In 1962 Britain undertook to make a complete change of approach to nuclear deterrence by moving from a delivery platform based on bomber aircraft to submarine-launched ballistic missiles (SLBM). This decision was arrived at over three days in Nassau in the Bahamas against a background of political panic. Its implications continue to shape UK deterrence policy today.
Since the 1960 cancellation of the Blue Streak intermediate-range ballistic missile (IRBM), the future UK deterrent was to be based on the Douglas Skybolt missile carried initially by the Mark 2 Vulcan bombers, to be succeeded by either a Mark 3 Vulcan or modified VC-10 airliners, capable of operating a Strategic Air Command-style airborne alert. This meant that nuclear-armed bombers could always be flying to prevent some of the force from being destroyed on the ground in a pre-emptive strike—a particular concern for a small land-based force in a country the size of Britain and relatively close to the Eastern bloc.
However, the United States’ cancellation of the incomplete Skybolt programme in November 1962 produced a domestic political crisis for the government of Prime Minister Harold Macmillan. The UK had no alternative strategy to secure the future of its nuclear deterrent and faced the possibility of becoming the first nation to leave the ‘nuclear club’; membership of which had cost the country so much effort and expense over the preceding 15 years. It was against this background that Prime Minister Macmillan, Foreign Secretary Lord Home, Ambassador to Washington Sir David Ormsby-Gore and Defence Minister Peter Thorneycroft travelled to Nassau to negotiate an agreement with the Kennedy administration that was to change the face of British Cold War strategy.
Macmillan’s preferred solution for the UK deterrent was the Polaris SLBM, which would be harder to target in a pre-emptive strike and more cost-effective, as it was based on readily available technology. This, however, was far from an uncontroversial position. Among the sceptics were the Royal Air Force, which naturally favoured the use of RAF-manned aircraft and were concerned about the personnel and budget cuts likely to accompany the loss of a significant defence role. Polaris was also dismissed by the Labour opposition, which declared in its 1964 election manifesto, 'it will not be independent and it will not be British and it will not deter.' Even the Royal Navy had misgivings about its new role, with the First Sea Lord, Sir Caspar John, lamenting 'this millstone of Polaris hung round our necks.'
The alternatives to Polaris would have been either to take over Skybolt development as a purely UK programme, or develop an entirely indigenous long-range standoff weapon to replace Blue Steel, the RAF’s newly operational bomber-carried missile with a 100 mile (160 km) range, in the 1970s. Both options carried significant risks in terms of financial cost, which had already led to the cancellation of several UK and US projects, besides being fraught with technical difficulties and vulnerable to defensive countermeasures which could undermine the system’s credibility and make it obsolete. The Nassau agreement enabled Britain to purchase and operate an up-to-date deterrent, which was explicitly assigned to NATO through Supreme Allied Commander Europe (SACEUR) except where 'supreme national interests' were at stake. This independence was to be guaranteed through national control of the firing chain. This represented a pragmatic solution to the prospect of Britain being forced to give up its nuclear status; a position held by elements of the US Administration where such national nuclear forces (i.e. British and French) were described as inherently dangerous due to their vulnerability and limited credibility.
The entry into service of HMS Resolution in 1968 led to profound changes in British nuclear force structures. The RAF lost the strategic role it had held, in theory at least, since its earliest days, and that had reached its apogee at the end of World War 2. From the mid-1960s the V-Bomber force lost two-thirds of its strength and was relegated to a theatre role in support of NATO. This force was, in due course, phased out in favour of smaller tactical aircraft. The RAF nuclear capability was retained until 1998 but was not renewed when the WE177 bomb reached the end of its life. With the 1980 decision to to procure the Trident missile, the RAF was further marginalised. The absence of a future strategic-range aircraft for the RAF meant that continuing with a submarine-based ballistic missile force was the only viable alternative by the 1980s.
Had the Polaris agreement not been reached in Nassau, Britain would have been left with difficult choices. Domestic completion of Skybolt might have resulted in extending the credible life of the bomber force and produced a new generation of strategic aircraft. However, the relative vulnerability of such a force compared with SSBNs would probably have forced Britain in this direction by the 1980s, though a totally indigenous development of submarines and missiles would probably have been beyond the UK’s means and would have required either significant cuts to other programmes or closer collaboration with other allies (in this case almost certainly France). The latter, in addition to presenting domestic political difficulties, might also have placed the 1958 Mutual Defence Agreement between the UK and the US under some pressure.
1962 has therefore defined the shape of Britain’s 21st century deterrent. The difficulty in intercepting ballistic missile warheads and detecting submerged nuclear submarines continues to make the SSBN an attractive platform for a deterrent force; especially for a nation fielding a single nuclear delivery system. Meanwhile the economy of force permitted by missiles armed with multiple independently targetable warheads allows a significant striking force to be deployed at relatively low cost compared to an equivalent air-based deterrent, due to the large numbers of aircraft, weapons and bases required. Once Britain had deployed an SSBN force and halted development of alternative platforms, it became extremely difficult to change the basis of the UK deterrent force, a situation highlighted by the Trident Alternatives Review. What began as a politically difficult decision in 1962 has become the cornerstone of UK nuclear policy. In fact, the 1962 Nassau agreement and the reliance on a submarine-based deterrent it generated led directly to the 1980 and 2016 decisions to acquire Trident missiles and Dreadnought class submarines, and will likely shape UK deterrence policy for decades to come.
© British Crown Owned Copyright 2018/AWE
Paul Burton is a Researcher with AWE plc and a Fellow of the Institute of Physics. His primary focus is on past systems and what they can teach us as well as the political and strategic climates in which particular decisions were made.
This paper is the work of the author, and all opinions and views expressed are his own and do not necessarily represent those of AWE, MoD, HMG or any associated organisation or its stakeholders.
Image credit: President Kennedy followed by British Prime Minister Harold Macmillan and his wife Dorothy, December 1961, National Archives