Polaris Sales Agreement
The Polaris Sales Agreement was a bilateral treaty signed on 6 April 1963 between the United States and the United Kingdom, whereby the US government agreed to supply the UK with Polaris A-3 submarine-launched ballistic missiles, excluding warheads, to equip British-built nuclear-powered submarines as part of the UK's strategic deterrent program.[1][2] This agreement implemented the Nassau Agreement reached between US President John F. Kennedy and UK Prime Minister Harold Macmillan in December 1962, following the cancellation of the Skybolt air-launched missile project, and provided the UK with access to US missile technology while preserving its sovereign control over targeting and deployment decisions.[3][4] Under the terms, the UK committed to assigning its Polaris force to NATO while retaining the option for independent use in supreme national emergencies, fostering deepened transatlantic alliance cooperation amid Cold War nuclear tensions.[1][5] The agreement was later amended in 1982 to encompass the Trident missile system, extending US-UK collaboration on sea-based nuclear deterrence into subsequent decades.[1][6]Historical Context
Preceding Developments
The United Kingdom's nuclear deterrent originated in the post-World War II era, with the development of atomic weapons independent of the United States after the 1952 Monte Bello Islands test. By the late 1950s, the V-bomber fleet—consisting of the Avro Vulcan, Handley Page Victor, and Vickers Valiant—formed the backbone of the strategic force, armed primarily with free-fall gravity bombs like the Blue Danube for delivery against Soviet targets.[7][8] Advancing Soviet air defenses diminished the V-bombers' penetration capability, prompting exploration of ballistic missile alternatives. The Blue Streak intermediate-range ballistic missile program, initiated in 1956, aimed to provide a land-based solution but was abandoned on 13 November 1960 due to its fixed-site vulnerability to preemptive strikes, liquid-fueled inefficiencies, and escalating costs exceeding £100 million.[9] This left the V-force without a clear successor, eroding confidence in its long-term viability amid fiscal constraints and technological shifts toward submarine-launched systems.[8][9] In response, Prime Minister Harold Macmillan negotiated the acquisition of the U.S. GAM-87 Skybolt air-launched ballistic missile in 1960, intended to extend V-bomber relevance by enabling standoff launches with a 1,000-nautical-mile range and inertial guidance. However, Skybolt's development encountered persistent failures in flight tests—only one partial success in over a dozen attempts—and costs ballooned from $700 million to over $1 billion, leading U.S. Secretary of Defense Robert McNamara to recommend cancellation on 7 November 1962.[9][10] The decision, formalized shortly thereafter, precipitated a crisis for the UK's deterrent posture, as Skybolt represented the primary upgrade path without viable domestic alternatives.[10][11]Nassau Agreement
The Nassau Agreement emerged from a crisis in Anglo-American defense cooperation triggered by the United States' abrupt cancellation of the Skybolt air-launched ballistic missile program in late November 1962, a system the United Kingdom had committed over £100 million to integrate with its V-bomber force for maintaining an independent nuclear deterrent.[12] British Prime Minister Harold Macmillan, facing domestic political pressure and the prospective obsolescence of Britain's aerial nuclear delivery capabilities amid advancing Soviet air defenses, urgently sought assurances from President John F. Kennedy during a summit in Nassau, Bahamas, from December 17 to 21, 1962.[12] The talks, attended by key advisors including U.S. Secretary of Defense Robert McNamara and British Foreign Secretary Lord Home, shifted focus to substituting Skybolt with the more advanced U.S. Navy's Polaris submarine-launched ballistic missile (SLBM) system as a viable alternative for Britain's sea-based deterrent needs.[12] In the joint communiqué issued on December 21, 1962, Kennedy and Macmillan agreed that the United States would supply Polaris A-3 missiles—capable of ranges exceeding 2,500 nautical miles—without nuclear warheads, along with associated launch equipment and technical support, to equip British-built submarines on a continuing basis sufficient for a credible deterrent force.[13] The United Kingdom committed to constructing its own resolution-class submarines, estimated at four to five vessels, and developing indigenous warheads and targeting systems, while initially assigning the submarines to a proposed NATO multilateral nuclear force (MLF) under Supreme Allied Commander Europe (SACEUR) operational control.[13] This assignment included provisions for a British veto to withdraw forces for "supreme national interests," preserving London's sovereign decision-making over nuclear release, a concession reflecting Kennedy's aim to integrate European nuclear assets into NATO while accommodating Macmillan's insistence on retaining an independent British capability amid decolonization strains and the 1958 U.S.-UK Mutual Defence Agreement's limitations on fissile material sharing.[13][12] The agreement's framework emphasized interoperability and cost-sharing, with the U.S. providing missile fire-control solutions and refurbishment services at no additional charge beyond initial acquisition, contingent on NATO-wide contributions to Polaris technology.[13] It explicitly excluded warhead transfers, requiring the UK to leverage its own atomic weapons enterprise, bolstered by prior U.S. plutonium supplies under the 1958 treaty.[14] While hailed in Washington as advancing alliance unity—particularly against French President Charles de Gaulle's independent force de frappe ambitions—the deal faced U.S. congressional skepticism over technology transfers and British parliamentary debate on dependency risks, yet it resolved the immediate Skybolt impasse without derailing the "special relationship."[12] This verbal understanding laid the groundwork for the formal Polaris Sales Agreement signed on April 6, 1963, marking a pivotal step in transitioning Britain's nuclear posture from air to submarine-based vectors.[1]Negotiations and Terms
Key Negotiators and Timeline
The Polaris Sales Agreement negotiations commenced immediately following the Nassau Agreement of December 21, 1962, between U.S. President John F. Kennedy and UK Prime Minister Harold Macmillan, which outlined the provision of Polaris missiles to the United Kingdom.[15] Detailed bilateral talks between U.S. and UK officials, including military and civilian representatives, began in January 1963 to establish the specific terms for missile sales, technical support, and associated costs.[16] By March 1963, the British negotiating team, comprising Admiralty officials and civil servants, had finalized the agreement's provisions after discussions in Washington.[15] On the U.S. side, key involvement came from the Department of State and Department of Defense, with Admiral George W. Anderson, Chief of Naval Operations, contributing to early coordination.[15] The UK team focused on securing favorable pricing, fire control solutions, and long-term support mechanisms, reflecting Britain's need to maintain an independent nuclear deterrent amid fiscal constraints.[17] These negotiations addressed complexities such as missile specifications, delivery timelines, and integration with British submarines, culminating in the agreement's readiness for signature.[1] The agreement was formally signed on April 6, 1963, in Washington, D.C., by U.S. Secretary of State Dean Rusk for the United States and UK Ambassador David Ormsby Gore for the United Kingdom.[15] [18] This timeline bridged the high-level Nassau commitments with operational implementation, enabling the UK to procure up to 65 Polaris A-3 missiles by the mid-1960s.[1] The swift progression from Nassau to signing underscored the strategic alignment between the two nations post-Skybolt cancellation, though it required concessions on U.S. technology sharing.[17]Core Provisions of the Agreement
The Polaris Sales Agreement, signed on April 6, 1963, between the governments of the United States and the United Kingdom, formalized the sale of Polaris submarine-launched ballistic missiles (excluding warheads), related equipment, and support services to equip the UK's strategic nuclear deterrent. Under Article I, the United States agreed to provide these items, while the United Kingdom committed to their purchase, subject to prior understandings from the 1962 Nassau Agreement. The deal emphasized integration with the US Polaris program to leverage efficiencies, without imposing direct controls on UK operational use or targeting decisions.[2][1] Key supply provisions in Articles III, V, and X outlined US delivery of missiles, launching systems, fire control and navigation equipment, test gear, spares, technical documentation, and training, with initial missile check-out and certification handled by the US prior to transfer. The UK retained responsibility for constructing submarines and developing warheads, receiving interface data from the US but not proprietary nuclear propulsion details. Delivery occurred at UK sites, with reimbursable US assistance for installation and testing to ensure compatibility. Future modifications to the Polaris system were to be shared reciprocally under Article IV, promoting joint technological advancement without mandating adoption.[2] Financial terms in Article XI required the UK to cover production costs, a 5% surcharge on equipment to offset US research and development expenditures, replacement charges for consumed items, and actual costs for services, funded through a US-managed trust account for streamlined payments. Quality assurance fell to the US under Article VII, with equivalent standards to domestic production and UK observation rights, though the UK assumed liability for defects post-delivery. Article VIII stipulated UK indemnification of the US against third-party claims arising from hazards inherent in the supplied materials. Patent protections were secured by the US, with UK reimbursement for any settlements (Article IX).[2] Coordination mechanisms in Article II established executive agencies—the US Department of Defense and UK Admiralty—supported by project officers and a Joint Steering Task Group to oversee implementation. Security and non-proliferation restrictions in Article XIV prohibited UK transfer or disclosure of items or data to third parties without US consent, alongside mutual commitments to safeguard classified information. These provisions ensured operational independence for the UK while binding it to US technological and security frameworks, with no explicit veto over deployment or targeting retained by the US.[2]Implementation of the Polaris Programme
UK Submarine Construction
Following the Polaris Sales Agreement of April 1963, the United Kingdom initiated construction of four Resolution-class nuclear-powered ballistic missile submarines (SSBNs) designed to deploy the acquired U.S.-supplied Polaris missiles. These submarines were entirely constructed domestically, with the programme authorised in February 1963 to ensure rapid development. The design incorporated a modified Valiant-class hunter-killer submarine hull extended to accommodate a missile compartment for 16 Polaris A-3 missiles, powered by a British pressurised water reactor (PWR1). Construction was divided between two shipyards to accelerate delivery: Vickers Shipbuilding and Engineering in Barrow-in-Furness built HMS Resolution and HMS Repulse, while Cammell Laird in Birkenhead constructed HMS Renown and HMS Revenge.[19][20][21] Keel-laying for the lead ship, HMS Resolution, commenced on 26 February 1964 at Vickers, marking the start of physical construction. She was launched on 15 September 1966 and commissioned on 27 October 1967 after trials, including a successful Polaris missile firing in February 1968 off Cape Canaveral. HMS Repulse followed, with her keel laid on 12 March 1965 at the same yard, launched on 4 November 1967, and commissioned on 28 September 1968. At Cammell Laird, HMS Renown's construction began with keel-laying on 25 June 1964, leading to her launch in 1966 and commissioning in 1968. HMS Revenge, the final vessel, had her keel laid in 1965, was launched in 1967, and commissioned in September 1969. This parallel build strategy enabled all four submarines to achieve operational status by 1970.[22][20][23]| Submarine | Builder | Keel Laid | Launched | Commissioned |
|---|---|---|---|---|
| HMS Resolution | Vickers, Barrow-in-Furness | 26 Feb 1964 | 15 Sep 1966 | 27 Oct 1967 |
| HMS Repulse | Vickers, Barrow-in-Furness | 12 Mar 1965 | 4 Nov 1967 | 28 Sep 1968 |
| HMS Renown | Cammell Laird, Birkenhead | 25 Jun 1964 | 1966 | 1968 |
| HMS Revenge | Cammell Laird, Birkenhead | 1965 | 1967 | Sep 1969 |