This autumn has seen the Labour government and the Conservative opposition begin to position themselves on the issue of public spending cuts. In the search for cuts outside the key areas of health and education, people not belonging to either of the main parties have identified one area in which the government could easily reduce its commitments: the upgrading of the nuclear deterrent. A decision was reached in 2006 to replace the ageing fleet of submarines which carry the Trident missile system when they reach the end of their working life in the early 2020s. When the plan was announced in 2006 its cost was estimated at £15 billion, but recent estimates have ranged from £40 to 70 billion. The Prime Minister has announced plans to reduce the nuclear submarine fleet from four to three in the 2020s - but large sums will nevertheless be devoted to Trident replacement over the coming years, at a time when other areas of the budget will be coming under increased pressure.
At a time when British forces in Afghanistan appear to be short of resources, many see the commitment to a new nuclear deterrent as wrong
Alongside the economic case for cancelling the upgrade, its strategic worth has also been questioned. At a time when British forces in Afghanistan appear to be short of manpower and equipment, many see the commitment to a new nuclear deterrent as wrong-headed. An Institute of Public Policy Research commission, co-chaired by Lord Robertson (ex-Defence Secretary and Secretary-General of NATO) and Lord Ashdown, concluded in June 2009 that ways of delaying the replacement of Trident should be explored - instead using the money to provide more flexible responses to the global security threats that confront the UK on a day-to-day basis.
The economic and military requirements of the day suggest that scrapping or delaying the upgrade of Trident could save enormous sums, some of which could be devoted to improving British capabilities in the face of security threats.
According to a recent Guardian/ICM opinion poll, such a decision would be popular, with only 42 per cent of those questioned backing replacement. Yet despite these arguments, the government has specifically excluded Trident from the forthcoming Strategic Defence Review, and the Conservatives say too that they are committed to the upgrade.
This is hardly the first time that the decision to replace or upgrade the deterrent has been called into question. In fact, whenever the UK has updated its nuclear weapons system since the early 1960s there have been questions asked about its economic and military worth. The rationales for maintaining the deterrent at these times can give us some insight into the firm position of the Labour and Conservative Party alike.
The main rationale is the unpredictability of UK's future security requirements. A decision is being taken now to replace the submarines in the 2020s and provide a deterrent into the 2040s. Much the same happened when debating whether to improve the Polaris system in the 1970s, or when originally purchasing Trident in the 1980s. As it is impossible to second-guess future requirements it has always been deemed safest to possess, in military historian Sir Michael Howard's words, 'every club in the bag'. In addition to the long lead times involved, the widespread assumption that the UK would never be able to resurrect its capability once abandoned has left politicians reluctant to leave their future selves unarmed.
Another consideration for pressing ahead with the upgrade is the diplomatic advantages that possessing nuclear weapons is seen to provide. It has been widely assumed that the deterrent helps preserve the UK a permanent place on the United Nations Security Council. It also ensures UK's position in discussions of disarmament and non-proliferation. Aneurin Bevan in 1957 famously castigated the supporters of unilateral disarmament for wanting to send him (as Shadow Foreign Secretary) 'naked into the conference chamber' - only if the UK possessed weapons could he help bring about multilateral disarmament.
The concrete diplomatic impact of retaining the deterrent is impossible to gauge, but the assumption that these weapons bolster UK's standing in the world has played an important role in ensuring that they remain. As Winston Churchill put it, 'it's the price we pay for sitting at the top table'. The desire to remain at the 'top table' and safeguard against strategic uncertainty helps to explain why the government is so enamoured with Trident replacement when others cannot see the appeal.