Washington D.C., July 16, 2021 - The United Kingdom in the 1970s and 1980s aspired to improve its nuclear weapons capability to bomb Soviet targets, including major cities, without having to depend on the United States, according to documents obtained and posted today by the National Security Archive. British officials had a variety of motives for seeking advanced modern submarine-launched ballistic missiles, from retaining their status as a nuclear power, to uncertainty about American reliability down the road, to a desire to stay ahead of their continental rivals the French, the records show.
U.S. officials recognized British concerns, but they understood they could reap certain benefits in return for assisting them. Nixon suggested the British could “block for us” in the European Community and his administration as well as Jimmy Carter’s pressed for the “quid” of freer American access to the Indian Ocean island of Diego Garcia, which to this day is a key military outpost.
Today’s posting, based on declassified materials released under the Freedom of Information Act, is the second in a series on the U.S.-U.K. special nuclear relationship, which afforded London access to the advanced technology it needed to stay in the nuclear game. The records delve into internal U.S. deliberations and bilateral communications with the British, providing a more detailed picture of this most significant partnership. Several documents are published here for the first time.
Concern About Future U.S. Reliability Influenced British Quest for Trident Missiles
by William Burr
The recent British decision to increase their nuclear weapons stockpile—the first U.S. ally to do so in years—may involve deploying more Trident II submarine-launched ballistic missiles (SLBMs) that have been central to the United Kingdom’s strategic forces. What made such an option available is that since the 1960s, the United States has provided the British with advanced nuclear technology, first Polaris SLBMs and later Trident II missiles, that supported their determination to remain a nuclear weapons state. The Trident deployments were the consequence of complex research and development efforts and prolonged U.K.-U.S. negotiations during the 1970s and 1980s, but U.S. leaders were supportive because they saw a British nuclear role as a worthwhile element of military cooperation. Yet, the British worried that they might not always be able to rely on U.S. support in a military crisis seeking a capability to strike Soviet Union targets independently, slipping through Soviet anti-ballistic missile defenses. In a document published for the first time today, one of Henry Kissinger’s aides wrote that the British wanted to be able to “assure … penetration of the Moscow ABM complex in an extreme ‘go it alone scenario’.
This is the second of two postings on the “special” U.K.-U.S. nuclear relationship that made British SLBM deployments possible. Part I documented the early years of the nuclear ties, including John F. Kennedy’s decision at the 1962 Nassau Conference to provide British Prime Minister Harold Macmillan with Polaris missiles. Part II, today’s posting, documents subsequent developments, beginning with U.S.-British negotiations during the 1970s when the Nixon administration’s inability to offer an acceptable post-Polaris replacement led the British to develop their own reentry vehicle, with U.S. aid. Nothing came without strings attached and the Nixon administration linked U.S. assistance to expanded access to Diego Garcia, British territory in the Indian Ocean. Negotiations during the Carter and Reagan administrations, however, were more successful and the British won access to U.S. MIRV (multiple independently targetable re-entry vehicles) technology, enabling them to pose a more lethal threat to the Soviet Union. Diego Garcia remained an element of linkage with the British in the Trident negotiations, with Washington seeking greater access to the island.
SLBM technology was a major element in the Anglo-American nuclear relationship during the Cold War but so was exchange of sensitive nuclear information and materials, about which far less has been declassified. Also important was that the United Kingdom provided bases for U.S. nuclear weapons and delivery systems, from Thor Missiles to B-47 bombers and U.S. Polaris submarines and more. The British would have a “joint decision” in the use of any British-based U.S. nuclear weapons, as confirmed by the 1958 Murphy-Dean agreement (see Document 5 in Part I of this series.) During the Euromissile Crisis of the early 1980s, a new issue emerged, the control of U.S. nuclear-armed Ground Launched Cruise Missiles (GLCMs) that would be based in the United Kingdom as part of NATO’s decisions on Theater Nuclear Forces. To placate Parliamentary opponents who wanted “dual key” arrangements for the GLCMs, the Margaret Thatcher government updated Murphy-Dean in 1983 so that the “joint decision” language covered decisions to launch cruise missiles in event of war. Documents on these developments, including the 1983 agreement as released by the British, are published for the first time today.
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The United Kingdom has deployed Vanguard-class submarines with Trident II nuclear-armed submarine-launched ballistic missiles (SLBMs) leased from the United States under arrangements negotiated with the Reagan administration in 1982. This arrangement has a long and complex pre-history stretching back to the Kennedy administration, which agreed to provide Polaris Submarine Launched Ballistic Missiles (SLBMs) to the United Kingdom so that it had an advanced strategic nuclear weapons capability. By the time of the Nixon administration the British were trying to update Polaris SLBMs so that they could infiltrate Soviet ABM defenses in the event of war. The difficulties of negotiations with Washington, however, led the British to develop their own nuclear reentry vehicle, Super Antelope, which Henry Kissinger characterized as “stupid” because he did not understand the technology. Nevertheless, the “special” nuclear relationship continued, and the U.S. supported Super Antelope, although its shelf-life was uncertain. By the late 1970s, however, the British wanted something better, the Trident missile with MIRV (multiple independently targetable re-entry vehicles) technology that would enable them to aim more warheads accurately at Soviet targets, including Moscow its ABM defenses notwithstanding. And the Carter and Reagan administrations were willing to provide MIRVed systems for British nuclear submarines because of the political and logistical advantages of cooperation.
For the British, upgrading their nuclear forces was essential to maintain their “credibility” and a capability to use them independently when “supreme national interests are at stake,” which the United States recognized in the communiqué for the December 1962 Nassau Conference. According to a British Cabinet discussion in March 1982, a strategic nuclear force under “British national control” was “essential” because “no one could foresee what might happen over the next 30-40 years to the North Atlantic Treaty Organisation or to the United States attitude to the defence of Europe.” Moreover, the British did not want France to be the only nuclear-armed power in Western Europe. That the British believed that a nuclear capability was central to remaining an influential power was left unsaid, although Kissinger said it privately to Nixon in 1972: "they’ll be a nothing-country if they’re not in [the nuclear business]."
If the British could not rely on U.S. support during a major crisis with the Soviet Union (or later, Russia), they wanted their own nuclear weapons for a capability to strike Moscow and major urban targets. A public British Defense Ministry document from July 1980 declared that a Trident force was necessary to convince Soviet leaders that, even if the United States held back from a conflict with Moscow, “the British force could still strike a blow so destructive that the penalty for aggression would have proved too high.” The decision to designate Moscow and other major Soviet cities top British targets came to be known as the “Moscow Criterion.” While targeting cities and civilian populations contravenes the Geneva Conventions, the United Kingdom has excluded nuclear weapons from its interpretation of the Conventions’ 1977 Protocol 1.
Today’s posting publishes a variety of declassified U.S. and British records from the 1970s and 1980s documenting the Anglo-American dialogue on post-Polaris strategic submarine systems that eventually led to the 1982 agreement on Trident II. It was a rocky road, however, because what the U.S. was willing to offer in the early 1970s was not what the British believed best suited their interests. While the British expressed interest in acquiring MIRV technology, the Nixon administration was not responsive. It was not until the late 1970s, when the international situation was deteriorating, that the U.S. government became willing to provide MIRVs to London. The declassified record documents these and related issues, including internal British discussions on the need to update the 1958 Murphy-Dean agreement, that would be negotiated by Assistant Secretary of State Lawrence Eagleburger and British Ambassador Oliver Wright.
As noted in Part I of this series, the British continue to keep Vanguard-submarines armed with Trident II up and running. Each submarine, of a force of four, can carry 8 SLBMs and 40 warheads, although more would be possible. To support the force, the British have maintained a nuclear warhead stockpile in the range of 225 units (never officially announced). Although Whitehall committed in 2010 to reduce the stockpile to 180 by the mid-2020s, in March 2021 it dropped that commitment when the Boris Johnson government announced that it would instead raise the nuclear stockpile to 260 owing to the uncertain global environment. The detailed numbers, however, have been kept secret.
The Johnson government’s announcement was a surprise to the international community. It reversed London’s historic policy of supporting reductions in nuclear stockpile numbers, as befitting the U.K.’s role as a sponsor of the NPT, whose Article VI called for progress in nuclear disarmament. For that reason, the implications of the British decision for the next NPT review conference may be damaging. The Biden administration has made no comment on the matter, although it may have been an unwelcome development because it could give ammunition to U.S. supporters of nuclear force expansion while running against President Biden’s inclinations toward cuts. Whether the nuclear issue rose to the agenda of the recent Biden-Johnson conversations has not been disclosed, but no doubt it has been the subject of discussion between U.S. and British officials.
The idea of an Anglo-American “special relationship” has been invoked for decades to convey the especially close cooperation between London and Washington in a variety of areas, not only diplomatic and intelligence and military but especially in the nuclear realm. Yet Boris Johnson dislikes the idea of a “special relationship” because, to him, it conveys a British dependence on the United States. Dependence, however, is an element of the story; for example, the British nuclear deterrent involves the leasing of U.S. Trident II missiles for the submarine force and the provision of U.S. MIRV technology to better improve the odds of penetrating Soviet ABM forces and striking key urban targets in Russia. In any event, the provision of this technology during the Carter and Reagan administrations involved bargaining, with the British making concessions in other areas so that Washington would find advantages to providing expensive and sensitive technology.
The British had been interested in MIRV technology, but it was only one of the possibilities they considered after they began thinking about how to upgrade the Polaris system. But when the British expressed an interest in MIRVed Poseidon SLBMs during 1973, the Nixon administration was not forthcoming because it would have required the White House to take the matter to Congress, with which it had difficult relations even before the Watergate scandal developed. Moreover, transferring MIRV technology to the British would have complicated arms control talks with Moscow. Besides the SALT complications, Kissinger believed that it would be “bad” if the British got MIRVs because it would put them far ahead of the French, thus complicating U.S.-French relations. Thus, the U.S. was only willing to offer the reentry vehicles geared for the new Poseidon SLBM but not in their MIRVed form. Yet, “de-MIRVed” Poseidon was an unproven technology that could have been expensive to develop.
The British opted to pursue R&D for the less expensive home-grown Super Antelope reentry vehicle (latter renamed Chevaline), which would be used to improve Polaris and so enable it to penetrate Soviet ABM defenses around Moscow. With the British having just joined the European Community (EC), this was a safer choice because it would avoid debates over the “special relationship” while allowing possible nuclear collaboration with France. In any event, the U.S. continued the close nuclear relationship by agreeing to assist the British with Super Antelope, including helping to test nuclear devices at the Nevada Test Site.
Later in the 1970s, during the Carter administration, circumstances for transferring the MIRV to the British became more propitious. With U.S.-Soviet relations becoming more difficult, Carter was receptive to the initial proposal made informally by British Prime Minister James Callaghan in early 1979. Reaching agreement on the timing of an announcement, however, was difficult in part because of SALT concerns, but also the need to finalize a NATO agreement on Theater Nuclear Forces (TNF). SALT II proved less of an obstacle because it did not exclude the transfer of delivery systems technology to countries that had previously received it. Moreover, the Soviet invasion of Afghanistan in December 1979 postponed any possibility for ratifying SALT while improving the atmosphere for a decision to provide the British with Trident I, a MIRVed system. The Reagan administration took a step further by offering the British the even more powerful Trident II, which ensured that they were not stuck with an eventually obsolete Trident I, which the United States would eventually abandon.
Both the Carter and the Reagan administrations were strongly committed to the Anglo-American relationship, more for hardheaded than sentimental reasons. According to historian Suzanne Doyle, both U.S. presidents viewed the special relationship in “transactional terms”: they sought to link various foreign and military policy desiderata to the agreements to supply the MIRVed Trident. For example, Jimmy Carter’s Pentagon wanted the British to open further U.S. access to Diego Garcia in the Indian Ocean, a military base, for contingencies in the Middle East and South Asia, while the Reagan administration required the British to slow down their departure from Belize for the sake of stability in the region. Yet, the U.S. wanted the British to get a good price so they would have more resources for conventional forces, which was to the U.S.’s advantage.
Compared to the Nixon years, the internal U.S. record of the decision-making on Trident during the Carter and Reagan administrations is relatively scanty. This is owing mainly to the slowness of underfunded declassification processes at presidential libraries and the National Archives generally. Moreover, with changes in the preservation arrangements for the State Department’s central files during the 1970s, the kind of rich internal record that would show up in those files earlier in the decade is not at all matched by the material consigned to the P-reels later in the decade. Why that is the case is unclear, but perhaps less material was going into the central files compared with the records of offices and bureaus.
For the negotiations on the Trident C-4 and D-5 archival pickings are slim, especially with Presidential Libraries operating under pandemic restrictions. The Carter Library has declassified a few items, with enough available digitally to provide a general sense of the process. Under pandemic conditions, only a few items are presently available from the Reagan Library, although enough to give a perspective on U.S. thinking. Major files from there require further exploration to determine what has been released and what needs to be requested. On the British side, there is a substantial body of declassified material at their National Archives, including the web site of the Margaret Thatcher Foundation. That those records are available is a result of the British twenty-year rule, which ensures that important material (if not everything) on military policy, among other issues, becomes available for research.
Editor’s note: Thanks to Matthew Jones, London School of Economics for helpful comments on this posting and for sharing documents. Also, thanks to Kristan Stoddart, Swansea University, and Oliver Barton, LSE, for sharing valuable material.
I. Super Antelope or Poseidon or MIRVs?
Digital National Security Archive [DNSA]; from U.S. National Archives, Department of State Records, Record Group 59 [RG 59], Subject-Numeric Files, 1970-1973, Top Secret Files, box 25, POL 7 US
Assistant Secretary of State for Politico-Military Affairs Spiers notified Deputy Secretary of State John Irwin about the talks with the British on their plans for the Super Antelope warhead for their Polaris SLBMs. During the Super Antelope project definition phase, U.S. and U.K. officials had met for discussions, with updates of what London would need in the next phase of development. In late July 1972, the British put it in writing: they asked for further U.S. help with Super Antelope so they could test components at the underground nuclear test site in Nevada and conduct flight tests on U.S. ranges, among other requirements. For the underground tests, the British had a schedule in mind, with the first test for late 1973 or early 1974, although the actual date would slip to May 1974. The request went to the White House, which approved it in National Security Decision Memorandum 185 (See Document 4) with Kissinger authorizing up to three tests at the Nevada test site. The tests were to be unpublicized, and the British were to be informed that U.S. cooperation on these tests did “not imply any assurances regarding the successful outcome of the project nor subsequent U. S. cooperation in the Super Antelope missile improvement program.”
DNSA; from The National Archives (United Kingdom), PREM 15/1362
During this period, the Nixon administration had two highly secret nuclear policy issues under discussion with London. One was the U.S. negotiation with the Soviet Union over a Soviet proposal to renounce the use of nuclear weapons, for which Nixon and Kissinger sought British views (codenamed “Hullaballoo”). The Soviet proposal led to the Agreement on the Prevention of Nuclear War (June 1973). The other issue was the ongoing discussions of Super Antelope. On 10 August, after the Hullaballoo talks, Kissinger told Cabinet Secretary Burke Trend and his colleagues that the administration “wished to be as helpful as possible” to help the British meet their strategic objectives, but that depended on the results of the November election and the situation in Congress. Later, British defense official Patrick Nairne met with Atomic Energy Commission Chairman James Schlesinger. For a fuller record, see below (Document 3).
Nixon Presidential Library [NPL], NSC Files, Henry Kissinger Office Files, Box 63, Exchange with the UK-SLBMs
Meeting with Patrick Nairne, AEC Chair James Schlesinger offered several options so that British SLBMs could stay ahead of ABM threats: “complete support” for the development of Super Antelope, sharing designs for either Poseidon or Trident (C-4) re-entry vehicles, or the sale of either Poseidon or Trident SLBMs, with some cost estimates. (Schlesinger’s memorandum, attached, included provision of the Trident “bus” for MIRVs but that was a drafting error.) For example, providing the British with the MK-3 Poseidon RV would provide a “much enhanced capability of penetrating the Soviet ABM defense.” When Schlesinger made that offer he was tacitly excluding the possibility of sharing MIRV technology used on Poseidon SLBMS: his claim was that the British had said they did not need it and there was concern that providing MIRVs would damage the ongoing SALT II negotiations with the Soviets. Instead, the U.S. would provide non-MIRVed Poseidon RVs suitable for a few warheads and decoys. That option, which the British would eventually call “Option M,” would remain on the Kissinger-Schlesinger agenda for months, although they kept it so secret that U.S. technical officials may never have fully evaluated the option.
DNSA; from RG 59, Subject-Numeric 1970-73, Top Secret Files. Box 25. DEF 1 U.K.-U.S.
Spiers informed Deputy Secretary Irwin and Ambassador Johnson of the ongoing discussions on the provision of support for Super Antelope by facilitating the testing of up to three British nuclear devices at the Nevada Test Site, if the British have decided to continue a program to harden the Polaris warhead and missile. The Atomic Energy Commission would make the necessary arrangements.
DNSA; from RG 59, Subject-Numeric Files, 1970-73, Top Secret Files, box 11, POL U.K. Word having reached the State Department about Kissinger’s back-channel discussions with the British, Department officials weighed in on the major options under consideration. Johnson recommended to Kissinger against giving “either an affirmative or a negative decision on the sale of POSEIDON to the UK.” Whether to proceed with Super Antelope or to acquire Poseidon RVs was still being debated in London and the debate needed to run its course. Moreover, Washington needed to “weigh the substantial contribution to our own Balance of Payments position which the sale of POSEIDON would represent against the undesirable effects of the release of this sophisticated weapons technology.” Yet the sale could have adverse implications for the SALT process, e.g., no-transfer concerns. Finally, if the U.S. said “no” it would raise the question whether the U.S. was terminating the “special relationship.” The State Department recommended a “warm, sympathetic but noncommittal response to a Heath request for POSEIDON” as the best way to “advance US interests at this point.”
NPL, NSC Files, Henry Kissinger Office Files, Box 63, Exchange with the UK-SLBMs
Enclosing the U. Alexis Johnson memorandum (see Document 5 above), Helmut Sonnenfeldt found it “wordy but thoughtful,” but that the main point was valid: “to remain in a sympathetic posture, but not to make a commitment,” even to a question about a hypothetical.
NPL, NSC Files, Henry A. Kissinger Office Files, box 62, U.K. MemCons 1973 Jan.-April
Visiting Washington for talks, during a conversation with Nixon, Prime Minister Edward Heath reviewed what he saw as the three options for the post-Polaris SLBM force: hardening of the nose cone, Poseidon missiles with MIRVs, and Super Antelope. Heath or the U.S. notetaker misconstrued what the British were interested in: they were not then looking at a Poseidon MIRV option as Heath suggested, but the de-MIRVed Poseidon “Option M” described earlier. In any event, according to Heath, the British had to decide whether to continue the deterrent “under the present arrangements” or seek a new weapon. Poseidon with MIRVs was a strong British preference. Nixon acknowledged that a “separate” British deterrent was important and that he was “sympathetic” to cooperation with the UK.
A few days later, during a long conversation with Kissinger on U.S-European relations, Nixon suggested that the British could “block for us in the Community,” suggesting that they could work against any policies that hurt U.S. interests. Kissinger agreed further, noting that a Poseidon deal could “keep the British quiet” but also give the U.S. leverage in the negotiations with the Soviets on the prevention of nuclear war treaty. Kissinger added that “it is in our interest to keep the British in the nuclear business” and that Heath “realizes they’ll be a nothing-country if they’re not in it.”
NPL, NSC Files, Henry A. Kissinger Office Files, box 62, U.K. MemCons HAK London Trip, May 1973
This meeting between Kissinger and British Cabinet Secretary Burke Trend, held shortly after former’s “Year of Europe” speech, covered U.S.-EC relations, SLBMs, SALT, and other issues. The “Year of Europe” initiative would lead to testy U.S. relations with London (the British and other EC members did not jump quickly enough to suit Kissinger), but that lay ahead. Trend made it clear that the British wanted to “maintain the technology” needed to develop delivery systems and would be looking to “engage the French somehow.” London had just joined the EC, so relations with France were especially important from that perspective. For Trend, costs of nuclear systems were an important consideration but also worrisome were prospects for Soviet progress in missile defense. Trend’s comments reflected British interest in maintaining a technological base for developing strategic weapons, which could be put at risk if London purchased a U.S. nuclear system.
Kissinger replied that he had no problem with British cooperation with the French because of his belief in “independent deterrents” and that the “nuclear field [was] a way of realistic cooperation.”
During the months before this meeting the British continued to explore their post-Polaris options, including “M” (the de-MIRVed Poseidon) and Super Antelope, but also “Stag” a hybrid of Super Antelope and Poseidon. Reflecting that debate was a memorandum that Trend handed off during the meeting: it raised questions about future developments in Soviet missile defense and in that context the relative worth of the U.S. Mark III RV compared with the British STAG/Super Antelope RV. Much information from the memorandum has been withheld but one theme that comes through is the U.S. belief that a de-MIRVed Poseidon RV would have superior capability to breach Soviet defenses.
NPL, NSC Files, Henry A. Kissinger Office Files, box 63, Exchanges with the U.K.--Nuclear
Odeen and Sonnenfeldt discussed the state of play with the talks with the British and enclosed a response to the questions that the British had raised on 10 May. The ABM Treaty notwithstanding, the Treaty allowed missile defenses for Moscow and that remained a concern to the British. Referring to the British implication that ABMs less capable than U.S. Sprint missiles would be equally effective in striking Poseidon RVs or Super Antelope, Odeen and Sonnenfeld observed that not only was the British assessment “misleading,” it appeared to have been “written to justify a Super Antelope conclusion.” The U.S. response “tries to provide a more balanced view” (although leaning toward higher confidence in Poseidon). They further noted that whether the British went for Poseidon or Super Antelope or another alternative, there would have to be a formal presidential decision, consultations with Congress, an executive agreement, and consultations with Allies and the Soviets..
Odeen and Sonnenfeldt also criticized a Defense Department official for telling the British that the U.S. would never sell Poseidon and that, owing to Watergate, the Defense Department had “full responsibility” for the talks. They advised Kissinger to tell Schlesinger to restore “discipline” to the Defense Department.
NPL, NSC Files, Henry Kissinger Office Files, box 63, Exchange with the UK-SLBMs [1 of 2]
Through Ambassador Cromer, Burke Trend informed Kissinger that the British government was still reviewing its post-Polaris options but would not reach any conclusions until late July. While the British had not seriously considered a full-MIRV option, they now believed it might be viable because in the SALT II talks the U.S. was rejecting any limits on MIRVed SLBMs. While that was incorrect – the problem of limits on MIRVs was unresolved – Trend asked that if a “political obstacle” did not exist, whether President Nixon was “willing to contemplate the possibility of offering fully MIRVed Poseidon.”
James Schlesinger, having served as director of central intelligence for a short and tumultuous stint, was about to become secretary of defense, so Kissinger turned to him for input on British nuclear developments (see Document 11).
NPL, NSC Files, Henry Kissinger Office Files, box 63, Exchanges with the UK- Nuclear
Schlesinger advised Kissinger that MIRVed Poseidon was out of the question. In the SALT talks the U.S. had rejected a ban on MIRVed SLBMs and on the transfer of strategic systems, which would make it difficult to defend a proposal to provide the British with MIRVs. Moreover, critics in and out of the government “regard MIRV as a capability particularly prejudicial to long-term arms control possibilities.” Schlesinger was referring to concern that the proliferation of MIRVs by both the U.S. and the Soviets would create a potentially more unstable situation unless both sides could agree to curb them. Noting that the MIRV issue was unresolved in SALT, Schlesinger believed that “a debate on this subject would now be inimical to the US negotiating position.” Therefore, the British “should only consider the range of upgrade options offered in our past discussions.”
NPL, NSC Files, Henry A. Kissinger Office Files, box 64, Exchanges with the U.K.-Other, July 12, 1973 [1 of 3]
With Watergate casting its shadow over the White House, Cromer met with Kissinger at the Western White House and asked about the MIRV option. Kissinger responded that Schlesinger “does not see why you want it” because MIRVs have a lower yield, if high accuracy, which the British did not need. Responding to Cromer’s statement that the British wanted the “best” – MIRVs – Kissinger later observed that going for MIRVs would “create Congressional and Soviet problems.” While Kissinger left the MIRV option open for the future, he showed a little confusion by saying the U.S. could provide Poseidon “MK III warheads for MIRV retrofit,” but Cromer corrected him by noting that the problem was not the nuclear warheads, “which we have,” but the technology to deliver them. Cromer asked if that—no MIRVs—was the answer to Trend’s recent message and Kissinger responded affirmatively.
A meeting with Trend in late July went over the same ground with the same outcome in the context of Kissinger’s anger over the EC response to his “Year of Europe” initiative. Although one of Kissinger’s staff experts vainly argued for providing the British with MIRVs, Kissinger’s anger about the EC responses to the Year of Europe was governing his approach to Trend’s request. (See Document 14).
NPL, NSC Files, Henry Kissinger Office Files, box 63, Exchange with the UK ‐ SLBMs [1 of 2]
Donald Cotter, Schlesinger’s assistant on nuclear matters, relayed the gist of a meeting with British Defense Ministry official Victor Macklen on MIRVs and Poseidon. Although Cotter was not entirety sure why Macklen had come to Washington—to raise the question of a MIRV option, to clarify confusion over warhead characteristics, or to get more information on the Mk III—during the discussion, Macklen asked if anything had changed on the possibility of a MIRV option; Cotter replied negatively. While leaving open the option for the future, there was a “high probability of congressional, executive, and public debate if we provide MIRV technology at this time.” While Macklen said that the British had no strategic or military need for the MIRV, the Navy was interested for cost and logistical reasons and because it was a “proven system.’
Gerald R. Ford Presidential Library [GRFPL], National Security Adviser, Memoranda of Conversations, box 2 Memoranda of Conversations – Nixon Administration
During a discussion with James Schlesinger a few days later, Kissinger spelled out more of this thinking on the relationship between Poseidon and the Year of Europe. The conversation began with Schlesinger asking Kissinger if he could tell lower-level officials about the proposal for “de-MIRVed Poseidon.” That lower-level officials had not known about it – they had not even reviewed the practically of the proposal – had put them at a disadvantage when speaking with the British.
Kissinger was concerned about leaks but also wanted to know what would be most useful for dragging out the issue. Later, he went right to the point by observing that the broader problem of European unity was the context for his decisions on Poseidon: “We want to keep Europe from developing their unity as a bloc against us.” To do that it was necessary to divide the British and the French: by keeping the latter “hoping they can get ahead of the British.” Thus, if “If we gave the British MIRV while the French were so far behind, it would be bad.” Schlesinger later asked whether the British should be “play[ed] along more?” by suggesting they had a chance to get MIRV.” Kissinger appeared to agree, saying that he had told British Embassy Minister Richard Sykes that ‘‘it was 51-49 with the President inclined to go to bat for it.”
NPL, NSC Files, Henry A. Kissinger Office Files, box 63, Exchange with the US-SLBMs [1 of 2]
After completing deliberations on post-Polaris options, Prime Minister
Heath informed Nixon that his government had decided to go ahead with Super Antelope for its SLBM force. Owing to the economic crisis the government had to reduce spending, including the defense budget, although it had not touched outlays for conventional forces. In that context, the de-MIRVed Poseidon option was too expensive, so Heath claimed, and the British would continue developing Super Antelope. While it might not be able to strike Moscow itself because of ABM defenses, the warhead would be enough to strike targets in the greater Moscow area “and other great cities of the Western USSR.” Heath asked that Nixon “confirm your agreement to the principle of our continuing collaboration” on the “full development of the improved Polaris system.” With this decision, Heath avoided a public debate over the Poseidon option and its implications for relations with the United States and the EC.
GRFPL, National Security Adviser, Memoranda of Conversations, box 3, Memoranda of Conversations – Nixon Administration
Kissinger and Schlesinger briefly discussed Heath’s decision on Super Antelope. Irritated that the Poseidon option had been rejected, Kissinger saw it as an example of a “continuing record of stupidity” and Schlesinger claimed it was “dumb” because Super Antelope was “only a hardened warhead,” statements that overlooked the degree to which it included a sophisticated array of decoys. Moreover, the U.S. would control the warhead’s testing for six years. Yet, even if they wanted London to take the Poseidon option, it would have been an uphill fight because the Nixon Administration would have had to secure congressional approval for even the non-MIRVed Poseidon option, which would have been a difficult task for the White House given Watergate.
Before they discussed Super Antelope, Schlesinger mentioned two other issues involving the British: enriched uranium deliveries to the United Kingdom and the island of Diego Garcia, where the U.S. had developed a small base. That was an issue for talks with London because, consistent with Kissinger’s wish for “uninhibited” use of the island, the Pentagon wanted to expand U.S. facilities there. The expulsion of the Chagossians, who had inhabited the island since the 18th century, had recently been completed, thus removing any barrier to expansion once the British agreed.
NPL, NSC Files, box 731, United Kingdom Vol. IX, October 1973
With Heath’s decision to forego MIRVed Poseidon, Kissinger’s aides prepared a package to formalize President Nixon’s approval of further cooperation with the British on Super Antelope. Hyland and Lodal correctly noted that it was “easier to accommodate the British decision on improving the Polaris than had the UK chosen to procure the Poseidon technology.” On 17 January, Nixon approved a program of cooperation and Kissinger sent out a memorandum to the national security bureaucracy instructing them to take “the actions necessary to insure [sic] that this program can go forward.” In his letter to Heath, Nixon wrote that “innovative aspects of the [Super Antelope] project may pose problems,” which was a way to absolve the U.S. of any responsibility if the system failed in some way.
The day before Nixon’s approval, Ambassador Cromer informed the White House that his government had approved the U.S. request to expand facilities on Diego Garcia. In his message to Kissinger about the decision, his deputy Brent Scowcroft observed that it was “interesting to note that the British themselves are doing what Schlesinger wanted to do—linking Diego Garcia with the nuclear programs.” Thus, the pattern of close U.K.-U.S. military cooperation continued, even with U.S. discontent over the Super Antelope decision.
DNSA; from GRFPL, National Security Adviser's Files, Presidential Country Files for Europe and Canada, box 15, United Kingdom (4)
With Prime Minister Wilson slated for a visit to Washington, Denis Clift provided Kissinger with an overview of pending defense issues, including Diego Garcia, the nuclear use consultative agreement, and the status of U.S. support for Super Antelope. Clift reminded Kissinger, although he might not have needed a reminder, that the purpose of Super Antelope was to “assure British penetration of the Moscow ABM complex in an extreme ‘go it alone scenario.’” That was somewhat more than the capability described in Heath’s letter to Nixon, but it conveyed the essence of the “Moscow Criterion.”
By the time of the Wilson visit, the British had a new code-name for their project: “Chevaline.” Whether and when the United States learned about that remains to be learned. The matter was so secret that few members of Wilson’s cabinet knew about the project. How exactly Chevaline would operate to crack Soviet missile defenses was unresolved, and it would take a few more years for the British to develop the complex system of penetration aids along with the two nuclear-armed reentry vehicles for each Chevaline-modified Polaris missile. Developing and producing the new system fell behind schedule and costs mounted: it was not until 1982 that a British submarine equipped with Chevaline RVs went out on patrol.
II. The Trident Decisions
RG 59, Cyrus Vance Chron Files; Box 9, unlabeled file
Even before the British deployed Chevaline, they remained interested in trying to get what Ambassador Cromer had called “the best”—MIRVed SLBMs. They were not sure whether Washington would be receptive, but in January 1979 at the Guadeloupe Summit, British Prime Minister James Callaghan asked President Jimmy Carter about the possibility of acquiring Trident I missiles, which were then being deployed on U.S. Poseidon and Ohio-class submarines. Trident I had a range of 4,000 nautical miles and could carry up to eight highly accurate MIRVs, with yields of 100 kilotons. With the high costs of the Chevaline, the British believed that U.S. sharing of a strategic delivery system would keep their costs down. Carter did not expect the British request, but he gave a positive reply to Callaghan. Then Labour lost its majority in Parliament to the Tories and Margaret Thatcher became prime minister on 4 May 1979.
A few weeks after the Conservatives took power, Secretary of State Cyrus Vance was in London for several days of talks at Downing Street and Whitehall on a broad range of subjects, including the Middle East. He met with Defence Minister Francis Pym and the latter mentioned British interest in U.S. support for post-Polaris options. Vance assured Pym that cooperation would continue, that SALT would not limit any technology transfer commitments, and that the British should continue their post-Polaris planning. Vance “would convey this message to Mrs. Thatcher tomorrow.”
Vance and Pym also discussed the problem of NATO’s theater nuclear forces, a debate triggered by concern over Soviet SS-20 missile deployments. Both agreed on the importance of “modernizing” NATO forces by deploying Ground Launched Cruise Missiles (GLCMs), but neither were sure whether key countries such as Belgium, Italy, the Netherlands, or West Germany would agree to sponsor deployments. The problem of West Germany was particularly difficult because the Germans did not want to be a bigger Soviet target and did not want to take public positions that were inconsistent with “Ostpolitik.” Another difficult issue was how to relate arms control objectives with decisions to upgrade NATO’s nuclear posture.
Jimmy Carter Presidential Library (JCPL)
During discussions with Deputy National Security Adviser David Aaron, British officials said they were strongly interested in the MIRVed Trident C-4 because it would enable the British to maintain about 250 warheads “on station.” Aaron responded that the U.S. had not decided on whether to supply MIRVs but wanted more talks with British officials so they will get a better idea “of what we are willing to provide.” In late September, Cyrus Vance took the matter further by telling British Foreign Secretary Peter Carrington that he would strongly recommend to President Carter that the U.S. make available the Trident C-4 and its MIRV technology.
Before Brzezinski signed this memorandum, the Thatcher government had completed its internal review, contained in the Duff-Mason report, of nuclear force requirements that its Labour predecessors had initiated. The British were reaching the conclusion that the MIRVed Trident C-4 system would be necessary to provide a long-term capability to strike and destroy Moscow and other Soviet cities. As before, the British believed that nuclear forces were essential to keep the United Kingdom at the top table of the great powers and to ensure that France was not the only nuclear weapons state in Western Europe.  In October 1979, Brzezinski informed President Carter that the British were nearing a decision on their post-Polaris system. The Carter administration, however, did not want a formal request from London until NATO had made decisions on long-range nuclear forces and until SALT II was ratified. Both needed to get done first so that Trident did not provide “excuses” for European Allies to avoid participation in TNF and for the Soviets for “scuttl[ing]” SALT. According to Brzezinski, a letter to Prime Minister Thatcher requesting a delay was in the works.
The letter that Brzezinski mentioned (see Document 22) was prepared that same day. In it, Carter assured Thatcher that his response to a British request for Trident would be “affirmative.” Yet for the reasons outlined by Brzezinski, especially the TNF issue, he asked her to delay the request, until he could meet with her in December, when they could discuss the timing of the request. While the Trident decision was consistent with the NATO TNF program, the Carter White House worried that European allies would see Trident as an excuse for not going forward on TNF. The decisions on that matter were in the works, with NATO considering an “Integrated Decision Document,” that would spell out plans for deployments of hundreds of GLCMs in the United Kingdom, Belgium, Italy, and the Netherlands, and the deployment of Pershing II missiles in West Germany.
David Aaron hand-delivered the Carter letter to the British, who appreciated its “affirmative approach” and were willing to accept some delay in the decision-making process. While the British wanted to make an internal decision on Trident early in November, that troubled Aaron who worried it might leak. He urged them to delay their own decision-making process “as long as possible.” Deputy Cabinet Secretary Robert Wade-Gery realized that Thatcher should not make a request when she met Carter in December, but the British “inner cabinet” had to work on an initial decision.” Moreover, it would be possible to “stage manage” the decision so it would not have an adverse effect on TNF and SALT.
Aaron reported that the Carter letter had a good impact, and that the British would work with the U.S. to ensure that the Trident issue did not “come to a peak either with the Allies or the Soviets in the next few months.”
In her reply to President Carter, Thatcher observed that the British government had not yet made a final decision on its post-Polaris system, but that it was “good to know” that the U.S. would make the MIRVed C-4 system available to the United Kingdom. On the timing of a British request and other substantive matters, Thatcher would discuss that with him during their December meeting in London.
The Anglo-American agreement permitting the exchange of sensitive nuclear weapons data had been extended several times since 1958. In late 1978, the two countries agreed that the arrangement should be extended for five more years, and Assistant Secretary of State Reginald Bartholomew and British Embassy official John Robinson signed an amendment to that effect. The amendment would be submitted to Congress for the required 60-day period of review and if there were no objections it would enter into force. The agreement remained relevant to the nuts-and-bolts of U.K.-U.S. nuclear diplomacy, such as arrangements to provide the British with “special nuclear material” for the Trident warheads (see Document 27).
U.S. documents on the Carter-Thatcher meeting on 17 December 1979 are not available, but the gist of their conversation on Trident was that U.S. agreement to a British request would depend on SALT ratification. The Soviet invasion of Afghanistan a few days later made that unlikely, but the Carter White House continued to stall during early 1980, which discomfited London. That led to British pressure on the White House to decide.
Before a Special Coordinating Committee meeting was held in mid-March 1980, NSC staffer James Thomson reviewed the alternatives with Brzezinski: as the SCC saw it, the two basic options were concluding the deal in April or waiting until late April to decide whether to go for SALT ratification first or make a deal right away. Thomson wanted to “get on” with a decision, because waiting longer to decide was “risky”: delays caused by hopes about SALT ratification would be poorly received in Congress. And the British were not likely to accept long delays because they wanted a “date certain” for an agreement. Thus, Thomson proposed that the U.S. agree to an announcement either in late April, or if it decided to try for SALT ratification, late summer.
Thomson preferred to “forget the SALT link” and go for an early meeting to make a “vivid demonstration of US-UK solidarity.” But if the U.S. scheduled an early April meeting with the British to discuss options, one issue that would have to be covered was the U.S. “inability to make a firm commitment to supply them the plutonium they will need through the Eighties to build their new warheads.”
For Thomson, “solidarity” with London had a price: the payment of U.S. research and development costs. Under the law, the British would be required to pay $400 million, but if the U.S. followed the 1963 Polaris Sales Agreement, the charge would be $100 million. The Defense Department was willing to accept that in exchange for “quids”, such as British improvements in conventional defenses and British air defense for U.S. bases in the United Kingdom. Thomson believed that would not fly with Congress and that quids had been discussed with the British without reference to cuts in R&D charges. Thomson believed that the U.S. should ask for the entire $400 million, though that was far from the final U.S. position. 
NSC staffer Thomson provided his colleagues with a draft of the proposed exchange of letters between the president and prime minister that could be used once a decision had been made on the timing of an agreement. As he noted, the Special Nuclear Material situation (a reference to the plutonium problem cited above) was “murky,” so it was possible the sentences about SNM in the draft letter would need to be deleted.
Recounting the Special Coordinating Committee’s discussion of the Trident issue, Brzezinski reported to Carter that most of the participants agreed with Secretary of State Vance that the U.S. should “give the British a firm date,” perhaps in June, after the Belgians had made their decision on Theater Nuclear Force. Brzezinski expressed “uneasiness,” worrying that a decision and the SALT complications could create political problems for the President and that Thatcher should be asked if she would wait until 1981. Vance and Secretary of Defense Brown demurred, arguing that asking the British to wait risked creating “serious concern in Britain about our commitment” and raising the danger of “leaks that would be harmful politically.”
Commenting on Brzezinski’s point about waiting until 1981, Thomson believed that waiting that long “courts political disaster far more than moving ahead now or in June” because it would raise the president’s vulnerability “from the Right.” Stalling on Trident, especially because it involved a “loyal ally,” would add to the litany of “soft on defense” charges, such as the neutron bomb and the B-1 bomber. In addition, information on the delay could leak from the British side or from U.S. agencies, such as the Navy, no matter how closely the matter has been held.
Thomson mentioned the “36-B” review, a reference to an article in the Arms Export Control Act requiring notice to Congress of sales like the Trident. He saw no problem: if the U.S. opted for a decision in June or July there would be ample time to take it to Congress.
Produced either by NSC or State, this review of U.S support for Trident missiles for the United Kingdom identified several elements, including dedication of the missiles to the SACEUR target list, improvement in NATO “striking power,” “reaffirmation” of the U.S.-British strategic relationship, and “reinforcement of the Atlantic alliance.” The missiles and warheads would be the equivalent of seven percent of total Soviet strategic forces, the same ratio that obtained when the British Polaris force became operational in 1970.
To develop support for the Trident agreement, consultations with the French and the West Germans and other NATO allies would be necessary. For example, French Gaullists were likely to be critical of the agreement because Trident would provide the British with advantages lacked by French SLBM forces. The paper includes talking points that could be used in discussions with President Giscard d’Estaing and his associates to help them “contain” any domestic controversy. With respect to West Germany, “military and political circles … should welcome the announcement as evidence of reinforced US commitment to NATO.”
Noting that opponents of the TNF decision to deploy cruise missiles in Western Europe would argue that the Trident represented an alternative to TNF, the U.S. had counterarguments, for example, that the British were major supporters of TNF and Trident, and that dropping TNF would weaken the commitment to NATO: it would amount to “decoupling” and “nuclear regionalization.”
One point that James Thomson did not include in his discussion of quids (see previous documents) was an especially sensitive matter: the U.S. base at Diego Garcia. That was one of many items, from the hostage crisis in Iran to the situation in Afghanistan and beyond, that was on list prepared for a discussion between Deputy Secretary of State Warren Christopher and Vice President Walter Mondale in June 1980. The point on “Bases” demonstrated that expanded U.S. access to Diego Garcia and “greater flexibility” in using the island was one of the secret conditions that the Carter administration linked to the provision of Trident C-4 missiles. According to the paper, “Diego-Trident package now in place.” Apparently President Carter spoke about the matter with Prime Minister Thatcher at the economic summit which had just been held in Venice. A huge build-up of military basing arrangements on the island was about to unfold.
Rather than risk any further delay on the Trident issue, the Carter White House worked out an arrangement with the British to make an announcement in mid-July 1980. Senate Majority Leader Robert Byrd (D-WVa), then in Tokyo, had to receive some notice, so to keep him informed the White House sent a back-channel message. Noting that both President Carter and Prime Minister Thatcher had reached agreement on the Trident C-4 (through the exchange of letters), Brzezinski informed Byrd that Thatcher would be making an announcement in the House of Commons on 15 July.
Brzezinski informed Byrd of the strategic rationale for the decision, including continuation of the “special relationship” with the British. To cover R&D costs, the British would be charged five percent, $100 million (not the $400 million that had been discussed earlier); they further agreed to defend U.S. bases in the United Kingdom with the Rapier air defense missile system, which was “worth another $100 million to us over the next 20 years.” The British also declared that they would try to “take advantage of the economies” made available through cooperation with the U.S. on Trident by “reinforc[ing] [their] efforts to upgrade conventional forces.” The quid concerning Diego Garcia was not mentioned but the understanding had helped keep the price down.
Accordingly, on 15 July 1980, Defense Minister Pym announced the decision and the exchange of letters between Carter and Thatcher. The announcement was made in a hurry because The New York Times was about to publish the story (based on a U.S. leak), which meant that Thatcher could not brief her cabinet in advance. Until that point, she had kept a tight lid on internal discussion.
Copy from Matthew Jones (also available on Wikipedia)
In this lengthy paper, the British Defense Ministry explained why it had concluded that the “Trident system is the right choice for Britain.” The idea that British independence depended on a singular strategic nuclear role pervaded the discussion as did the related assumption that the United Kingdom was a “second centre of decision-making” in the North Atlantic alliance. Key elements of the argument are in paragraphs 9 through 12, where it was assumed that a British SLBM force would be a significant force supplementing the primary U.S. strategic deterrent. To make that possible, the United Kingdom needed a force that could pose a “massive threat on its own.” Thus, if the United States held back from a conflict with Moscow “the British force could still strike a blow so destructive that the penalty for aggression would have proved too high.” Putting it another way, although holding back on sensitive details, the Defense Ministry declared that its “concept of deterrence is concerned essentially with posing a potential threat to key aspects of Soviet state power.”
Compared to other systems, including Poseidon and cruise missiles, the British concluded that MIRVed Trident would provide “excellent margins of long-term insurance against further advances in Soviet ABM and ASW capability and improved guidance techniques give better accuracy than earlier systems have offered.” While the U.S. was working on a Trident II system it would not decide to proceed for several years. Therefore “Our own choice now could not be made dependent on uncertain possibilities like this.”
CIA FOIA Database
During an early visit to the United Kingdom, Secretary of Defense Caspar Weinberger met with Prime Minister Thatcher, telling her that he was a “strong believer in the special relationship.” Demonstrating the continuity from Carter to Reagan in nuclear policy, the Trident I arrangements was a given in that context and Thatcher mentioned that when Trident went before Parliament she hoped to win as many Labour votes as possible. The “UK must have its own strategic nuclear deterrent.” Thatcher had previously opposed Parliamentary debate over Trident because she worried abouts its impact on relations with Washington, but finally accepted it. When the matter went to the House of Commons on 3 March 1981, it approved the agreement by 316 to 248.
Weinberger and Thatcher also discussed TNF matters, with Weinberger declaring that Washington would go ahead with the December 1979 deployment decisions. While Weinberger liked the idea of Enhanced Radiation Weapons (ERWs) for anti-tank missions, he realized that they made people “nervous.” Citing the argument that ERWs lowered the nuclear threshold, which was difficult to refute, Thatcher worried about “nuclear pacificism” and saw it important to uphold the TNF decision. When Carrington wondered whether TNF would get “unstuck” if arms control talks did not begin with Moscow, Weinberger argued that the West “should enter such negotiations from a position of strength” [implicitly deployments first].
Ronald Reagan Presidential Library
Complicating British choices was a U.S. decision to move forward with the Trident D-5 missile and to take the C-4 out of service. With its high accuracy and greater payload capacity, the D-5 provided far greater lethality than the C-4: an accuracy of some 90 meters CEP [circular error probable] (compared with a CEP of 0.24 for Trident C-4) and a capability to carry a 475-kiloton warhead (compared with 100 kilotons for the C-4), although it could also carry smaller warheads. Moreover, the D-5 range was some 7,500 nautical miles compared with 4,000 for the C-4, although the British did not require such a capability. While the D-5 would be more expensive than the C-4, the British did not want to replace Polaris with an outmoded system.
With the U.S. decision on the D-5 having been made, Weinberger informed Thatcher that the U.S. would make it available “should you desire to buy it.” Weinberger had met with Defense Minister John Nott, who gave him the impression that an “early” U.S. decision would assist British defense planning. Thus, Weinberger wanted to inform Thatcher of the U.S. decision ahead of the public announcement. The British were already spending money toward the acquisition of the C-4 and the U.S. wanted to reduce unnecessary expenditures that could be better spent on conventional forces. The U.S. was already concerned that the British were making excessive cuts in military spending.
With the receipt of Weinberger’s letter, Thatcher and her close advisers deepened their review of the options while keeping the matter secret from the full Cabinet. As before, the British goal was a missile force that could infiltrate Soviet defenses and threaten the destruction of Moscow and other major cities. It was not until 21 January 1982 that Thatcher officially told her Cabinet and then informed Reagan and Weinberger that she wanted to go ahead with the D-5 and to begin discussions with the U.S. government on that matter.
The National Archives (TNA) (United Kingdom), CAB 128/175/1 (copy courtesy of Matthew Jones)
This summary record recounts Prime Minister Thatcher’s review to the Cabinet of the process that led to her decision to support acquisition of Trident II instead of Trident I as the basis for an “independent strategic nuclear deterrent.” The key problem was negotiating “satisfactory” terms with Washington because of the system’s technological complexity and capital costs that were larger than for the C-4. Nevertheless, D-5 operating costs would be lower because “it would be operating in parallel with an American programme.” A British team would visit Washington for talks and the results would be brought back to the Cabinet for a decision.
Ronald Reagan Presidential Library, Executive Secretariat, NSC, Country File: United Kingdom (01/25/1982-02/11/1982 (Too late to File) [sic]
U.S. negotiators agreed with the British that the key problem in the Trident II negotiations was reaching a price that both sides could accept. The cost of the system would be $3.75 billion but there would be additional costs: some $700 to 900 million for R&D costs. Secretary of State Alexander Haig and Deputy Defense Secretary Frank Carlucci found it in the U.S. interest to waive some of the costs, which President Reagan had discretion to do. They anticipated that the British would offer some $275 million, including “offsets” (or quids) to which the U.S. could respond with a proposal close to the Trident I agreement of a few years earlier. That could include new offsets involving actions that the British could take and that would both save money for the United States and “bolster Western defenses.”
Ronald Reagan Presidential Library, Executive Secretariat, NSC, Country File: United Kingdom (01/25/1982-02/11/1982 (Too late to File) [sic]
The first round of U.K.-U.S. negotiations over Trident disclosed each country’s position, but the British argued that Washington was asking for too much. They agreed, however, to come back with additional offsets to lower the price. Carlucci and State’s Walter Stoessel were “optimistic that we can bridge the differences.”
TNA, CAB 128/175/3 (copy courtesy of Matthew Jones)
It did not take long to bridge the cost differences. As Defense Minister John Nott reported, the Reagan administration did not press the British hard—the offsets on conventional forces were general and some of the specific concessions, such as keeping two assault ships, the Royal Navy was going to retain in any event. On the R&D levy, the British had to pay $116 million which was far less than the initial price of $222 million proposed by U.S. negotiators.
Because of Central American concerns, the U.S. had been worried about a precipitate British withdrawal from Belize. London, however, agreed to continue to provide training for Belize’s armed forces so that they could better withstand pressures from Guatemala. As Suzanne Doyle has argued, the Reagan administration gave the British favorable terms on the D-5 not so much because of a “special relationship” but because of the “convergence of Anglo-American interests.” Through the 1982 agreement, Washington supported a Conservative-led Britain that upheld U.S. security and political interests in NATO and elsewhere, while the British acquired the advanced nuclear forces that they believed were essential to advance their overall political and military position.
London and Washington signed a formal agreement on the D-5 later in the year and construction of the first British Trident-capable, Vanguard-class submarine began in 1986. The first Vanguard submarine went on patrol eight years later, thus enabling the British to begin withdrawing the Chevaline warhead.
Nott’s report on the decision to go ahead with Trident II included several points that could not be made public, although they were standard themes in British nuclear discourse. A strategic nuclear force under “British national control” was “essential” because “no one could foresee what might happen over the next 30-40 years to the North Atlantic Treaty Organisation or to the United States attitude to the defense of Europe.” This was more specific than the general points made in the July 1980 Defense report on Trident. Indeed, less than 40 years later, the UK would face a U.S. president whose commitment to European security was dubious. Besides concern about long-term U.S. constancy, there was the rivalry with the French. During the discussion, someone, probably Carrington, said that without upgrading British nuclear forces, “it would have been unthinkable to leave France as the only effective nuclear power in Western Europe.” 
III. GLCMs and Updating Murphy-Dean
TNA, CAB 130 (1224) (copy courtesy of Oliver Barton/London School of Economics)
While the Trident II issue was resolved, negotiations with Washington over the deployment of GLCMs to Greenham Commons Royal Air Force base under the TNF program were not completed. The deployment was to begin in November 1982, but the issue was politically explosive owing to the resurgence of anti-nuclear activism in the United Kingdom. Moreover, members of the Parliamentary Opposition were pressing for information about the control arrangements and argued for a dual-key system such as had been used for the Thor IRBMs. Thatcher and her advisers wanted to bring the 1958 Murphy-Dean agreement (see Part I of this posting, Document 5) up to date in order to accommodate the GLCM deployments by including language that deploying the missiles off-base and firing them would require a “joint decision” by U.S. and U.K. authorities. While U.S. diplomats worried that “joint decision” language would lead to pressure from Italy and other governments for comparable wording, the Thatcher government believed that “joint decision” was necessary to reduce pressure from Opposition M.P.s who sought explicit “dual key” arrangements. For Thatcher and her colleagues, “dual key” could have “damaging repercussions” for relations with Washington by implying that the British believed that it was necessary to “restrain” the United States "rather than to ensure that she was ready to defend the allies.”
TNA, CAB 130 (1224) (copy courtesy of Oliver Barton)
British and U.S. diplomats had made progress in the updating of Murphy-Dean, but U.S. negotiators argued that “joint control” arrangements over the GLCMs should not apply to SACEUR decisions for an emergency re-deployment of the missiles, off-base, in the event of a crisis. The argument was that the “assured survivability of the cruise missile force was important for deterrence, and it would therefore be appropriate to agree that SACEUR should have authority to deploy the missiles off-base in an emergency.” The Parliamentary Opposition was pressing so hard for dual-key arrangements that it might have been necessary to accede to it. To help the government “manage” the public debate, there was general agreement on the importance of securing “President Reagan's agreement to state in public that no President would authorise the use of nuclear weapons based in the United Kingdom without the Prime Minister's consent.” Apparently British concerns reached the White House and during an interview on 26 May 1983 at the Williamsburg Economic Summit, Reagan stated that “I don’t think either one of us will do anything independent of the other. This constitutes a sort of veto power, doesn’t it? But we have an understanding about this and would never act unilaterally with any of our allies on this.” By then, U.K.-U.S. negotiations had updated the Murphy-Dean agreement (see Document 43).
TNA, CAB 196/124 (copy courtesy of Tristan Stoddart, Swansea University)
The 1983 British Parliamentary elections led the British Cabinet Office to go through the routine procedure of preparing transition papers in the event of a new prime minister. This comprehensive report reviewed the U.K.’s nuclear release procedures, unilateral in extreme emergencies and bilateral with allies otherwise, including predelegation to the Royal Air Force and “Last Resort” procedures for use of SLBMs if the prime minister or her deputies were out of action.
Attached to the report were copies of the Wright-Eagleburger Agreement along with a report on “Anglo-American Understandings on Nuclear Release Procedures: President-Prime Minister Correspondence,” which provided an overview of the history of the routine exchanges of letters from the Kennedy administration to the most recent exchanges between Reagan and Thatcher. As the British had agreed, the Wright-Eagleburger Agreement authorized NATO to deploy British-based GLCMS in an emergency. Also included was a report on “Consultation Understandings” with the West German prime minister concerning the use of British nuclear weapons stored in West Germany.
State Department FOIA Release
Written during a period of uncertainty in the U.K.-U.S. relationship, where British anti-Americanism was becoming more salient, this INR report nevertheless found that “it would be difficult to conceive of a British Prime Minister who would be more sympathetic toward the US,” than Thatcher. Yet her possible successor, British Labour Party leader Neal Kinnock, had taken strongly anti-nuclear positions, e.g., removing GLCMs and U.S. nuclear-capable aircraft from the U.K. Even if Labour did not win in the next election, divergences in interests could weaken ties with the United States, such as tensions between the “special relationship” and membership in the EC. The Strategic Defense Initiative was also a problem for London: “undermin[ing] the rationale for Trident because a Soviet counterpart to SDI conceivably might be effective against Trident.” Moreover, the “contraction of British power has narrowed areas of significant U.K.-U.S. cooperation to the Persian Gulf, southern Africa, the Caribbean, and the Mediterranean.” Nevertheless, for the U.S., even a small British role added “legitimacy to joint enterprises” and “provide[d] valuable real estate,” while giving London “the chance to restrain US actions.”
. See Hans Kristensen, “British Defense Review Ends Nuclear Reductions Era,” Federation of American Scientists, May 2021.
. Adam Taylor, “The Gulf Between Boris Johnson and Joe Biden,” The Washington Post, 10 June 2021.
. Stephen Twigge, “Operation Hullaballoo: Henry Kissinger, British Diplomacy and the Agreement on the Prevention of Nuclear War”, Diplomatic History, 33 (2009), 689–701.
. For “Option M,” see Helen Parr, “The British Decision to Upgrade Polaris, 1970–4,” Contemporary European History (2013): 253-274.
. For the “Year of Europe” and its implications, see Thomas Schwartz, Henry Kissinger and American Power: A Political Biography, 217-218.
. Parr, “The British Decision to Upgrade Polaris, 1970–4,” 253-274.
. Parr, “The British Decision to Upgrade Polaris, 1970-4,” suggests at 271-272 that the British could afford Poseidon, but that the economic crisis made it more difficult to convince Parliament to approve a purchase.
. David Vine, Island of Shame: The Secret History of the U.S. Military Base on Diego Garcia (Princeton University Press, 2009).
. Thomas Robb, “Antelope, Poseidon or a Hybrid: The Upgrading of the British Strategic Nuclear Deterrent, 1970–1974,” The Journal of Strategic Studies 33 (2010): 813.
 . The first Super Antelope test took place on 23 May 1974, test “Fallon,” the 750th test (since Trinity) in the Department of Energy’s comprehensive list of tests. The next test, on 26 August 1976, was the 800th.
. “Thatcher Went Behind Cabinet’s Back with Trident Purchase,” The Guardian, 30 December 2011; Kristan Stoddart, Facing Down the Soviet Union: Britain, the USA, NATO and Nuclear Weapons, 1976-1983 (New York, Palgrave Macmillan, 2014), 150.
. John Baylis and Kristan Stoddart, “Britain and the Chevaline Project: The Hidden Nuclear Programme, 1967–82,” The Journal of Strategic Studies 26 (2003): 124-155,
. Suzanne Doyle, “Preserving the Global Nuclear Order: The Trident Agreements and the Arms Control Debate,” International History Review 40 (2018): 1180.
. For the British debates, see Stoddart, Facing Down the Soviet Union. See also Suzanne Doyle, “The United States Sale of Trident to Britain, 1977–1982: Deal Making in the Anglo–American Nuclear Relationship,” Diplomacy & Statecraft 28 (2017): 477-493. See also Anthony Eames, “The Trident Sales Agreement and Cold War Diplomacy,” Journal of Military History 81(2017): 163-186.
. Doyle, “The United States Sale of Trident,” 481.
. Stoddart, Facing Down the Soviet Union, 136.
. For useful coverage of the financial issues and the Pentagon’s approach to “quids,” see Doyle, “The United States Sale of Trident,” 482-484, as well as Stoddart, Facing Down the Soviet Union, 140-142
. Viner, Island of Shame, 8.
. Stoddart, Facing Down the Soviet Union, 143.
. Stoddart, Facing Down the Soviet Union, 143, 150.
. Stoddart, Facing Down the Soviet Union, 189-192.
. Doyle, “The United States Sale of Trident,” 487. See also Doyle,” A Foregone Conclusion? The United States, Britain and the Trident D5 Agreement,” Journal of Strategic Studies 40 (2017): 867-894, and Stoddart, Facing Down the Soviet Union, chapter 7.
. “Thatcher Went Behind Cabinet’s Back with Trident Purchase,” The Guardian, 30 December 2011.
. “Interview with Foreign Television Journalists, May 26, 1983,” Public Papers of the President of the United States: Ronald Reagan, Book I: January 1 to July 1, 1983 (Washington, D.C.: Government Printing Office, 1984), 774.