British nuclear weapons and the Falklands War

The British government did not seriously consider using its nuclear weapons during the 1982 Falklands War. Britain had ratified the Treaty of Tlatelolco which established a nuclear-weapon-free zone across Latin America in 1969 and made a commitment in the United Nations during 1978 to not use these weapons against non-nuclear powers such as Argentina. The British War Cabinet never contemplated the use of nuclear weapons but Prime Minister Margaret Thatcher may have done so separately when considering options to respond to a potential serious defeat.

Four of the British Royal Navy warships which were sent to the South Atlantic following the invasion of the Falklands initially carried nuclear depth bombs as part of their standard armament. The head of the British military wanted to retain them on the ships in case the Soviet Union became involved in the war but this was opposed by civilian Ministry of Defence staff. The War Cabinet decided on 8 April 1982 to have these weapons removed before the ships departed. It had to reluctantly reverse this decision three days later due to the impracticality of rapidly offloading the depth bombs. On 28 May the War Cabinet decided that the weapons should be returned to the UK and many of them were shipped back before the end of the conflict. The presence of nuclear depth bombs in the naval task force was reported by journalists soon after the end of the war but not confirmed by the British government until 2003.

It has separately been alleged that a British ballistic missile submarine was sent to the South Atlantic to potentially attack Argentina. This has been denied by senior British government figures as well as the commander of the submarine in question. Historians have found no evidence of such a deployment. Nuclear-capable Avro Vulcan bombers were used in the war but were armed only with conventional bombs.

The British nuclear arsenal did not deter Argentina's invasion of the Falklands on 2 April 1982 due to the commitments the British government had made to not use these weapons. The Argentine government was also unconcerned about the deployment of nuclear-capable British forces during the war. Experts have debated the implications of the war on whether nuclear deterrence prevents conflicts.

Falklands War
The Falkland Islands is an archipelago in the South Atlantic Ocean and a British Overseas Territory. There has been a long-running sovereignty dispute over the islands between Argentina and the British government. This dispute escalated in 1982, and on 2 April that year Argentine forces invaded and captured the islands. At this time the islands were defended only by a small party of Royal Marines. The British government decided to liberate the Falklands and very rapidly assembled and dispatched a task force of Royal Navy warships to begin this process.

After initial diplomatic negotiations failed, fighting began on 1 May with British forces launching air attacks on Argentine positions in the Falklands. Further negotiations proved fruitless, and British forces landed on the islands on 21 May. The Argentine forces there were defeated and surrendered on 14 June 1982 following a series of fierce battles. Several Royal Navy warships were sunk by Argentine air attacks during the war.

British nuclear weapons
The United Kingdom first tested a nuclear weapon in 1952 and began producing operational nuclear bombs from 1953. This made the UK the third country to deploy these weapons. During the Cold War the British military was equipped with hundreds of nuclear devices. The size of this force peaked between 1974 and 1981 when the British nuclear arsenal comprised approximately 500 nuclear warheads.

The British Armed Forces operated several types of nuclear weapons in 1982. The Royal Navy's four ballistic missile submarines were equipped with 100 warheads fitted to standard Polaris missiles and 35 fitted to missiles that had been upgraded through the Chevaline programme. The submarines comprised the British strategic nuclear force and were focused on deterring the Soviet Union. The Royal Navy was also assigned 43 WE.177A nuclear depth bombs; these were tactical nuclear weapons intended to be used against submarines. The Royal Air Force had 250 WE.177 bombs. In addition, the British Armed Forces also had access to more than 150 nuclear warheads provided by the United States. Most of the American-owned warheads were assigned to British Army units in Germany.

During the early 1980s many Royal Navy warships routinely carried WE.177A nuclear depth bombs. This practice had begun during the 1960s and was not publicised by the Royal Navy. It was first officially disclosed in the 1981 Defence White Paper. The weapons had an explosive yield of 0.5 ktonTNT and could be dropped from anti-submarine helicopters or Sea Harrier jet fighters.

Pre-war
In 1967 the British government signed the Treaty of Tlatelolco which established a nuclear-weapon-free zone across Latin America and the nearby waters, including the Falkland Islands. The government ratified the treaty in 1969. Argentina also signed the treaty in 1967 but had still not ratified it at the time of the Falklands War. Under the terms of the treaty, the UK was not able to deploy nuclear weapons to the Falkland Islands and its other dependencies in the South Atlantic or their territorial waters. It was legal for the UK to deploy nuclear weapons to other locations in the South Atlantic, including the territorial waters of Argentina. Nuclear powered ships, such as the Royal Navy's nuclear submarines, were outside the scope of the Treaty of Tlatelolco.

Prior to the Falklands War the British government had provided a commitment to not use its nuclear weapons against countries that did not possess these weapons. In June 1978 the British government issued a "Negative Security Assurance" as part of a process overseen by the United Nations' Special Session on Disarmament. In this assurance the government stated that it would not use nuclear weapons against non-nuclear states unless any of these states attacked the "UK, its dependent territories, its armed forces or its allies" in "association or alliance with a nuclear weapons state". Argentina was a non-nuclear state, though as it had not ratified the Treaty on the Non-Proliferation of Nuclear Weapons or the Treaty of Tlatelolco at the time of the Falklands War the British government was not legally obliged to treat it as such.

The Argentine government was aware that it was not protected from British nuclear attack under the terms of the Treaty of Tlatelolco. However, it believed that the UK would not use these weapons in response to an invasion of the Falklands. The national security experts John Arquilla and María Moyano Rasmussen have observed that due to the "normative inhibitions against the threat" of using nuclear weapons "there is no evidence of the [Argentine] junta being intimidated" by the "extremely unlikely possibility" that Britain would use its nuclear arsenal. The Argentine government decided to invade in the belief that the British government was not strongly committed to retaining the Falklands and conventional British forces could not be deployed at such a distance from the UK.

During the war
From the outset of the conflict the British government had no intention of using nuclear weapons. On 27 April Viscount Trenchard, the Minister for Defence Procurement, stated in the House of Lords that "categorically ... there is no question at all of our using nuclear weapons in this dispute". This statement was made to ensure that the British government's position on the matter was clear. An opinion poll conducted in the UK on 14 April 1982 found that 93 per cent of respondents opposed using nuclear weapons against Argentina and 5 per cent supported doing so. A key issue underpinning the government's and public's views was a perception that the use of these extremely powerful weapons would have been grossly disproportionate to the threat Argentina posed to the UK.

The British official historian of the Falklands War, Lawrence Freedman, investigated post-war "suggestions ... that the nuclear option had been seriously considered" as part of preparing the official history during the early 2000s. He found that the possibility of using nuclear weapons may have been included in a very early draft of the options paper prepared for the British government following the Argentine invasion, but this had been removed well before the paper was completed and submitted to ministers. Freedman concluded that "I have found no references to any consideration of nuclear employment. This was never taken seriously as a realistic possibility". This finding is in line with comments made by the Chief of the Defence Staff during the Falklands War, Admiral Sir Terence Lewin, who had told Freedman in 1989 that "there was never any thought whatever of giving advice to the War Cabinet that nuclear weapons should be used. It never entered our remotest thoughts".

During the mid-2010s historians Peter Hennessy and James Jinks also looked into the claims that the British government had been willing to use nuclear weapons against Argentina. While endorsing Freedman's conclusion that the War Cabinet did not consider the use of nuclear weapons, they stated that Prime Minister Margaret Thatcher had probably done so separately. Hennessy and Jinks' source was the former Permanent Secretary of the Ministry of Defence, Sir Michael Quinlan, who had noted in a 2013 BBC interview that Thatcher had told him after the war that she would have considered using nuclear weapons had the British forces faced defeat.

The political scientists Todd S. Sechser and Matthew Fuhrmann considered this issue in 2017. They believe that the British government deliberately deployed nuclear-capable forces to suggest to the Agentines that these weapons could be used, though no preparations to do so occurred. They labelled Quinlan's comments about Thatcher "a stunning revelation".

Deployment
The Royal Navy hurriedly assembled a task force of warships in response to the Argentine invasion of the Falklands. It comprised ships located in the UK as well as ships that were undertaking exercises or operational deployments elsewhere. Emphasis was put on getting the task force to the Falkland Islands as quickly as possible so that it could limit the build-up of Argentine forces on the islands. This led to urgent efforts at the Royal Navy's bases in the UK and Gibraltar to stock the ships with supplies.

Several of the warships that were assigned to this force were carrying nuclear depth bombs at the time. The aircraft carriers HMS Hermes (R12) and HMS Invincible (R05) had 16 and 10 WE.177A nuclear depth bombs respectively, representing the majority of the Royal Navy's holdings of these weapons. The frigates HMS Brilliant (F90) and HMS Broadsword (F88) each carried two WE.177As. Three warships and three Royal Fleet Auxiliary (RFA) support ships carried 'surveillance rounds' or 'training rounds'. The 'surveillance rounds' were inert WE.177As fitted with sensors used to monitor conditions in weapons magazines. The 'training rounds' were also inert versions of the weapons used to practice handling nuclear depth bombs.

It was not feasible to remove the nuclear depth bombs before the warships sailed from Gibraltar and the UK between 1 and 7 April. The main issue which prevented this was the need for the task force be rapidly dispatched. While some of the nuclear depth bombs could have been offloaded from warships at Portsmouth, this could not be done covertly and the unloading process would disrupt work to prepare other ships to deploy given that all major activities needed to cease in a 270 m radius while the weapons were being moved.

Lewin favoured retaining the weapons on board the ships. He did not believe that they would be necessary and had no plans for them to be used, but wanted the ships to retain the weapons in case the Soviet Union intervened in the war and its submarines attacked the British force. Civilian staff in the Ministry of Defence disagreed with Lewin and advocated for urgent actions to remove nuclear weapons from the warships before they sailed. This in turn led to concerns among some senior Royal Navy officers over civilians overriding military assessments. The British War Cabinet debated what to do about the nuclear depth bombs. Thatcher and the ministers who made up the War Cabinet had not previously been aware that British warships routinely carried nuclear weapons. They disagreed with Lewin's views on the desirability of sending nuclear depth bombs to the South Atlantic and preferred that this not occur. The matter was considered at the War Cabinet's first meeting on 7 April. At this time its members wanted to remove the weapons before the warships entered combat as long as this could be done covertly so as to not disclose the whereabouts of British nuclear weapons. If the issue was raised in Parliament, the government would have confirmed that nuclear weapons would not be used but not comment on whether the warships were carrying them. On 8 April the War Cabinet endorsed a proposal made by Foreign Secretary Francis Pym that the nuclear weapons should be removed.

Following the War Cabinet's decision on 8 April consideration was given to options to unload the weapons from the warships at sea. One option involved transferring the active and inert depth bombs stored on board frigates to the aircraft carriers or RFA ships where they would be less vulnerable. Due to a shortage of ships, an RFA vessel wasn't available to return the weapons to the UK at this time. Consideration was also given to offloading the depth bombs at Ascension Island in the South Atlantic when the task force arrived there. This was ruled out largely on the grounds of urgency, as the operation would delay the task force's departure from Ascension by up to 36 hours. The island was also ill-suited as it lacked suitable facilities for storing nuclear weapons or covertly unloading them from warships.

Due to the difficulty of offloading the nuclear depth bombs, the War Cabinet agreed on 11 April that they should be retained on board the task force's ships. This decision was made reluctantly. It was decided that all of the weapons would be stored on board the two aircraft carriers as they had the best protected weapons magazines. Thatcher stressed that the ships carrying nuclear weapons must not come within 3 mi of the Falkland Islands as this could breach the terms of the Treaty of Tlatelolco. The nuclear depth bombs on board Brilliant were transferred to RFA Fort Austin on 16 April. Those on board Broadsword were offloaded four days later to RFA Resource. These weapons were subsequently transferred to the aircraft carriers; Fort Austins weapons were moved to Hermes on 9 May and Resources to Invincible on 14 May. The surveillance and training rounds were also transferred from several destroyers and frigates to RFA ships during mid-May and early June.

Removal
The sinking of several British warships by Argentine aircraft in late May led to concerns over the consequences of a ship carrying nuclear weapons being attacked. The War Cabinet decided on 28 May that the nuclear depth bombs as well as the surveillance and training rounds should be returned to the UK. Due to operational demands this could not be achieved immediately, and an assessment was made of the risks involved with keeping the weapons on board ships that might be attacked. It was concluded that there was no risk of the nuclear depth bombs exploding if the aircraft carriers were struck by Argentine Exocet missiles though it was possible that the ships would become contaminated with nuclear material.

The weapons on board Invincible were transferred to Fort Austin on 2–3 June. Fort Austin returned to the UK on 29 June. Hermes's nuclear depth bombs were offloaded to Resource on 26 June. This ship reached the UK on 20 July. The nuclear depth bombs were sent to storage facilities after the RFA ships returned to the UK.

Seven of the containers holding active and inert nuclear weapons were damaged during transfers between the various ships. None of the weapons was affected and they were all judged to be "safe and serviceable" following inspections after they arrived back in the UK.

Allegations
Shortly after the Argentine invasion of the Falklands the BBC World Service incorrectly reported that the nuclear-armed ballistic missile submarine HMS Resolution (S22) was operating off Argentina. Resolution was conducting a standard 72-day long patrol in the North Atlantic at this time and her commander and navigator were amused when they learned about the story. Family members of Resolution's crew who contacted the navy about the report were assured it was false. In August 1984 the British New Statesman magazine published an article claiming that the British government had considered using one of the Royal Navy's ballistic missile submarines to attack the mainland of Argentina. This article alleged that a Resolution-class submarine had been sent to operate near Ascension Island following the sinking of the destroyer HMS Sheffield (D80) in early May to bring its missiles within range of Argentina. Supposedly, the British government intended to threaten Argentina with nuclear missiles or even make a demonstrative nuclear attack on Córdoba Province if a troop ship or aircraft carrier were sunk. The article stated that its source was the Labour Party member of parliament Tam Dalyell who claimed to have learned this from an unnamed Conservative member of parliament. The Conservative MP was likely the backbencher Alan Clark.

The British government strongly denied these allegations. The First Sea Lord during the Falklands War, Admiral Sir Henry Leach, stated that "we did not contemplate a nuclear attack and did not make any preparatory moves for such action" and that the ballistic missile submarines remained in their usual patrol areas. The claims were raised again in 1989 by the British academic Paul Rogers. In 2005 a psychoanalyst who had regularly met with French President François Mitterrand during the time of the Falklands War claimed that he had told her that Thatcher had threatened to use nuclear missiles against Argentina unless France provided codes to disable Argentina's Exocet missiles.

Historians' assessments
Freedman investigated these claims in the early 2000s and judged that they were not justified. He did not find any archival evidence that indicated that a Resolution-class submarine had been sent to the South Atlantic. Freedman suggested that the conservative MP who told Dalyell about the supposed deployment may have done so as "a mischievous test ... of the latter's gullibility".

The claims that a ballistic missile submarine had been deployed were also explored by Hennessy and Jinks as part of a 2015 history of the Royal Navy's submarine force. They interviewed Resolution's commander at the time of the Falklands War as well as Admiral Sir Peter Herbert who had been the Flag Officer Submarines. Both were adamant that there had been no consideration of sending a ballistic missile submarine to the South Atlantic and that Resolution had completed a standard patrol. Hennessy and Jinks also dismissed the claims made by Mitterrand's psychoanalyst, noting that it is not clear what 'codes' for Exocet missiles she was referring to.

Vulcan bombers
Several of the Royal Air Force's Avro Vulcan bombers were used in the Falklands War. While these aircraft formed a key part of the UK's nuclear deterrent force they operated during the war solely as conventional bombers. Flying from Ascension Island, Vulcans made seven attacks against Argentine forces in the Falklands during Operation Black Buck.

The British government did not consider making preparations for the Vulcans to use nuclear weapons during the Falklands War. However, it was aware that the aircraft were primarily considered nuclear bombers and this was noted as part of a Cabinet discussion on 14 April. The Cabinet also noted the desirability of the Argentine government being concerned that Vulcans would be used to attack the country's mainland, though the British had no intention of doing so. In 2017 Sechser and Fuhrmann suggested that "Britain may have exploited the aircraft's perceived atomic connection to intimidate Argentina".

Aftermath
The deployment of nuclear weapons-capable British forces to the South Atlantic did not cause the Argentine government to believe that the UK would use these weapons during the war. Officials dismissed the wartime speculation over this issue. The Argentine government also considered it highly unlikely that the British would employ nuclear weapons if their forces were defeated in the Falklands.

The Soviet embassy in Argentina encouraged speculation following the sinking of Sheffield that the ship had been carrying nuclear weapons. It was also alleged that the British had raised nuclear depth charges from the wrecks of Sheffield and the destroyer HMS Coventry (D118), with the Soviets helping to spread these claims. While both destroyers had deployed carrying surveillance rounds, they were removed prior to their loss. British divers had operated on the wreck of Coventry, but this was to recover classified equipment. The depth of the ocean where Sheffield sank was beyond the reach of diving equipment.

In November 1982 a collection of letters from a Royal Navy officer who had been killed in the war was published. In these letters he had observed sighting what he took to be a dummy nuclear depth bomb on RFA Fort Austin. This revelation led at least one journalist to later confirm that nuclear depth bombs had been sent to the South Atlantic. The Ministry of Defence did not issue a statement confirming this fact until December 2003, when it did so in response to repeated requests made by a journalist working at The Guardian. President of Argentina Nestor Kirchner requested that the British government "ask our forgiveness" for sending nuclear weapons into the South Atlantic.

Following the Falklands War British ministers considered whether Royal Navy warships should continue to routinely carry nuclear depth bombs. It was reported in 1985 that the government was reluctant to authorise this due to its concerns over the practice. Eric Grove, a naval historian and defence analyst, wrote in 1987 that it had been decided to "keep the stockpile [of nuclear depth bombs] ashore during peacetime". The Royal Navy maintained its practice of not confirming or denying whether individual ships were carrying nuclear weapons; this led to Australian authorities declining permission for Invincible to be repaired in an Australian dry dock during 1983. In contrast, defence commentator and historian Norman Polmar stated in 2007 that Royal Navy ships continued to carry nuclear depth bombs until the weapons were retired in 1993.

During the 1980s the governments of Argentina and Brazil repeatedly claimed that the UK had stationed nuclear weapons in the Falkland Islands following the war. The British government denied these allegations and stated it had no intentions of deploying nuclear weapons to the military facilities that had been constructed in the islands. The British also provided an assurance that they would continue to abide by the Treaty of Tlatelolco.

Commentary on nuclear deterrence
Experts have discussed the implications of the non-use of nuclear weapons in the Falklands War. In 1988 the American political scientist John Mueller observed that the Argentine government felt confident to challenge the UK as it believed that the British would not escalate the conflict through the use of nuclear weapons. Royal United Services Institute fellow Jeremy Stocker similarly wrote in 2007 that such weapons "will not deter lesser adventurism where the use of nuclear weapons would be disproportionate and so not credible as a deterrent – for example, the 1982 Falklands War". In 2017 Sechser and Fuhrmann gave the Falklands conflict as an example of a nuclear-armed country failing to coerce a nation with a weaker military.

The conflict has also been cited as part of broader debates over whether nuclear weapons have the capacity to deter wars. The American philosopher Douglas P. Lackey wrote in 1984 that "British nuclear threats did not prevent seizure of the Falkland Islands" as part of a section of a book in which he asserted that nuclear weapons made no difference to the outcomes of international crises and wars. In 1989 the British international relations expert Evan Luard reached a similar conclusion. He noted that while international relations theories held that the ability of nuclear weapons to deter conflict was greatest when one country had them and the other did not, the Falklands War was one of several examples that demonstrated that this was not actually the case. Further, Luard concluded that if the British government had sought to deter the war by threatening Argentina with nuclear weapons it would have been counter-productive as the threat would have not been credible given the severe reputational costs associated with making a nuclear first strike. In 2008 the American researcher Ward Wilson argued that the Falklands War was one of a number of conflicts that demonstrated that nuclear weapons do not deter wars. Derrin Culp, who is also an American researcher, authored an article in 2012 critiquing that by Wilson. As part of this, he argued that nuclear deterrence did not fail during the Falklands War as the British government had never indicated that it would use these weapons in response to an invasion of the islands.