Nuclear weapons and the United Kingdom

Nuclear weapons and the United Kingdom

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The United Kingdom was the third country to test an independently developed nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...

, in October 1952. It is one of the five "Nuclear Weapons States" (NWS) under the Nuclear Non-Proliferation Treaty
Nuclear Non-Proliferation Treaty
The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT, is a landmark international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy and to...

, which the UK ratified in 1968. The UK is currently thought to retain a weapons stockpile of around 160 operational nuclear warhead
Warhead
The term warhead refers to the explosive material and detonator that is delivered by a missile, rocket, or torpedo.- Etymology :During the early development of naval torpedoes, they could be equipped with an inert payload that was intended for use during training, test firing and exercises. This...

s and 225 nuclear warheads in total but has refused to declare exact size of its arsenal.

Since the 1958 US-UK Mutual Defence Agreement
1958 US-UK Mutual Defence Agreement
The 1958 US–UK Mutual Defence Agreement is a bilateral treaty between the United States and the United Kingdom on nuclear weapons cooperation.It was signed after the UK successfully tested its first hydrogen bomb during Operation Grapple. While the U.S...

, the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and the United Kingdom have cooperated extensively on nuclear security matters. The special relationship
Special relationship
The Special Relationship is a phrase used to describe the exceptionally close political, diplomatic, cultural, economic, military and historical relations between the United Kingdom and the United States, following its use in a 1946 speech by British statesman Winston Churchill...

 between the two countries has involved the exchange of classified scientific information and nuclear materials such as plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...

. The UK has not run an independent nuclear weapons delivery system development and production programme since the cancellation of the Blue Streak missile
Blue Streak missile
The Blue Streak missile was a British medium range ballistic missile . The Operational Requirement for the missile was issued in 1955 and the design was complete by 1957...

 in the 1960s, instead it has pursued joint development (for its own use) of US delivery systems, designed and manufactured by Lockheed Martin
Lockheed Martin
Lockheed Martin is an American global aerospace, defense, security, and advanced technology company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area....

, and fitting them with warheads designed and manufactured by the UK's Atomic Weapons Research Establishment and its successor the Atomic Weapons Establishment
Atomic Weapons Establishment
The Atomic Weapons Establishment is responsible for the design, manufacture and support of warheads for the United Kingdom's nuclear deterrent. AWE plc is responsible for the day-to-day operations of AWE...

. In 1974 a US proliferation assessment noted that "In many cases [Britain's sensitive technology in nuclear and missile fields] is based on technology received from the US and could not legitimately be passed on without US permission."

In contrast with the other permanent members of the United Nations Security Council
United Nations Security Council
The United Nations Security Council is one of the principal organs of the United Nations and is charged with the maintenance of international peace and security. Its powers, outlined in the United Nations Charter, include the establishment of peacekeeping operations, the establishment of...

, the United Kingdom currently operates only a single nuclear weapon delivery system since decommissioning its tactical WE.177
WE.177
WE.177 was the last air-delivered tactical nuclear weapon of the British Armed Forces. There were three versions; WE.177A was a boosted fission weapon, while WE.177B and WE.177C were thermonuclear weapons...

 free-falling nuclear bombs in 1998. The present system consists of four Vanguard class
Vanguard class submarine
The Vanguard class are the Royal Navy's current nuclear ballistic missile submarines , each armed with up to 16 Trident II Submarine-launched ballistic missiles...

 submarines based at HMNB Clyde
HMNB Clyde
Her Majesty's Naval Base Clyde is one of three operating bases in the United Kingdom for the Royal Navy...

, armed with up to 16 Trident missile
Trident missile
The Trident missile is a submarine-launched ballistic missile equipped with multiple independently-targetable reentry vehicles . The Fleet Ballistic Missile is armed with nuclear warheads and is launched from nuclear-powered ballistic missile submarines . Trident missiles are carried by fourteen...

s, which each carry nuclear warheads in up to eight MIRVs
Multiple independently targetable reentry vehicle
A multiple independently targetable reentry vehicle warhead is a collection of nuclear weapons carried on a single intercontinental ballistic missile or a submarine-launched ballistic missile . Using a MIRV warhead, a single launched missile can strike several targets, or fewer targets redundantly...

, performing both strategic
Military strategy
Military strategy is a set of ideas implemented by military organizations to pursue desired strategic goals. Derived from the Greek strategos, strategy when it appeared in use during the 18th century, was seen in its narrow sense as the "art of the general", 'the art of arrangement' of troops...

 and sub-strategic
Tactical nuclear weapon
A tactical nuclear weapon refers to a nuclear weapon which is designed to be used on a battlefield in military situations. This is as opposed to strategic nuclear weapons which are designed to menace large populations, to damage the enemy's ability to wage war, or for general deterrence...

 deterrence roles.

While a firm decision has yet to be taken on the replacement of the UK's nuclear weapons, the manufacturer of the UK's warheads, AWE
Atomic Weapons Establishment
The Atomic Weapons Establishment is responsible for the design, manufacture and support of warheads for the United Kingdom's nuclear deterrent. AWE plc is responsible for the day-to-day operations of AWE...

, is currently undertaking research which is largely dedicated to providing new warheads and on 4 December 2006 the then Prime Minister Tony Blair
Tony Blair
Anthony Charles Lynton Blair is a former British Labour Party politician who served as the Prime Minister of the United Kingdom from 2 May 1997 to 27 June 2007. He was the Member of Parliament for Sedgefield from 1983 to 2007 and Leader of the Labour Party from 1994 to 2007...

 announced plans for a new class of nuclear missile submarines
British replacement of the Trident system
The British replacement of Trident is a proposal to replace the existing Vanguard class of four Trident ballistic-missile armed submarines with a new class designed to continue a nuclear deterrent after the current boats reach the end of their service lives...

.

Number of warheads



In the Strategic Defence Review published in July 1998, the United Kingdom government stated that once the Vanguard submarines became fully operational (the fourth and final one, Vengeance
HMS Vengeance (S31)
HMS Vengeance is the fourth and final of the Royal Navy. Vengeance carries the Trident ballistic missile, the UK's nuclear deterrent....

, entered service on 27 November 1999), it would "maintain a stockpile of fewer than 200 operationally available warheads". The Stockholm International Peace Research Institute has estimated the figure as about 165, consisting of 144 deployed weapons plus an extra 15 percent as spares.

At the same time, the UK government indicated that warheads "required to provide a necessary processing margin and for technical surveillance purposes" were not included in the "fewer than 200" figure. However, as recently declassified archived documents on Chevaline
Chevaline
Chevaline was a system to improve the penetrability of the British Polaris missile warheads. Devised as an answer to the improved Soviet defences around Moscow, the system was intended to increase the probability that at least one warhead would penetrate the city's anti-ballistic missile defences,...

 make clear, the 15% excess (referred to by SIPRI as for spares) is normally intended to provide the 'necessary processing margin', and 'surveillance rounds do not contain any nuclear material, being completely inert. These surveillance rounds are used to monitor deterioration in the many non-nuclear components of the warhead, and are best compared with inert training rounds. The SIPRI figures correspond accurately with the official announcements and are likely to be the most accurate. The Natural Resources Defense Council
Natural Resources Defense Council
The Natural Resources Defense Council is a New York City-based, non-profit, non-partisan international environmental advocacy group, with offices in Washington DC, San Francisco, Los Angeles, Chicago, and Beijing...

 speculates that a figure of 200 is accurate to within a few tens. In 2008 the National Audit Office
National Audit Office (United Kingdom)
The National Audit Office is an independent Parliamentary body in the United Kingdom which is responsible for auditing central government departments, government agencies and non-departmental public bodies...

 stated that the UK stockpile was of fewer than 160 operationally available nuclear warheads.
During a debate on the Queen's Speech on 26 May 2010 Foreign Secretary William Hague
William Hague
William Jefferson Hague is the British Foreign Secretary and First Secretary of State. He served as Leader of the Conservative Party from June 1997 to September 2001...

 reiterated that the UK has no more than 160 operationally available warheads, and announced that the total number will not exceed 225.

Weapons tests


Different sources give the number of test explosions that the UK has conducted as either 44 or 45. The 24 tests from December 1962 onwards were in conjunction with the United States at the Nevada Test Site
Nevada Test Site
The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...

 with the final test being the Julin Bristol
Julin Bristol
Julin Bristol was the last British nuclear test, and took place at the Nevada Test Site on 26 November 1991. With a yield of less than 20 kilotons it may have been a proof test of some aspect of the British-designed warheads fitted to those Trident missiles in the British arsenal, possibly of a...

 shot which took place on 26 November 1991. The apparently low numbers of UK tests is misleading when compared to the large numbers of tests carried out by the US, the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

, and especially France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

; because the UK has had extensive access to US test data, obviating the need for UK tests: and an added factor is that many tests required are for 'weapon effects tests'; tests not of the nuclear device itself, but of the nuclear effects on hardened components designed to resist ABM attack. Numerous such 'effects' tests were done in support of the Chevaline
Chevaline
Chevaline was a system to improve the penetrability of the British Polaris missile warheads. Devised as an answer to the improved Soviet defences around Moscow, the system was intended to increase the probability that at least one warhead would penetrate the city's anti-ballistic missile defences,...

 programme especially; and there is some evidence that some were permitted for the French programme to harden their RVs and warheads; because most French tests being under the ocean floor, access to measure 'weapon effects' was nigh impossible. An independent test programme would see the UK numbers soar to French levels. The UK government signed the Partial Test Ban Treaty
Partial Test Ban Treaty
The treaty banning nuclear weapon tests in the atmosphere, in outer space and under water, often abbreviated as the Partial Test Ban Treaty , Limited Test Ban Treaty , or Nuclear Test Ban Treaty is a treaty prohibiting all test detonations of nuclear weapons...

 on 5 August 1963 along with the United States and the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 which effectively restricted it to underground nuclear tests by outlawing testing in the atmosphere, underwater, or in outer space. The UK signed the Comprehensive Test Ban Treaty
Comprehensive Test Ban Treaty
The Comprehensive Nuclear-Test-Ban Treaty bans all nuclear explosions in all environments, for military or civilian purposes. It was adopted by the United Nations General Assembly on 10 September 1996 but it has not entered into force.-Status:...

 on 24 September 1996 and ratified it on 6 April 1998, having passed the necessary legislation on 18 March 1998 as the Nuclear Explosions (Prohibition and Inspections) Act 1998.

Warning systems



The UK has relied on the Ballistic Missile Early Warning System
Ballistic Missile Early Warning System
The United States Air Force Ballistic Missile Early Warning System was the first operational ballistic missile detection radar. The original system was built in 1959 and could provide long-range warning of a ballistic missile attack over the polar region of the Northern Hemisphere. They also...

 (BMEWS) and, in later years, Defense Support Program
Defense Support Program
The Defense Support Program is a program of the U.S. Air Force that operates the reconnaissance satellites which form the principal component of the Satellite Early Warning System currently used by the United States....

 (DSP) satellites for warning of a nuclear attack. Both of these systems are owned and controlled by the United States, although the UK has joint control over UK based systems. One of the four component radars for the BMEWS is based at RAF Fylingdales
RAF Fylingdales
RAF Fylingdales is a Royal Air Force station on Snod Hill in the North York Moors, England. Its motto is "Vigilamus" . It is a radar base and part of the United States-controlled Ballistic Missile Early Warning System...

 in North Yorkshire
North Yorkshire
North Yorkshire is a non-metropolitan or shire county located in the Yorkshire and the Humber region of England, and a ceremonial county primarily in that region but partly in North East England. Created in 1974 by the Local Government Act 1972 it covers an area of , making it the largest...

.

In 2003 the UK government stated that it will consent to a request from the US to upgrade the radar at Fylingdales for use in the US National Missile Defense
National Missile Defense
National missile defense is a generic term for a type of missile defense intended to shield an entire country against incoming missiles, such as intercontinental ballistic missile or other ballistic missiles. Interception might be by anti-ballistic missiles or directed-energy weapons such as lasers...

 system.

Nevertheless, missile defence is not currently a significant political issue within the UK. The ballistic missile threat is perceived to be less severe, and consequently less of a priority, than other threats to its security.

Attack scenarios


During the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

, a significant effort by government and academia was made to assess the effects of a nuclear attack on the UK. A major government exercise, Square Leg
Square Leg
Square Leg was a 1980 British government home defence exercise that assessed the effects of a Soviet nuclear attack. It was assumed that 131 nuclear weapons would fall on Britain with a total yield of 205 megatons...

, was held in September 1980 and involved around 130 warheads with a total yield of 200 MtonTNT. This is probably the largest attack that the apparatus of the nation state could survive in some limited form. Observers have speculated that an actual exchange would be much larger with one academic describing a 200-megaton attack as an "extremely low figure and one which we find very difficult to take seriously". In the early 1980s it was thought an attack causing almost complete loss of life could be achieved with the use of less than 15% of the total nuclear yield available to the Soviets.

Civil defence



During the cold war, various governments developed civil defence programmes aimed to prepare civilian and local government infrastructure for a nuclear strike on the UK. A series of seven Civil Defence Bulletin films were produced in 1964; and in the 1980s the most famous such programme was probably the series of booklets and public information film
Public information film
Public Information Films are a series of government commissioned short films, shown during television advertising breaks in the UK. The US equivalent is the Public Service Announcement .-Subjects:...

s entitled Protect and Survive
Protect and Survive
Protect and Survive was a public information series on civil defence produced by the British government during the late 1970s and early 1980s. It was intended to inform British citizens on how to protect themselves during a nuclear attack, and consisted of a mixture of pamphlets, radio broadcasts,...

.
The booklet contained information on building a nuclear refuge
Fallout shelter
A fallout shelter is an enclosed space specially designed to protect occupants from radioactive debris or fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War....

 within a so-called 'fall out room' at home, sanitation, limiting fire hazards and descriptions of the audio signals for attack warning, fallout warning and all clear. It was anticipated that families might need to stay within the fall-out room for up to fourteen days after an attack almost without leaving it at all.

The government also prepared a recorded announcement which was to have been broadcast by the BBC if a nuclear attack ever did occur.

Sirens left over from the London Blitz during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

were also to be used to warn the public. The system was mostly dismantled in 1993.

Weapons programmes


See also History of nuclear weapons
History of nuclear weapons
The history of nuclear weapons chronicles the development of nuclear weapons. Nuclear weapons possess enormous destructive potential derived from nuclear fission or nuclear fusion reactions...



Tube Alloys and Manhattan Project


The United Kingdom's nuclear weapons had their genesis in the Second World War when two recently exiled atomic scientists, Otto Frisch
Otto Robert Frisch
Otto Robert Frisch , Austrian-British physicist. With his collaborator Rudolf Peierls he designed the first theoretical mechanism for the detonation of an atomic bomb in 1940.- Overview :...

 and Rudolf Peierls
Rudolf Peierls
Sir Rudolf Ernst Peierls, CBE was a German-born British physicist. Rudolf Peierls had a major role in Britain's nuclear program, but he also had a role in many modern sciences...

 wrote a memorandum on the construction of "a radioactive super-bomb". Forwarded to the Ministry of Aircraft Production (MAP), the secret MAUD Committee
MAUD Committee
The MAUD Committee was the beginning of the British atomic bomb project, before the United Kingdom joined forces with the United States in the Manhattan Project.-Frisch & Peierls:...

 to evaluate the possibilities was soon set up. British scientists worked initially alone on the atomic bomb under the cover name of Tube Alloys
Tube Alloys
Tube Alloys was the code-name for the British nuclear weapon directorate during World War II, when the development of nuclear weapons was kept at such a high level of secrecy that it had to be referred to by code even in the highest circles of government...

, later becoming a partner in the tri-national Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...

 under the Quebec Agreement
Quebec Agreement
The Quebec Agreement is an Anglo-Canadian-American document outlining the terms of nuclear nonproliferation between the United Kingdom and the United States, and signed by Winston Churchill and Franklin Delano Roosevelt on August 19, 1943, two years before the end of World War II, in Quebec City,...

. The Manhattan Project resulted in the two nuclear weapons dropped over Japan
Atomic bombings of Hiroshima and Nagasaki
During the final stages of World War II in 1945, the United States conducted two atomic bombings against the cities of Hiroshima and Nagasaki in Japan, the first on August 6, 1945, and the second on August 9, 1945. These two events are the only use of nuclear weapons in war to date.For six months...

.

Post-war development programme


The United Kingdom started independently developing nuclear weapons again shortly after the war. Labour
Labour Party (UK)
The Labour Party is a centre-left democratic socialist party in the United Kingdom. It surpassed the Liberal Party in general elections during the early 1920s, forming minority governments under Ramsay MacDonald in 1924 and 1929-1931. The party was in a wartime coalition from 1940 to 1945, after...

 Prime Minister
Prime minister
A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime...

 Clement Attlee
Clement Attlee
Clement Richard Attlee, 1st Earl Attlee, KG, OM, CH, PC, FRS was a British Labour politician who served as the Prime Minister of the United Kingdom from 1945 to 1951, and as the Leader of the Labour Party from 1935 to 1955...

 set up a cabinet sub-committee
United Kingdom cabinet committee
The executive arm of the United Kingdom government is controlled by the Cabinet, a group of senior government ministers chaired by the Prime Minister. The Cabinet has a group of committees called cabinet committees, which perform most of the day-to-day work of cabinet government.The committee...

, the Gen 75 Committee (GEN.75)
Gen 75 Committee
The Gen 75 Committee was a subcommittee of the British Cabinet, convened by Prime Minister Clement Attlee on 29 August 1945. The purpose of the committee was to discuss and establish the British government's nuclear policy...

 (known informally as the "Atomic Bomb Committee"), to examine the feasibility as early as 29 August 1945. It was US refusal to continue nuclear cooperation with the UK after World War II (due to the McMahon Act of 1946 restricting foreign access to US nuclear technology) which eventually prompted the building of a bomb:
The committee, under pressure from Hugh Dalton
Hugh Dalton
Edward Hugh John Neale Dalton, Baron Dalton PC was a British Labour Party politician who served as Chancellor of the Exchequer from 1945 to 1947, when he was implicated in a political scandal involving budget leaks....

 and Sir Stafford Cripps
Stafford Cripps
Sir Richard Stafford Cripps was a British Labour politician of the first half of the 20th century. During World War II he served in a number of positions in the wartime coalition, including Ambassador to the Soviet Union and Minister of Aircraft Production...

 to opt out of building the bomb due to its cost, eventually decided to go ahead not just because of considerations of Britain's prestige but also because of the likely industrial importance of atomic energy.

A nuclear programme started in 1946 under the control of the Atomic Energy Research Establishment
Atomic Energy Research Establishment
The Atomic Energy Research Establishment near Harwell, Oxfordshire, was the main centre for atomic energy research and development in the United Kingdom from the 1940s to the 1990s.-Founding:...

 (incorporated into the United Kingdom Atomic Energy Authority
United Kingdom Atomic Energy Authority
The United Kingdom Atomic Energy Authority is a UK government research organisation responsible for the development of nuclear fusion power. It is an executive non-departmental public body of the Department for Business, Innovation and Skills and was formerly chaired by Lady Barbara Judge CBE...

 (UKAEA) in 1954), that was civilian in character, but was also tasked with the job of producing the fissile material, initially only plutonium 239, that was expected to be required for a military programme. It was based on a former airfield, Harwell
Harwell, Oxfordshire
Harwell is a village and civil parish in the Vale of White Horse west of Didcot. It was part of Berkshire until the 1974 boundary changes transferred it to Oxfordshire.-Amenities:...

, Berkshire
Berkshire
Berkshire is a historic county in the South of England. It is also often referred to as the Royal County of Berkshire because of the presence of the royal residence of Windsor Castle in the county; this usage, which dates to the 19th century at least, was recognised by the Queen in 1957, and...

; and a former Royal Ordnance Factory
Royal Ordnance Factory
Royal Ordnance Factories was the collective name of the UK government's munitions factories in and after World War II. Until privatisation in 1987 they were the responsibility of the Ministry of Supply and later the Ministry of Defence....

, Risley in Cheshire
Cheshire
Cheshire is a ceremonial county in North West England. Cheshire's county town is the city of Chester, although its largest town is Warrington. Other major towns include Widnes, Congleton, Crewe, Ellesmere Port, Runcorn, Macclesfield, Winsford, Northwich, and Wilmslow...

. Risley became the headquarters of the Industrial Division of UKAEA, and there were other sites under its control, notably the Calder Hall reactors at Windscale (later Sellafield
Sellafield
Sellafield is a nuclear reprocessing site, close to the village of Seascale on the coast of the Irish Sea in Cumbria, England. The site is served by Sellafield railway station. Sellafield is an off-shoot from the original nuclear reactor site at Windscale which is currently undergoing...

) used to produce weapons grade Pu-239. The first nuclear pile in the UK, GLEEP
GLEEP
GLEEP, which stood for Graphite Low Energy Experimental Pile, was a long-lived experimental British nuclear reactor. Run for the first time on August 15, 1947, it was the first reactor to operate in Western Europe....

, went critical at Harwell on 15 August 1947. AWRE was established at Aldermaston by the Ministry of Supply
Ministry of Supply
The Ministry of Supply was a department of the UK Government formed in 1939 to co-ordinate the supply of equipment to all three British armed forces, headed by the Minister of Supply. There was, however, a separate ministry responsible for aircraft production and the Admiralty retained...

; later becoming the Weapons Division of the (civilian) UKAEA, before being subsumed into the Ministry of Defence
Ministry of Defence (United Kingdom)
The Ministry of Defence is the United Kingdom government department responsible for implementation of government defence policy and is the headquarters of the British Armed Forces....

 in the 1970s.

William Penney
William George Penney
William George Penney, Baron Penney OM, KBE PhD, DSc, , FRS, FRSE, FIC, Hon FCGI was a British mathematician who was responsible for the development of British nuclear technology, following World War II...

, a physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

 specialising in hydrodynamics was asked in October 1946 to prepare a report on the viability of building a UK weapon. Joining the Manhattan project in 1944, he had been in the observation plane Big Stink
Big Stink
Big Stink was the name of a Boeing B-29 Superfortress bomber that participated in the atomic bomb attack on Nagasaki, Japan on August 9, 1945...

 over Nagasaki, and had also done damage assessment on the ground following Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

's surrender. He had subsequently participated in the American Operation Crossroads
Operation Crossroads
Operation Crossroads was a series of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. It was the first test of a nuclear weapon after the Trinity nuclear test in July 1945...

 test at Bikini Atoll
Bikini Atoll
Bikini Atoll is an atoll, listed as a World Heritage Site, in the Micronesian Islands of the Pacific Ocean, part of Republic of the Marshall Islands....

. As a result of his report, the decision to proceed was formally made on 8 January 1947 at a meeting of the GEN.163 committee of six cabinet members, including Prime Minister
Prime minister
A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime...

 Clement Attlee
Clement Attlee
Clement Richard Attlee, 1st Earl Attlee, KG, OM, CH, PC, FRS was a British Labour politician who served as the Prime Minister of the United Kingdom from 1945 to 1951, and as the Leader of the Labour Party from 1935 to 1955...

 with Penney appointed to take charge of the programme.

The project was hidden under the name High Explosive Research or HER and was based initially at the Ministry of Supply
Ministry of Supply
The Ministry of Supply was a department of the UK Government formed in 1939 to co-ordinate the supply of equipment to all three British armed forces, headed by the Minister of Supply. There was, however, a separate ministry responsible for aircraft production and the Admiralty retained...

's Armament Research and Development Establishment (ARDE) at Fort Halstead
Fort Halstead
Fort Halstead is a research site of Dstl, an Executive Agency of the UK Ministry of Defence. It is situated on the crest of the Kentish North Downs, overlooking the town of Sevenoaks...

 in Kent, but in 1950 moved to a new site at AWRE Aldermaston
Atomic Weapons Establishment
The Atomic Weapons Establishment is responsible for the design, manufacture and support of warheads for the United Kingdom's nuclear deterrent. AWE plc is responsible for the day-to-day operations of AWE...

 in Berkshire
Berkshire
Berkshire is a historic county in the South of England. It is also often referred to as the Royal County of Berkshire because of the presence of the royal residence of Windsor Castle in the county; this usage, which dates to the 19th century at least, was recognised by the Queen in 1957, and...

. A particular problem was the McMahon Act. Although British scientists knew the areas of the Manhattan Project in which they had worked well, they only had the sketchiest details of those parts which they were not directly involved in. With the start of the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 there had been some warming of nuclear relations between the UK and US governments, which led to hopes of American cooperation. However these were quickly dashed by the arrest in early 1950 of Klaus Fuchs
Klaus Fuchs
Klaus Emil Julius Fuchs was a German theoretical physicist and atomic spy who in 1950 was convicted of supplying information from the American, British and Canadian atomic bomb research to the USSR during and shortly after World War II...

, a Soviet spy
SPY
SPY is a three-letter acronym that may refer to:* SPY , ticker symbol for Standard & Poor's Depositary Receipts* SPY , a satirical monthly, trademarked all-caps* SPY , airport code for San Pédro, Côte d'Ivoire...

 working at Harwell. Plutonium production reactors were based at Windscale, later known as Sellafield
Sellafield
Sellafield is a nuclear reprocessing site, close to the village of Seascale on the coast of the Irish Sea in Cumbria, England. The site is served by Sellafield railway station. Sellafield is an off-shoot from the original nuclear reactor site at Windscale which is currently undergoing...

 in Cumberland and construction began in September 1947, leading to the first plutonium metal ready in March 1952.

First test and early systems






The first UK weapon test, Operation Hurricane
Operation Hurricane
Operation Hurricane was the test of the first British atomic device on 3 October 1952. A plutonium implosion device was detonated in the lagoon between the Montebello Islands, Western Australia....

, was detonated below the frigate HMS Plym
HMS Plym (K271)
HMS Plym was a River class frigate that served in the Royal Navy between 1943 and 1952.-Construction:Plym was built to the Royal Navy's specifications as a Group II River class frigate...

 anchored in the Monte Bello Islands on 3 October 1952. This led to the first deployed weapon, the Blue Danube
Blue Danube (nuclear weapon)
Blue Danube was the first operational British nuclear weapon. It also went by a variety of other names, including Smallboy, the Mk.1 Atom Bomb, Special Bomb and OR.1001, a reference to the Operational Requirement it was built to fill...

 free-fall bomb, in November 1953. It was very similar to the American Mark 4 weapon in having a 60 inches (152.4 cm) diameter, 32 lens implosion system with a levitated core suspended within a natural uranium tamper. The warhead was contained within a bomb casing measuring 62 inches (1.6 m) diameter and 24 feet (7.3 m) long, and being so large, could only be carried by the V-Bomber fleet.

A nuclear landmine dubbed Brown Bunny, later Blue Bunny, and finally Blue Peacock
Blue Peacock
Blue Peacock, renamed from Blue Bunny and originally dubbed Brown Bunny, was the codename of a British tactical nuclear weapon project in the 1950s—dubbed the chicken-powered nuclear bomb by the press....

 that used the Blue Danube warhead was developed from 1954 with the goal of deployment in the Rhine area of Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

. The system would have been set to an eight-day timer in the case of invasion of Western Europe by the Soviets but was cancelled in February 1958 with only two built. It was judged that the risks posed by the nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...

 and the political aspects of preparing for destruction and contamination of allied territory were simply too high to justify. A more usual reason for cancellation revealed by numerous archived declassified documents was that the Army felt it was too unwieldy and diverted their efforts into a successor, Violet Vision, based on the smaller successor to Blue Danube, Red Beard. None were ever built, the Army instead receiving US ADMs or Atomic Demolition Munitions
Atomic demolition munitions
Atomic demolition munitions , colloquially known as nuclear land mines, are small nuclear explosive devices. ADMs were developed for both military and civilian purposes. As weapons, they were designed to be exploded in the forward battle area, in order to block or channel enemy forces. ...

 under the established procedures for supply of NATO allies from US stocks held in US custody in Europe. A sea mine based on the Blue Danube warhead and codenamed Cudgel was also envisaged for delivery by midget submarines, referred to by naval sources as "sneak craft"; perhaps reflecting a belief that these craft were really rather ungentlemanly methods of waging war. None were built.

A gaseous diffusion plant was built at Capenhurst
Capenhurst
Capenhurst is a village and civil parish in the unitary authority of Cheshire West and Chester and the ceremonial county of Cheshire, England and located on the Wirral Peninsula to the south west of the town of Ellesmere Port...

, near Chester
Chester
Chester is a city in Cheshire, England. Lying on the River Dee, close to the border with Wales, it is home to 77,040 inhabitants, and is the largest and most populous settlement of the wider unitary authority area of Cheshire West and Chester, which had a population of 328,100 according to the...

 and started production in 1953 producing low enriched uranium (LEU). By 1957 it was capable of annually producing 125 kg of highly enriched uranium (HEU). The capacity was further increased and by 1959 it may have been producing as much as 1600 kg per year. At the end of 1961, having produced between 3.8 and 4.9 tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...

s of HEU it was switched over to LEU production for civil use. Additional plutonium production was provided by eight electricity generating Magnox
Magnox
Magnox is a now obsolete type of nuclear power reactor which was designed and is still in use in the United Kingdom, and was exported to other countries, both as a power plant, and, when operated accordingly, as a producer of plutonium for nuclear weapons...

 reactors at Calder Hall and Chapelcross which started operating in 1956 and 1959 respectively.

Thermonuclear weaponry



The detonation by both the US and the Soviet Union of thermonuclear devices alarmed the UK government of Winston Churchill
Winston Churchill
Sir Winston Leonard Spencer-Churchill, was a predominantly Conservative British politician and statesman known for his leadership of the United Kingdom during the Second World War. He is widely regarded as one of the greatest wartime leaders of the century and served as Prime Minister twice...

 and a decision was made on 27 July 1954 to begin development of a thermonuclear bomb, making use of the more powerful nuclear fusion
Nuclear fusion
Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. This is usually accompanied by the release or absorption of large quantities of energy...

 reaction rather than nuclear fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...

. There was little or no dissent in the House of Commons.

The Economist
The Economist
The Economist is an English-language weekly news and international affairs publication owned by The Economist Newspaper Ltd. and edited in offices in the City of Westminster, London, England. Continuous publication began under founder James Wilson in September 1843...

, the New Statesman
New Statesman
New Statesman is a British centre-left political and cultural magazine published weekly in London. Founded in 1913, and connected with leading members of the Fabian Society, the magazine reached a circulation peak in the late 1960s....

 and many left-wing newspapers supported the government's policy of nuclear deterrence as a means of reducing the size of conventional forces. Their view (in 1954-55) is fairly summarised as being not opposed to nuclear deterrence and nuclear weapons, but in their view that of the United States would suffice, and that of the costs of the 'nuclear umbrella' was best left to be borne by the United States alone. Their attitudes to nuclear weapons have changed somewhat since then.

The first prototype, Short Granite, was detonated on 15 May 1957 in Operation Grapple
Operation Grapple
Operation Grapple, and operations Grapple X, Grapple Y and Grapple Z, were the names of British nuclear tests of the hydrogen bomb. They were held 1956—1958 at Malden Island and Christmas Island in the central Pacific Ocean. Nine nuclear detonations took place during the trials, resulting in...

, with disappointing results at 300 ktonTNT, when the target requirement was 1 MtonTNT. A further test of Purple Granite yielded less at 200 ktonTNT. Further testing in 1958 got performance up to the requirement, but none were ever deployed, because the 1958 US-UK Mutual Defence Agreement
1958 US-UK Mutual Defence Agreement
The 1958 US–UK Mutual Defence Agreement is a bilateral treaty between the United States and the United Kingdom on nuclear weapons cooperation.It was signed after the UK successfully tested its first hydrogen bomb during Operation Grapple. While the U.S...

 intervened, making fully developed and Service engineered designs available more quickly, and more cheaply. The first of these was the US Mk-28 weapon
B28 nuclear bomb
The B28, originally Mark 28, was a thermonuclear bomb carried by U.S. tactical fighter bombers and bomber aircraft. From 1962 to 1972 under the NATO nuclear weapons sharing program, American B28s also equipped six Europe-based Canadian CF-104 squadrons known as the RCAF Nuclear Strike Force...

 which was anglicised and manufactured in the UK as Red Snow
Red Snow
Red Snow was a British thermonuclear weapon. Its physics package was apparently similar, if not identical, to that of the United States W28 nuclear warhead used in the B28 nuclear bomb and AGM-28 Hound Dog missile, with an explosive yield of approximately 1.1 megaton.The Red Snow warhead was...

 and quickly deployed as Yellow Sun
Yellow Sun
Yellow Sun was the first British operational high-yield strategic nuclear weapon. The name actually refers only to the outer casing; the warhead was known as "Green Grass" and "Red Snow"...

 Mk.2 in the V-bomber fleet. Red Snow became the warhead of choice for the Blue Steel
Blue Steel missile
The Avro Blue Steel was a British air-launched, rocket-propelled nuclear stand-off missile, built to arm the V bomber force. It was the primary British nuclear deterrent weapon until the Royal Navy started operating Polaris missile armed nuclear submarines....

 stand-off missile and some of the Skybolt missiles intended for carriage by the V-bombers. Under the 1958 US-UK Mutual Defence Agreement
1958 US-UK Mutual Defence Agreement
The 1958 US–UK Mutual Defence Agreement is a bilateral treaty between the United States and the United Kingdom on nuclear weapons cooperation.It was signed after the UK successfully tested its first hydrogen bomb during Operation Grapple. While the U.S...

 5.4 tonnes of UK produced plutonium was sent to the US in return for 6.7 kg of tritium
Tritium
Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...

 and 7.5 tonnes of HEU over the period 1960-1979, replacing Capenhurst production, although much of the HEU was used not for weapons, but as fuel for the growing UK fleet of nuclear submarines, both of the Polaris variety and others numbering approx twelve.

Fifty-eight Blue Danube bombs were produced, although archived declassified files indicate that only a small proportion of these were ever serviceable at any one time. It remained in service until 1963, when it was replaced by Red Beard
Red Beard (nuclear weapon)
Red Beard was the first British tactical nuclear weapon. It was carried by the English Electric Canberra and the V bombers of the Royal Air Force, and by the Blackburn Buccaneers, Sea Vixens and Supermarine Scimitars of the Royal Navy's Fleet Air Arm...

, a smaller tactical boosted fission weapon
Boosted fission weapon
A boosted fission weapon usually refers to a type of nuclear bomb that uses a small amount of fusion fuel to increase the rate, and thus yield, of a fission reaction. The neutrons released by the fusion reactions add to the neutrons released in the fission, as well as inducing the fission reactions...

 that used the same fissile core as Blue Danube and was deployed on many smaller aircraft than the V-bombers, both ashore and at sea aboard five carriers. Stocks of Red Beard were maintained in Cyprus
Cyprus
Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...

, Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

, and a smaller number in the UK.

After the detonation of US and Soviet thermonuclear weapons the UK deployed an Interim Megaton Weapon in the V-bomber fleet until a true thermonuclear weapon could be devised from the Christmas Island tests. This never tested interim weapon derived from the Orange Herald
Orange Herald
- Technical :Orange Herald was a fusion boosted British fission nuclear weapon, comprising a U-235 primary surrounded by lithium deuteride. 'Herald' was suitable for mounting on a missile, utilizing 117 kg of U-235...

 warhead tested at Christmas Island on 31 May 1957 yielding 720 ktonTNT known as Green Grass was merely a very large unboosted pure fission weapon yielding 400 ktonTNT. It was the largest pure fission weapon ever deployed by any nuclear state. Green Grass was deployed first in a modified Blue Danube casing and known as Violet Club
Violet Club
Violet Club was a nuclear weapon deployed by the United Kingdom during the cold war. It was Britain's first operational "high yield" weapon, and was intended to provide an emergency capability until a thermonuclear weapon could be developed from the 1956-1958 Operation Grapple thermonuclear tests...

. A later variant was deployed in a Yellow Sun
Yellow Sun
Yellow Sun was the first British operational high-yield strategic nuclear weapon. The name actually refers only to the outer casing; the warhead was known as "Green Grass" and "Red Snow"...

 Mk.1 casing. A true thermonuclear device was planned for the later Yellow Sun
Yellow Sun
Yellow Sun was the first British operational high-yield strategic nuclear weapon. The name actually refers only to the outer casing; the warhead was known as "Green Grass" and "Red Snow"...

 Mk.2 bomb, and after the 1958 US-UK Mutual Defence Agreement
1958 US-UK Mutual Defence Agreement
The 1958 US–UK Mutual Defence Agreement is a bilateral treaty between the United States and the United Kingdom on nuclear weapons cooperation.It was signed after the UK successfully tested its first hydrogen bomb during Operation Grapple. While the U.S...

 the choice fell on a US Mk.28 warhead manufactured in the UK and known as Red Snow
Red Snow
Red Snow was a British thermonuclear weapon. Its physics package was apparently similar, if not identical, to that of the United States W28 nuclear warhead used in the B28 nuclear bomb and AGM-28 Hound Dog missile, with an explosive yield of approximately 1.1 megaton.The Red Snow warhead was...

. This Red Snow warhead was also fitted in the Blue Steel
Blue Steel missile
The Avro Blue Steel was a British air-launched, rocket-propelled nuclear stand-off missile, built to arm the V bomber force. It was the primary British nuclear deterrent weapon until the Royal Navy started operating Polaris missile armed nuclear submarines....

, an air-launched stand-off missile which remained in service until Dec 1970. It was to have been replaced by Skybolt air-launched ballistic missiles purchased from the United States. In 1962 and 1960 respectively the UK cancelled their Blue Steel extended range upgrade (Blue Steel Mk2)and Blue Streak
Blue Streak missile
The Blue Streak missile was a British medium range ballistic missile . The Operational Requirement for the missile was issued in 1955 and the design was complete by 1957...

 missile projects. It was asserted in Parliament at the time that the Blue Streak missiles were cancelled because of their vulnerability to Soviet attack as they were liquid fuelled an immobile, although this vulnerability was in fact negligible. However, the main aim in British policy had changed from one of independence to interdependence- subsequently the Macmillan Government favoured the purchase of Skybolt missiles from the United States to the continuation of an independent project. Similarly, reassessments of Soviet capabilities changed military perceptions and led to the removal of Thor IRBM missiles in the UK
Project Emily
Project Emily was the deployment of American-built PGM-17 Thor Intermediate-range ballistic missiles in the United Kingdom between 1959 and 1963....

; and Jupiter IRBMs in Italy and Turkey; although the Turkish sites were implicated in an alleged deal following the Cuban Missile Crisis
Cuban Missile Crisis
The Cuban Missile Crisis was a confrontation among the Soviet Union, Cuba and the United States in October 1962, during the Cold War...

. To consternation, and considerable protests, the incoming Kennedy administration cancelled Skybolt at the end of 1962 because it was believed by the US Secretary of State for Defense
United States Secretary of Defense
The Secretary of Defense is the head and chief executive officer of the Department of Defense of the United States of America. This position corresponds to what is generally known as a Defense Minister in other countries...

, Robert McNamara
Robert McNamara
Robert Strange McNamara was an American business executive and the eighth Secretary of Defense, serving under Presidents John F. Kennedy and Lyndon B. Johnson from 1961 to 1968, during which time he played a large role in escalating the United States involvement in the Vietnam War...

, that other delivery systems were progressing better than expected, and a further expensive system was surplus to US requirements.


Polaris


After the cancellation of Skybolt, the UK purchased Polaris missiles for use in UK-built ballistic missile submarines. The agreement between US President John F. Kennedy
John F. Kennedy
John Fitzgerald "Jack" Kennedy , often referred to by his initials JFK, was the 35th President of the United States, serving from 1961 until his assassination in 1963....

 and Prime Minister of the United Kingdom
Prime Minister of the United Kingdom
The Prime Minister of the United Kingdom of Great Britain and Northern Ireland is the Head of Her Majesty's Government in the United Kingdom. The Prime Minister and Cabinet are collectively accountable for their policies and actions to the Sovereign, to Parliament, to their political party and...

 Harold Macmillan
Harold Macmillan
Maurice Harold Macmillan, 1st Earl of Stockton, OM, PC was Conservative Prime Minister of the United Kingdom from 10 January 1957 to 18 October 1963....

, the Polaris Sales Agreement
Polaris Sales Agreement
The Polaris Sales Agreement was an agreement between the United States and the United Kingdom which formally arranged for the Polaris missile system to be provided to the UK to maintain its independent nuclear deterrent. The arrangement had been set up in principle as a result of the Nassau Agreement...

, was announced on 21 December 1962 and HMS Resolution made her first Polaris-armed operational patrol on 15 June 1968. In the 1970s the UK Polaris RVs and warheads were vulnerable to the Soviet ABM
Anti-ballistic missile
An anti-ballistic missile is a missile designed to counter ballistic missiles .A ballistic missile is used to deliver nuclear, chemical, biological or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" describes any antimissile system designed to counter...

 screen concentrated around Moscow, and the UK developed a Polaris improved-front-end (IFE) codenamed Chevaline
Chevaline
Chevaline was a system to improve the penetrability of the British Polaris missile warheads. Devised as an answer to the improved Soviet defences around Moscow, the system was intended to increase the probability that at least one warhead would penetrate the city's anti-ballistic missile defences,...

, designed to counter this ABM defence which threatened to completely nullify an independent UK deterrent posture. When Chevaline became public knowledge in 1980, it generated huge controversy as it had been kept secret by the four governments of Wilson, Heath, Wilson (again) and Callaghan, whilst costs rocketed; admittedly during a period of high inflation; until disclosed by the Thatcher government
Margaret Thatcher
Margaret Hilda Thatcher, Baroness Thatcher, was Prime Minister of the United Kingdom from 1979 to 1990...

. By the time it entered service in 1982 it had cost approx £1bn. The final Polaris/Chevaline patrol took place in 1996, two years after the first Trident-carrying submarine sailed on its first patrol.

As well as the establishment at Aldermaston, the UK nuclear weapons programme also has a factory at Burghfield
Burghfield
Burghfield is a village and civil parish in West Berkshire, England, close to the boundary with Reading.-Location:Burghfield is about southwest of Reading...

 nearby which assembled the weapons and is responsible for their maintenance, and had another in Cardiff
Cardiff
Cardiff is the capital, largest city and most populous county of Wales and the 10th largest city in the United Kingdom. The city is Wales' chief commercial centre, the base for most national cultural and sporting institutions, the Welsh national media, and the seat of the National Assembly for...

 which fabricated non-fissile components and a 2000 acre (8 km²) test range at Foulness
Foulness
Foulness is an island on the east coast of Essex in England, which is separated from the mainland by narrow creeks. The large island had a usually resident population of 212 people in the 2001 census, who live in the settlements of Churchend and Courtsend, at the north end of Foulness. The island...

. Since 1993 the sites have been managed by private consortia. The Foulness and Cardiff facilities closed in October 1996 and February 1997 respectively.

Trident






The UK currently has four Vanguard class
Vanguard class submarine
The Vanguard class are the Royal Navy's current nuclear ballistic missile submarines , each armed with up to 16 Trident II Submarine-launched ballistic missiles...

 submarines based at HMNB Clyde
HMNB Clyde
Her Majesty's Naval Base Clyde is one of three operating bases in the United Kingdom for the Royal Navy...

 in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

, armed with nuclear-tipped Trident missile
Trident missile
The Trident missile is a submarine-launched ballistic missile equipped with multiple independently-targetable reentry vehicles . The Fleet Ballistic Missile is armed with nuclear warheads and is launched from nuclear-powered ballistic missile submarines . Trident missiles are carried by fourteen...

s. The principle of operation is based on maintaining deterrent effect by always having at least one submarine at sea, and was designed for the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 period. One submarine is normally undergoing maintenance and the remaining two in port or on training exercises. It has been suggested that the UK's ballistic missile submarine patrols are coordinated with those of the French
France and weapons of mass destruction
France is known to have an arsenal of weapons of mass destruction. France is one of the five "Nuclear Weapons States" under the Nuclear Non-Proliferation Treaty; but is not known to possess or develop any chemical or biological weapons. France was the fourth country to test an independently...

.

Each submarine carries 16 Trident II D-5 missiles, which can each carry up to twelve warheads. However, the UK government announced in 1998 that each submarine would carry only 48 warheads, an increase of 50% over the 32 warheads carried by Trident's predecessor, Chevaline, (halving the limit specified by the previous government), which is an average of three per missile. However one or two missiles per submarine are probably armed with fewer warheads for "sub-strategic" use causing others to be armed with more; but this is speculative.

The UK-designed warheads are thought to be selectable between 0.3, 5-10 and 100 kt (1.3, 21–42 and 420 TJ); the yields obtained using either the unboosted primary, the boosted primary, or the entire "physics package"; although it must be stressed that these yields and similar data are entirely speculative. The true position is unlikely to be known with certainty for many years; as was the case with the misplaced speculation about the earlier Chevaline programme; only now becoming publicly known. Although the UK designed, manufactured and owns the warheads, there is evidence that the warhead design is similar to, or even based on, the US W76
W76
The W76 is a United States thermonuclear warhead. It was manufactured from 1978-1987, and is still in service .The W-76 is carried inside a Mk-4 re-entry vehicle. U.S...

 warhead fitted in some US Navy Trident missiles, with design data being supplied by the United States through the 1958 US-UK Mutual Defence Agreement
1958 US-UK Mutual Defence Agreement
The 1958 US–UK Mutual Defence Agreement is a bilateral treaty between the United States and the United Kingdom on nuclear weapons cooperation.It was signed after the UK successfully tested its first hydrogen bomb during Operation Grapple. While the U.S...

. The United Kingdom owns 58 missiles which are shared in a joint pool with the United States government and these are exchanged when requiring maintenance with missiles from the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

's own pool and vice versa.

Until August 1998, the UK also retained the WE.177
WE.177
WE.177 was the last air-delivered tactical nuclear weapon of the British Armed Forces. There were three versions; WE.177A was a boosted fission weapon, while WE.177B and WE.177C were thermonuclear weapons...

 nuclear weapon manufactured in the mid-1960s to late 1970s, in air-dropped free-fall bomb and depth charge
Depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...

 versions. This left the four Vanguard class submarines, which replaced the Polaris ones in the early 1990s, as the United Kingdom's only nuclear weapons platform. It has been estimated by the Bulletin of the Atomic Scientists
Bulletin of the Atomic Scientists
The Bulletin of the Atomic Scientists is a nontechnical online magazine that covers global security and public policy issues, especially related to the dangers posed by nuclear and other weapons of mass destruction...

 that the United Kingdom has built around 1,200 warheads since the first Hurricane
Operation Hurricane
Operation Hurricane was the test of the first British atomic device on 3 October 1952. A plutonium implosion device was detonated in the lagoon between the Montebello Islands, Western Australia....

 device of 1952. In terms of number of warheads, the UK arsenal was at its maximum size of about 350 in the 1970s, but this figure does not include the large numbers of US-owned warheads, bombs, nuclear depth bombs supplied from US stocks in Europe for use by NATO allies. At its peak, these numbered 327 for the British Army of the Rhine
British Army of the Rhine
There have been two formations named British Army of the Rhine . Both were originally occupation forces in Germany, one after the First World War, and the other after the Second World War.-1919–1929:...

 in Germany alone.

Replacement for Trident


A decision on the replacement of Trident was made on 4 December 2006. Tony Blair
Tony Blair
Anthony Charles Lynton Blair is a former British Labour Party politician who served as the Prime Minister of the United Kingdom from 2 May 1997 to 27 June 2007. He was the Member of Parliament for Sedgefield from 1983 to 2007 and Leader of the Labour Party from 1994 to 2007...

 (Prime Minister
Prime minister
A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime...

 at that time) told MPs it would be "unwise and dangerous" for the UK to give up its nuclear weapons. He outlined plans to spend up to £20bn on a new generation of submarines for Trident missiles.

He said submarine numbers may be cut from four to three, while the number of nuclear warheads would be cut by 20% to 160. Mr Blair said although the Cold War had ended, the UK needed nuclear weapons, as no-one could be sure another nuclear threat would not emerge in the future.

Deployment of US tactical nuclear weapons



Until 1992 UK forces also deployed US tactical nuclear weapons as part of a US-UK dual-key NATO nuclear sharing
Nuclear sharing
Nuclear sharing is a concept in NATO's policy of nuclear deterrence, which involves member countries without nuclear weapons of their own in the planning for the use of nuclear weapons by NATO, and in particular provides for the armed forces of these countries to be involved in delivering these...

 role. This arrangement commenced in 1958 as Project E
Project E
Project E was a joint project between the United States and the United Kingdom during the cold war to provide nuclear weapons to the British Royal Air Force prior to Britain's own nuclear weapons becoming available...

 to provide nuclear weapons to the RAF prior to a sufficient number of Britain's own nuclear weapons becoming available.

The weapons deployed included nuclear artillery
Nuclear artillery
Nuclear artillery is a subset of limited-yield tactical nuclear weapons, in particular those weapons that are launched from the ground at battlefield targets...

, nuclear demolition mines and warheads for Corporal and Lance missiles in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

; theatre nuclear weapons on RAF
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

 aircraft; Mark 101
Mk-101 Lulu NDB (Nuclear Depth Bomb)
The Mark 101 Lulu was an air-dropped nuclear depth bomb developed by the United States in the 1950s. It utilized a W34 nuclear warhead, with a yield of about 11 kilotons. It was deployed by the United States Navy for the purposes of anti-submarine warfare, in five different models, from 1958 until...

 nuclear depth bomb
Nuclear Depth Bomb
A Nuclear Depth Bomb is the nuclear equivalent of the conventional depth charge and can be used in Anti-Submarine Warfare for attacking submerged submarines...

s on RAF Shackleton
Avro Shackleton
The Avro Shackleton was a British long-range maritime patrol aircraft for use by the Royal Air Force. It was developed by Avro from the Avro Lincoln bomber with a new fuselage...

 maritime patrol aircraft, later replaced by a modern successor, the B-57
B57 nuclear bomb
The B57 nuclear bomb was a tactical nuclear weapon developed by the United States during the Cold War.Entering production in 1963 as the Mk 57, the bomb was designed to be dropped from high-speed tactical aircraft. It had a streamlined casing to withstand supersonic flight. It was 3 m long, with a...

 deployed on RAF Nimrod aircraft.

The Lance missiles were purchased in 1975, to replace Honest John missiles which had been bought in 1960; and were themselves a replacement for the US Corporal missiles deployed in Germany by the Royal Artillery
Royal Artillery
The Royal Regiment of Artillery, commonly referred to as the Royal Artillery , is the artillery arm of the British Army. Despite its name, it comprises a number of regiments.-History:...

. Not generally recognised is the fact that the Royal Artillery deployed a numerically greater quantity of US nuclear weapons than the RAF and Royal Navy combined, peaking at 277 in 1976-78; with a further 50 ADMs deployed with another British Army
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...

 unit, the Royal Engineers
Royal Engineers
The Corps of Royal Engineers, usually just called the Royal Engineers , and commonly known as the Sappers, is one of the corps of the British Army....

, peaking in 1971-81. The dual-key agreement for controlling US tactical nuclear weapons, known as the Heidelberg Agreement, was made on 30 August 1961. The UK sponsored access for the Canadian Army Honest John missile deployments to the US/UK nuclear warhead storage sites.

The UK continues to permit the US to deploy nuclear weapons from its territory, the first having arrived in 1954. During the 1980s nuclear armed USAF Ground Launched Cruise Missile
Ground Launched Cruise Missile
The Ground Launched Cruise Missile, or GLCM, was a ground-launched cruise missile developed by the United States Air Force in the last decade of the Cold War.-Overview:...

s were deployed at RAF Greenham Common
RAF Greenham Common
RAF Station Greenham Common is a former military airfield in Berkshire, England. The airfield is located approximately south-southwest of Thatcham; about west of London....

 and RAF Molesworth
RAF Molesworth
RAF Molesworth is a Royal Air Force station located near Molesworth, Cambridgeshire, United Kingdom with a history dating back to 1917.Its runway and flight line facilities were closed in 1973 and demolished to support ground-launched cruise missile operations in the early 1980s...

. As of 2005 it is believed that approximately 110 tactical B61 nuclear bomb
B61 nuclear bomb
The B61 nuclear bomb is the primary thermonuclear weapon in the U.S. Enduring Stockpile following the end of the Cold War. It is an intermediate yield strategic and tactical nuclear weapon featuring a two-stage radiation implosion design....

s are stored at RAF Lakenheath
RAF Lakenheath
RAF Lakenheath, is a Royal Air Force military airbase near Lakenheath in Suffolk, England. Although an RAF station, it hosts United States Air Force units and personnel...

 for deployment by USAF F-15E Strike Eagle
F-15E Strike Eagle
The McDonnell Douglas F-15E Strike Eagle is an all-weather multirole fighter, derived from the McDonnell Douglas F-15 Eagle. The F-15E was designed in the 1980s for long-range, high speed interdiction without relying on escort or electronic warfare aircraft. United States Air Force F-15E Strike...

 aircraft.

Atomic Weapons Establishment, Aldermaston


The Atomic Weapons Establishment (AWE), Aldermaston (formerly the Atomic Weapons Research Establishment, Aldermaston) is situated just 7 miles (11 km) north of Basingstoke
Basingstoke
Basingstoke is a town in northeast Hampshire, in south central England. It lies across a valley at the source of the River Loddon. It is southwest of London, northeast of Southampton, southwest of Reading and northeast of the county town, Winchester. In 2008 it had an estimated population of...

 and approximately 14 miles (22.5 km) south-west of Reading, Berkshire
Reading, Berkshire
Reading is a large town and unitary authority area in England. It is located in the Thames Valley at the confluence of the River Thames and River Kennet, and on both the Great Western Main Line railway and the M4 motorway, some west of London....

, near a village called Aldermaston
Aldermaston
Aldermaston is a rural village, civil parish and electoral ward in Berkshire, South-East England. In the 2001 United Kingdom Census, the parish had a population of 927. The village is on the southern edge of the River Kennet flood plain, near the Hampshire county boundary...

, bordering with Tadley
Tadley
Tadley is a town and civil parish in the English county of Hampshire.During the 1950s and 1960s, the Atomic Weapons Research Establishment , now known as AWE, became the area's largest employer, and a large number of houses were built during this period to accommodate AWRE workers...

. It was built in 1949 on the site of a former World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

 base and converted to nuclear weapons research, design and development in the 1950s. Although some early test devices were probably assembled on this site, final assembly of Service-engineered weapons takes place at the nearby site of Burghfield.

Royal Ordnance Factories, Cardiff and Burghfield


Other nuclear weapons sites could be found in Cardiff
Cardiff
Cardiff is the capital, largest city and most populous county of Wales and the 10th largest city in the United Kingdom. The city is Wales' chief commercial centre, the base for most national cultural and sporting institutions, the Welsh national media, and the seat of the National Assembly for...

 and Burghfield
Burghfield
Burghfield is a village and civil parish in West Berkshire, England, close to the boundary with Reading.-Location:Burghfield is about southwest of Reading...

 near Reading, Berkshire
Reading, Berkshire
Reading is a large town and unitary authority area in England. It is located in the Thames Valley at the confluence of the River Thames and River Kennet, and on both the Great Western Main Line railway and the M4 motorway, some west of London....

. These were the only two Royal Ordnance Factories (ROFs) not privatised
Privatization
Privatization is the incidence or process of transferring ownership of a business, enterprise, agency or public service from the public sector to the private sector or to private non-profit organizations...

 in the 1980s.

ROF Cardiff, which closed in 1997, was involved in nuclear weapons programmes since 1961. The site was used for the task of recycling old nuclear weapons and precisely shaping uranium 235 (U235) and metallic beryllium
Beryllium
Beryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...

 components for the boosted fission devices used as primaries or 'triggers' in modern thermonuclear weapons. ROF Burghfield was a former Filling Factory
Filling Factories
A Filling Factory was a munitions factory which specialised in filling various munitions, such as bombs, shells, cartridges, pyrotechnics, screening smokes, etc...

, opened in 1942, and run as an Agency Factory, by Imperial Tobacco
Imperial Tobacco
Imperial Tobacco is a global tobacco company headquartered in Bristol, United Kingdom. It is the world’s fourth-largest cigarette company measured by market share , and the world's largest producer of cigars, fine-cut tobacco and tobacco papers...

, to fill Oerlikon 20 mm
Oerlikon 20 mm cannon
The Oerlikon 20 mm cannon is a series of autocannons, based on an original design by Reinhold Becker of Germany, very early in World War I, and widely produced by Oerlikon Contraves and others...

 ammunition.

Anti-nuclear movement



The anti-nuclear movement in the United Kingdom consists of groups who oppose nuclear technologies such as nuclear power
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...

 and nuclear weapons. Many different groups and individuals have been involved in anti-nuclear demonstrations and protests
Anti-nuclear protests
Anti-nuclear protests first emerged in the late 1950s and early 1960s. In the United Kingdom, the first Aldermaston March, organised by the Campaign for Nuclear Disarmament, took place in 1958. In 1961, at the height of the Cold War, about 50,000 women brought together by Women Strike for Peace...

 over the years.

One of the most prominent anti-nuclear groups in the UK is the Campaign for Nuclear Disarmament
Campaign for Nuclear Disarmament
The Campaign for Nuclear Disarmament is an anti-nuclear organisation that advocates unilateral nuclear disarmament by the United Kingdom, international nuclear disarmament and tighter international arms regulation through agreements such as the Nuclear Non-Proliferation Treaty...

 (CND). CND's Aldermaston Marches began in 1958 and continued into the late 1960s when tens of thousands of people took part in the four-day marches. One significant anti-nuclear mobilization in the 1980s was the Greenham Common Women's Peace Camp
Greenham Common Women's Peace Camp
Greenham Common Women's Peace Camp was a peace camp established to protest at nuclear weapons being sited at RAF Greenham Common in Berkshire, England. The camp began in September 1981 after a Welsh group, Women for Life on Earth, arrived at Greenham to protest against the decision of the British...

. In London, in October 1983, more than 300,000 people assembled in Hyde Park as part of the largest protest against nuclear weapons in British history. In 2005 in Britain, there were many protests about the government's proposal to replace the aging Trident weapons system
UK Trident programme
The UK Trident programme is the United Kingdom's Trident missile-based nuclear weapons programme. Under the programme, the Royal Navy operates 58 nuclear-armed Trident II D-5 submarine-launched ballistic missiles and around 200 nuclear warheads on 4 Vanguard-class ballistic missile submarines from...

 with a newer model.

Nuclear posture


UK nuclear posture during the cold war was informed by interdependence with the United States. Operational control of the UK Polaris force was assigned to SACLANT, while targeting policy for its missiles was determined, as for the V-bomber force before it, by NATO's SACEUR, while maintaining an independent wholly UK targeting policy for some circumstances when a critical national emergency required it to be used alone, without the UK's NATO allies. In these circumstances, the 'Moscow criterion' referred to the ability of the UK to strike back at the highly centralised Soviet decision-making apparatus concentrated in the Moscow area, intended to destroy the ability of the Soviet leadership to remain in control of a Soviet Union otherwise untouched. The early beginnings of studies to increase the likelihood of successful penetration of the Polaris warheads to Moscow can be traced back to 1964, before the Polaris system was deployed, in order to preserve this capability in the face of anti-ballistic missile batteries around Moscow. These studies later materialised as Chevaline.

The UK has relaxed its nuclear posture since the collapse of the Soviet Union. The Labour
Labour Party (UK)
The Labour Party is a centre-left democratic socialist party in the United Kingdom. It surpassed the Liberal Party in general elections during the early 1920s, forming minority governments under Ramsay MacDonald in 1924 and 1929-1931. The party was in a wartime coalition from 1940 to 1945, after...

 government's 1998 Strategic Defence Review
Strategic Defence Review
The Strategic Defence Review was a British policy document produced by the Labour Government that came to power in 1997. Then Secretary of State for Defence, George Robertson, set out the initial defence policy of the new government, with a series of key decisions designed to enhance the United...

 made a number of reductions from the plans announced by the previous Conservative
Conservative Party (UK)
The Conservative Party, formally the Conservative and Unionist Party, is a centre-right political party in the United Kingdom that adheres to the philosophies of conservatism and British unionism. It is the largest political party in the UK, and is currently the largest single party in the House...

 government:
  • The stockpile of "operationally available warheads" was reduced from 300 to "less than 200"
  • The final batch of missile bodies would not be purchased, limiting the fleet to 58.
  • A submarine's load of warheads were reduced from 96 to 48. This reduced the explosive power of the warheads on a Vanguard class Trident submarine to "one third less than a Polaris submarine armed with Chevaline." However 48 warheads per Trident submarine represents a 50% increase on the 32 warheads per submarine of Chevaline. Total explosive power has been in decline for decades as the accuracy of missiles has improved, therefore requiring less power to destroy each target. Trident can destroy 48 targets per submarine, as opposed to 32 targets that could be destroyed by Chevaline.
  • Submarines missiles would not be targeted, but rather at several days "notice to fire".
  • Although one submarine would always be on patrol it will operate on a "reduced day-to-day alert state". A major factor in maintaining a constant patrol is to avoid "misunderstanding or escalation if a Trident submarine were to sail during a period of crisis."


Current UK posture as outlined in the Strategic Defence Review of 1998 is as it has been for many years. Only the delivery methods have changed. Trident SLBMs still provide the long-range strategic element as they have done for some years. Until 1998 the free-fall WE.177A, WE.177B and WE.177C bombs provided an aircraft-delivered sub-strategic option in addition to their designed function of tactical battlefield weapons. With the retirement of WE.177, a sub-strategic warhead is stated by Ministers to be incorporated into some (but not all) Trident missiles deployed. The exact mix of weapons on each submarine is unknown as is the numbers and warhead yield. Current UK thinking is that the capacity to launch a very limited strike is a more credible deterrent in the current world situation than use of a MIRVed strategic system.

Nuclear weapons control


The precise details of how a British Prime Minister would authorise a nuclear strike remain secret, although the principles of the Trident control system is believed to be based on the plan set up for Polaris in 1968, which has now been declassified. A closed-circuit television system was set up between 10 Downing Street and the Polaris Control Officer at the Northwood Headquarters
Northwood Headquarters
Northwood Headquarters is a military headquarters facility of the British Armed Forces in Eastbury, Hertfordshire, England, adjacent to the London suburb of Northwood...

 of the Royal Navy. Both the Prime Minister and the Polaris Control Officer would be able to see each other on their monitors when the command was given. If the link failed – for instance during a nuclear attack or when the PM was away from Downing Street – the Prime Minister would send an authentication code which could be verified at Northwood. The Commander in Chief would then broadcast a firing order to the Polaris submarines via the Very Low Frequency radio station at Rugby. The UK has not deployed control equipment requiring codes to be sent before weapons can be used, such as the U.S. Permissive Action Link
Permissive Action Link
A Permissive Action Link is a security device for nuclear weapons. Its purpose is to prevent unauthorized arming or detonation of the nuclear weapon.The United States Department of Defense definition is:...

, which if installed would preclude the possibility that military officers could launch British nuclear weapons without authorisation.


Until 1998, when it was withdrawn from service, the WE.177 bomb was armed with a standard tubular pin tumbler lock
Tubular pin tumbler lock
A tubular pin tumbler lock, also known as Ace lock; axial pin tumbler lock; or radial lock, is a variety of pin tumbler lock in which 6-8 pins are arranged in a circular pattern, and the corresponding key is tubular or cylindrical in shape....

 (as used on bicycle locks) and a standard allen key was used to set yield and burst height. Currently, British Trident commanders are able to launch their missiles without authorisation, whereas their American colleagues cannot. At the end of the Cold War the U.S. Fail Safe Commission recommended installing devices to prevent rogue commanders persuading their crews to launch unauthorised nuclear attacks. This was endorsed by the Nuclear Posture Review and Trident Coded Control Devices were fitted to all U.S. SSBNs by 1997. These devices prevented an attack until a launch code had been sent by the Chiefs of Staff on behalf of the President. The UK took a decision not to install Trident CCDs or their equivalent on the grounds that an aggressor might be able to wipe out the British chain of command before a launch order had been sent.

In December 2008 BBC Radio 4 made a programme titled The Human Button, providing new information on the manner in which the United Kingdom could launch its nuclear weapons, particularly relating to safeguards against a rogue launch. Former Chief of the Defence Staff
Chief of the Defence Staff (United Kingdom)
The Chief of the Defence Staff is the professional head of the British Armed Forces, a senior official within the Ministry of Defence, and the most senior uniformed military adviser to the Secretary of State for Defence and the Prime Minister...

 (most senior officer of all British armed forces
British Armed Forces
The British Armed Forces are the armed forces of the United Kingdom of Great Britain and Northern Ireland.Also known as Her Majesty's Armed Forces and sometimes legally the Armed Forces of the Crown, the British Armed Forces encompasses three professional uniformed services, the Royal Navy, the...

) and Chief of the General Staff
Chief of the General Staff (United Kingdom)
Chief of the General Staff has been the title of the professional head of the British Army since 1964. The CGS is a member of both the Chiefs of Staff Committee and the Army Board...

 (most senior officer in the British Army
British Army
The British Army is the land warfare branch of Her Majesty's Armed Forces in the United Kingdom. It came into being with the unification of the Kingdom of England and Scotland into the Kingdom of Great Britain in 1707. The new British Army incorporated Regiments that had already existed in England...

), General Lord Guthrie of Craigiebank
Charles Guthrie, Baron Guthrie of Craigiebank
General Charles Ronald Llewelyn Guthrie, Baron Guthrie of Craigiebank, was Chief of the Defence Staff between 1997 and 2001 and Chief of the General Staff, the professional head of the British Army, between 1994 and 1997.-Army career:...

, explained that the highest level of safeguard was against a prime minister
Prime minister
A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime...

 ordering a launch without due cause: Lord Guthrie stated that the constitutional structure of the United Kingdom provided some protection against such an occurrence, as while the Prime Minister is the chief executive and so practically commands the armed services, the ultimate commander-in-chief is the Monarch
British monarchy
The monarchy of the United Kingdom is the constitutional monarchy of the United Kingdom and its overseas territories. The present monarch, Queen Elizabeth II, has reigned since 6 February 1952. She and her immediate family undertake various official, ceremonial and representational duties...

, to whom the chief of the defence staff could appeal:
"the chief of the defence staff, if he really did think the prime minister had gone mad, would make quite sure that that order was not obeyed... You have to remember that actually prime ministers give direction, they tell the chief of the defence staff what they want, but it's not prime ministers who actually tell a sailor to press a button in the middle of the Atlantic. The armed forces are loyal, and we live in a democracy, but actually their ultimate authority is the Queen."

The same interview pointed out that while the Prime Minister would have the constitutional authority to fire the Chief of the Defence Staff, he could not appoint a replacement as the position is appointed by the monarch. During the Cold War the Prime Minister was also required to name a senior member of the cabinet as his/her designated-survivor, who would have the authority to order a nuclear response in the event of an attack incapacitating the Prime Minister, and this system was re-adopted after the 9/11 terrorist attacks on the United States.

The programme also addressed the workings of the system; detailing that two persons are required
Two-man rule
The two-man rule is a control mechanism designed to achieve a high level of security for especially critical material or operations. Under this rule all access and actions requires the presence of two authorized people at all times.-Nuclear weapons:...

 to authenticate each stage of the process before launching, with the submarine captain only able to access the firing trigger after two safes have been opened with keys held by the ship's executive and weapons engineering officers. It was explained that all prime ministers issue hand-written orders, termed the letters of last resort
Letters of last resort
The letters of last resort are four identically-worded, hand written letters written by the Prime Minister of the United Kingdom to the four captains of the four British ballistic missile submarines...

, seen by their eyes only, sealed and stored within the safes of each of the four Royal Navy trident submarines: These notes instruct the captain of what action to take in the event of the United Kingdom being attacked with nuclear weapons that destroy Her Majesty's Government in the United Kingdom and/or the chain of command. Although the final orders of the Prime Minister are at his or her discretion, and no fixed options exist, four known options are often presented to prime ministers by military advisers when writing such notes of last resort: (i) Captain ordered to respond to the nuclear attack on the UK by launching submarine's nuclear weapons; (ii) Captain ordered not to respond with nuclear weapons; (iii) Captain ordered to use own judgement whether to return fire with nuclear weapons; (iv) Captain ordered to place himself and ship under the command of Her Majesty's Government in Australia
Government of Australia
The Commonwealth of Australia is a federal constitutional monarchy under a parliamentary democracy. The Commonwealth of Australia was formed in 1901 as a result of an agreement among six self-governing British colonies, which became the six states...

, or alternatively of the President of the United States
President of the United States
The President of the United States of America is the head of state and head of government of the United States. The president leads the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces....

. This system of issuing notes containing orders in the event of the head of government's death is said to be unique to the United Kingdom (although the concept of written last orders, particularly of a ship's captain, is a naval tradition), with other nuclear powers using different procedures. Such orders are destroyed unopened whenever a prime minister leaves office, so the decision of its use or not by previous prime ministers are known only to them - however, all relevant former prime ministers have supported an "independent nuclear deterrent", as does incumbent David Cameron
David Cameron
David William Donald Cameron is the current Prime Minister of the United Kingdom, First Lord of the Treasury, Minister for the Civil Service and Leader of the Conservative Party. Cameron represents Witney as its Member of Parliament ....

. Only former prime minister Lord Callaghan has given any insight on his orders: Callaghan stated that, although in a situation where nuclear weapon use was required - and thus the whole purpose and value of the weapon as a deterrent had failed - he would have ordered use of nuclear weapons, if needed: ...if we had got to that point, where it was, I felt it was necessary to do it, then I would have done it (used the weapon)...but if I had lived after pressing that button, I could have never forgiven myself.

The process by which a Trident submarine would determine if the British government continues to function includes, amongst other checks, establishing whether BBC Radio 4
BBC Radio 4
BBC Radio 4 is a British domestic radio station, operated and owned by the BBC, that broadcasts a wide variety of spoken-word programmes, including news, drama, comedy, science and history. It replaced the BBC Home Service in 1967. The station controller is currently Gwyneth Williams, and the...

 continues broadcasting.

The special relationship


The 1958 'Agreement For Cooperation on the Uses of Atomic Energy for Mutual Defence Purposes' also known as the 'Mutual Defence Agreement' was renewed in 1994 and again in 2005.

Cost


The current Trident system cost £12.6bn (at 1996 prices) and costs £280m a year to maintain. Options for replacing Trident range from £5bn for the missiles alone to £20-30bn for missiles, submarines and research facilities. At minimum, for the system to continue safely after around 2020, the missiles will need to be replaced.

Legality

See also International Court of Justice advisory opinion on the Legality of the Threat or Use of Nuclear Weapons


The Government of the United Kingdom has announced plans to renew the UK's only nuclear weapons system, the Trident missile system. They have published a white paper
White paper
A white paper is an authoritative report or guide that helps solve a problem. White papers are used to educate readers and help people make decisions, and are often requested and used in politics, policy, business, and technical fields. In commercial use, the term has also come to refer to...

 The Future of the United Kingdom’s Nuclear Deterrent in which they state that the renewal is fully compatible with the United Kingdom's treaty commitments and international law. These arguments are summarised in a question and answer briefing published by UK Permanent Representative to the Conference on Disarmament
Conference on Disarmament
Conference on Disarmament is a forum established by the international community to negotiate multilateral arms control and disarmament agreements...



Against


The white paper The Future of the United Kingdom’s Nuclear Deterrent stands in contrast to two counsel's opinion
Legal opinion
In law, an opinion is usually a written explanation by a judge or group of judges that accompanies an order or ruling in a case, laying out the rationale and legal principles for the ruling....

s. The first, commissioned by Peacerights, was given on 19 December 2005 by Rabinder Singh
Rabinder Singh (barrister)
Sir Rabinder Singh , styled The Hon. Mr Justice Singh, is an English High Court judge of the Queen's Bench Division, formerly a barrister, a founding member of Matrix Chambers and a legal academic.-Early life and education:...

 QC
Queen's Counsel
Queen's Counsel , known as King's Counsel during the reign of a male sovereign, are lawyers appointed by letters patent to be one of Her [or His] Majesty's Counsel learned in the law...

 and Professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...

 Christine Chinkin
Christine Chinkin
Christine Chinkin is a Professor of International Law at the London School of Economics and Political Science and theWilliam W. Cook Global Law Professor at the University of Michigan Law School. She is a member of the four person United Nations Fact Finding Mission on the Gaza Conflict created by...

 of Matrix Chambers. It addressed '...whether Trident or a likely replacement to Trident breaches customary international law
Customary international law
Customary international law are those aspects of international law that derive from custom. Along with general principles of law and treaties, custom is considered by the International Court of Justice, jurists, the United Nations, and its member states to be among the primary sources of...

'

Drawing on the International Court of Justice
International Court of Justice
The International Court of Justice is the primary judicial organ of the United Nations. It is based in the Peace Palace in The Hague, Netherlands...

 (ICJ) opinion, Singh and Chinkin advised that:
The second opinion was commissioned by Greenpeace
Greenpeace
Greenpeace is a non-governmental environmental organization with offices in over forty countries and with an international coordinating body in Amsterdam, The Netherlands...

 and given by Philippe Sands
Philippe Sands
Philippe Sands, QC is a British lawyer at Matrix Chambers, and is Professor of International law at University College London. Sands is notable for writing a book, Lawless World, in which he accused US President George W. Bush and Prime Minister Tony Blair of conspiring to invade Iraq in violation...

 QC
Queen's Counsel
Queen's Counsel , known as King's Counsel during the reign of a male sovereign, are lawyers appointed by letters patent to be one of Her [or His] Majesty's Counsel learned in the law...

 and Helen Law, also of Matrix Chambers
Matrix Chambers
Matrix Chambers is a barristers’ set situated at Gray’s Inn, London. It was founded in April 2000 by 22 barristers from 7 different chambers.Matrix was founded shortly before the implementation of the Human Rights Act in October 2000...

, on 13 November 2006. The opinion addressed
With regards to the jus ad bellum, Sands and Law advised that
The phrase "very survival of the state" is a direct quote from paragraph 97 of the ICJ ruling. With regards to international humanitarian law, they advised that
Finally, with reference to the NPT, Sands and Law advised that

Government defence


At the start of the House of Commons
British House of Commons
The House of Commons is the lower house of the Parliament of the United Kingdom, which also comprises the Sovereign and the House of Lords . Both Commons and Lords meet in the Palace of Westminster. The Commons is a democratically elected body, consisting of 650 members , who are known as Members...

 debate to authorize the replacement of Trident, Margaret Beckett
Margaret Beckett
Margaret Mary Beckett is a British Labour Party politician who has been the Member of Parliament for Derby South since 1983, rising to become the Deputy Leader of the Labour Party under John Smith, from 18 July 1992 to 12 May 1994, and briefly serving as Leader of the Party following Smith's death...

 stated:
The subsequent vote was won overwhelmingly, including unanimous support from the opposition Conservative Party
Conservative Party (UK)
The Conservative Party, formally the Conservative and Unionist Party, is a centre-right political party in the United Kingdom that adheres to the philosophies of conservatism and British unionism. It is the largest political party in the UK, and is currently the largest single party in the House...

.

The Government position remains that it is abiding by the NPT legally in renewing Trident and Britain has the right to possess nuclear weapons, a position reiterated by Tony Blair
Tony Blair
Anthony Charles Lynton Blair is a former British Labour Party politician who served as the Prime Minister of the United Kingdom from 2 May 1997 to 27 June 2007. He was the Member of Parliament for Sedgefield from 1983 to 2007 and Leader of the Labour Party from 1994 to 2007...

 in PMQs on 21 February 2007.

In contrast, the report by Sands was commissioned solely by Greenpeace
Greenpeace
Greenpeace is a non-governmental environmental organization with offices in over forty countries and with an international coordinating body in Amsterdam, The Netherlands...

 and the report by Singh and Chinkin by the Peace Rights group, both notable groups in opposition to renewal, use or proliferation of nuclear weapons.

Furthermore, the British Government and NATO do not recognise advisory opinion of the ICJ, as interpreter of IHL and referred to by Sands et al., (see Advisory Opinion
Advisory opinion
An advisory opinion is an opinion issued by a court that does not have the effect of adjudicating a specific legal case, but merely advises on the constitutionality or interpretation of a law. Some countries have procedures by which the executive or legislative branches may certify important...

) with regard to use of nuclear weaponry as legally binding.

This position is held in common with all five nuclear states as defined in the NPT. However, only the United Kingdom has expressed its opposition to the establishment of a new legally binding treaty to prevent the threat or use of nuclear weapons against non-nuclear states by its vote in the United Nations General Assembly
United Nations General Assembly
For two articles dealing with membership in the General Assembly, see:* General Assembly members* General Assembly observersThe United Nations General Assembly is one of the five principal organs of the United Nations and the only one in which all member nations have equal representation...

 in 1998.

This legal position is further discussed in the article International Court of Justice advisory opinion on the Legality of the Threat or Use of Nuclear Weapons.

See also

  • Anti-nuclear movement in the United Kingdom
    Anti-nuclear movement in the United Kingdom
    The anti-nuclear movement in the United Kingdom consists of groups who oppose nuclear technologies such as nuclear power and nuclear weapons. Many different groups and individuals have been involved in anti-nuclear demonstrations and protests over the years....

  • Global Security Institute
    Global Security Institute
    The Global Security Institute is a international organization with a mission to eliminate nuclear weapons through international cooperation and security. It aims to influence national laws, seeking to accomplish its mission by focusing on nuclear arms control, non-proliferation, and...

  • Letters of last resort
    Letters of last resort
    The letters of last resort are four identically-worded, hand written letters written by the Prime Minister of the United Kingdom to the four captains of the four British ballistic missile submarines...

  • Nuclear disarmament
    Nuclear disarmament
    Nuclear disarmament refers to both the act of reducing or eliminating nuclear weapons and to the end state of a nuclear-free world, in which nuclear weapons are completely eliminated....

  • Nuclear testing
    Nuclear testing
    Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them...

  • The War Game
    The War Game
    The War Game is a 1965 television documentary-style drama depicting the effects of nuclear war on Britain. Written, directed, and produced by Peter Watkins for the BBC's The Wednesday Play anthology series, it caused dismay within the BBC and in government and was withdrawn from television...

     (An earlier, documentary-style, TV film, also dealing with the effects of nuclear attack on the United Kingdom, that was made in 1965 and banned from being broadcast until the mid 1980s)
  • Threads
    Threads
    Threads is a British television drama produced by the BBC in 1984. Written by Barry Hines and directed by Mick Jackson, it is a documentary-style account of a nuclear war and its effects on the city of Sheffield in northern England....

     (A fictional film about the effects of nuclear war on the United Kingdom)
  • United Kingdom and weapons of mass destruction
    United Kingdom and weapons of mass destruction
    The United Kingdom possesses, or has possessed, a variety of weapons of mass destruction, including nuclear, biological, and chemical weapons. The United Kingdom is one of the five official nuclear weapon states under the Nuclear Non-Proliferation Treaty and has an independent nuclear deterrent...


Further reading

  • Arnold, Lorna
    Lorna Arnold
    Lorna Arnold is a historian who has written a number of books connected with the British nuclear weapons programmes.As the second official historian of the British nuclear weapons programmes, she has had access to previously secret documents and personally knew many of the people involved...

     (2001). Britain and the H-Bomb. The official history up to the 1958 US-UK Mutual Defence Agreement. Copyright MoD. Published Palgrave. ISBN 0-312-23518-6 in North America, ISBN 0-333-94742-8 outside North America.
  • Gowing, Margaret
    Margaret Gowing
    Professor Margaret Gowing, CBE, was an English historian.- Overview :Margaret Gowing was involved with the production of several volumes of the officially sponsored History of the Second World War, published by Her Majesty's Stationery Office in conjunction with Longman's, Green and Co...

     and Arnold, Lorna
    Lorna Arnold
    Lorna Arnold is a historian who has written a number of books connected with the British nuclear weapons programmes.As the second official historian of the British nuclear weapons programmes, she has had access to previously secret documents and personally knew many of the people involved...

     (1974). Independence and Deterrence: Britain and Atomic Energy, 1945-1952. Volume 1: Policy Making. London: The Macmillan Press. ISBN 0-333-15781-8.
  • Gowing, Margaret
    Margaret Gowing
    Professor Margaret Gowing, CBE, was an English historian.- Overview :Margaret Gowing was involved with the production of several volumes of the officially sponsored History of the Second World War, published by Her Majesty's Stationery Office in conjunction with Longman's, Green and Co...

     and Arnold, Lorna
    Lorna Arnold
    Lorna Arnold is a historian who has written a number of books connected with the British nuclear weapons programmes.As the second official historian of the British nuclear weapons programmes, she has had access to previously secret documents and personally knew many of the people involved...

     (1974). Independence and Deterrence: Britain and Atomic Energy, 1945-1952. Volume 2: Policy Execution. London: The Macmillan Press. ISBN 0-333-16695-7.
  • Denys Blakeway and Sue Lloyd-Roberts (1985). Fields of Thunder: Testing Britain's Bomb London, Unwin.
  • Wynne, Humphrey (1997). RAF Strategic Nuclear Deterrent Forces, their origins, roles and deployment, 1946-69. The documentary history. Copyright MoD. Published by The Stationery Office. ISBN 0-11-772833-0.
  • Paul Rogers, "Possible Nuclear Attack Scenarios on Britain", Proceedings of the Conference on Nuclear Deterrence, Implications and Policy Options for the 1980s, International Standing Conference on Conflict and Peace Studies, London, 1982.
  • Roy Dommett
    Roy Dommett
    Roy Dommett CBE is a retired engineer and rocket scientist, and formerly the United Kingdom's Chief Missile Scientist, who for many years led the United Kingdom's research and development of both nuclear rockets and space rockets for the delivery of satellites to orbit...

    , "The Blue Streak Weapon". Prospero, refereed journal of the BROHP, Spring 2005.
  • George Hicks and Roy Dommet, "History of the RAE [Farnborough] and Nuclear Weapons". Prospero, refereed journal of the BROHP, Spring 2005.
  • Proceedings of the Royal Aeronautical Society, Symposium on Chevaline 2004, ISBN 1-85768-109-6. See note on sources at Talk:Nuclear weapons and the United Kingdom
  • Dr Peter Jones, Director AWE (Ret), "The Chevaline Technical Programme". Prospero, the refereed journal of the BROHP, Spring 2005.
  • Peter Nailor
    Peter Nailor
    Professor Peter Nailor was a civil servant university teacher, intellectual entrepreneur and raconteur, who served as Professor of Politics at the University of Lancaster, Professor of History at the Royal Naval College, Greenwich, and Provost of Gresham College.-Early life and education:The...

    , The Nassau Connection: the organisation and management of the British POLARIS project, London: H.M.S.O, (1988).
  • Dr Frank Panton, "The Unveiling of Chevaline". Prospero, the refereed journal of the BROHP, Spring 2005.
  • Dr Frank Panton, "Polaris Improvements and the Chevaline Programme". Prospero, the refereed journal of the BROHP, Spring 2004.

External links