The beliefs of British Prime Ministers since 1941 about the nation’s security and role in the world have been of critical importance in understanding the development and retention of a nuclear capability.
Winston Churchill supported the development as a means of national survival during the Second World War. Attlee took the decision to develop a nuclear deterrent in 1947. Churchill, on returning to power in the early 1950s, was a strong supporter of developing thermonuclear weapons. Eden and Macmillan continued Churchill’s policies of trying to develop close nuclear ties with the United States, culminating in the 1958 Mutual Defence Agreement and the 1962 Nassau Agreement and 1963 Polaris Sales Agreement. Douglas-Home strongly supported Britain’s nuclear status as a means of highlighting Britain’s world role. Harold Wilson, after threatening to renegotiate the Nassau Agreement continued with the Polaris programme. In the early 1970s, Ted Heath flirted with the idea of some form of Anglo-French nuclear capability, but ultimately settled for a continuation of the close Anglo-American special nuclear relationship. On returning to office, Wilson secretly pursued the Chevaline improvement to Polaris, despite indications that the independent deterrent would not be renewed. This policy was continued by James Callaghan, even to the point where, had he remained in office, a successor to Polaris was close to being agreed with Jimmy Carter, the US President. It was left to his successor, Margaret Thatcher, to conclude the Trident C-4 and D-5 Agreements in 1980 and 1982. Those Agreements were subsequently supported by John Major and the governments of Tony Blair and Gordon Brown began the debate about the replacement of Trident. During David Cameron’s Coalition Government from 2010 there has been a clear determination to move on to a like-for-like replacement of Trident following the General Election in May 2015.
In the past seventy or so years there have been differences in the views of Prime Ministers about Britain’s world role and the level of nuclear capability required, but there has been a consistent belief that, in a largely anarchic, uncertain world, nuclear weapons have both political and strategic utility. That continuing support from the highest level of political leadership, both left and right, has been crucial in maintaining Britain’s nuclear status.
If the Prime Minister is so important in nuclear decision-making, this raises the question of what would have to change for Britain to give up its nuclear capability. There are three possibilities. One is that a Prime Minister is elected on a mandate to abolish British nuclear weapons unilaterally. This clearly cannot be ruled out, but the history of the period since the Second World War is that public opinion in general has been in favour of a British nuclear capability. There have been times during periods of the 1950s and 1980s when support for the Campaign for Nuclear Disarmament (CND) has been fairly strong, and when the Labour opposition (including its leader) has favoured giving up nuclear weapons, but there has never been a majority in favour of unilateral disarmament. This has led to a contemporary political consensus that any party advocating unilateral nuclear abolition would be unelectable.
A second possibility would be for a Prime Minister to change his/her mind in office and move from a pro-nuclear to an anti-nuclear stance. Again this cannot be ruled out as implausible, but any Prime Minister who did this would face the entrenched opposition of a wide-ranging establishment nuclear advocacy coalition, who have traditionally worked hard to back the Prime Minister of the day, and to campaign in favour of a British nuclear deterrent force. This powerful and influential coalition has consisted of eminent scientists and engineers, high-level military officers and key civil servants, as well as Ministers and other political supporters of the Prime Minister. There would need to be a truly extraordinary set of circumstances, such as a major nuclear accident, to create the political conditions for such a Prime Minister to succeed in a radical reversal of a policy which has been an important part of Britain’s self-identity as a great power in world politics.
The third possibility would be for a minority government to change its pro-nuclear position due to the need to form a coalition or an alliance with another anti-nuclear party in order to remain in power. This is the position which the Labour Party might find itself in following the next election. Should it be the largest party but with insufficient seats to form a government it might have to depend on the Scottish National Party (SNP) to form a government. For the SNP, the abolition of Trident is a key policy objective. Again, however, this route to unilateral disarmament, although possible, would seem to be unlikely. The SNP has indicated that it would not join a coalition with Labour, but might support it on an issue by issue basis. Initially this seemed to suggest that the future of Trident might not prevent a loose arrangement between Labour and the SNP. Subsequently, however, Ms Sturgeon the leader of the SNP told her Party Conference that the SNP would ‘stand firm and unwavering’ on ‘the obscene status symbol that is the new generation of Trident nuclear weapons’, indicating that it might be a red line in any negotiations with Labour. This clearly would raise a major dilemma for the Labour Party if it needed SNP support to form a government or remain in power. Ed Miliband could depend on Conservative support for a replacement of Trident, but if the issue became a red line in negotiations with the SNP he would have to decide whether his beliefs about the utility of nuclear weapons were sufficiently strong to give up an opportunity to become Prime Minister.
What this suggests is that Britain’s long nuclear experience, reflecting the beliefs, culture, and perceptions of identity of the political leadership, and especially the Prime Minister, might be severely challenged following the forthcoming election.