe and effective nuclear propulsion; and responds to nuclear and radiological emergencies in the United States and abroad.
