Somewhat to the surprise of most analysts, the British Government has decided to bring the question of nuclear weapon policy to the fore. This raises a series of questions. Why now? What will it be for? What are the costs? What is the best way forward?
The original decision on the Trident programme was announced on 15 July 1980 and the first boat was operational in 1994 with a planned life of 30 years. If any successor system were to take as long, a decision would be needed in 2010 for the first replacement in 2024. This could be extended by the phased changeover as the fourth Trident submarine does not go out of service until 2029. Of course the decision could be taken even later with life extension programmes, and also through a more rapid procurement. On the face of it , we can take some time coming to a decision.
Now state based threats are much reduced, it is difficult to outline a convincing scenario in which the UK deterrent plays a key part. However by the mid 2020s we might be in a very different world. A replacement system would have to counter possible challenges in the period 2025 to 2055. We have no crystal ball to tell us whether the threats will be from undeterrable non-state actors, or from a return to nationalism with nuclear-armed potential enemies. Nor can we know if the world will have become more peaceful, and nuclear weapons a historic irrelevance. Future uncertainty argues for leaving the decision as late as practical, if we are understand the strategic context.
Beyond the defence rationale, arguments about the importance of nuclear weapons to Britain's place in the world are often used. While such arguments may have had some credibility in the immediate post Second World War period, economic strength has become a more important factor in the age of globalisation. In any future reform of the United Nations, membership of the Security Council will not be decided on the basis of nuclear weapon ownership.
A more compelling foreign policy rationale for retaining our minimum deterrent force is that it gives the UK a significant card to play in future nuclear disarmament negotiations. All the nuclear powers have undertaken commitments under the Non Proliferation Treaty progressively to reduce their nuclear arsenals. The UK retains some leverage on this process while it has some weapons.
In any analysis of future defence capability, the question of costs must be a major consideration. Acquisition of Trident cost £12.52 bn at 1998 prices, with running costs of around £700m per year. Just as Trident procurement was described in 1982 as being comparable to the Tornado acquistion, we might expect a successor to bear comparison with Typhoon or aircraft carrier costs. It is unlikely that any nuclear certified system can be procured cheaply.
The related cost question will be whether the need for a particular system merits its share of the defence budget.. The effect on other conventional capabilities – the opportunity costs – are likely to be considerable. Again a lack of knowledge of our conventional needs and available resources so far in the future argues for commitment at the latest possible stage.
The relatively low running costs of Trident, coupled with high decommissioning costs, mean that there is no strong rationale for taking it out of service early. If some future international arms control opportunity arose, where we could improve our security, by reducing or eliminating our nuclear weapons, then it might be a different calculation. Such a possibility does not look likely in the near future.
Any radically new nuclear system, whether ballistic or cruise missile based, would involve significant development costs for the platform, missile and warhead. Such costs would put further pressure on a defence budget which is already finding it difficult to retain coherence. Nor is it clear that such systems could contribute to our security needs beyond deterring indeterminate future nuclear threats. The constraints of the NPT would cause further complications.
The most sensible answer is likely to be that we should keep the Trident system going with life extension programmes, when needed. We can have a useful public debate about the future of UK nuclear weapons, but we would be foolish to rush into decisions that are likely to prove costly and irrelevant.
Tim Garden is the Liberal Democrat Defence spokesman in the Lords, a former nuclear bomber pilot and the author of a book on nuclear strategy.