The coalition is understandably hesitant about committing to the cost of replacement - but it does affect our deterrent credibility.
By Dr Lee Willett, Head, Maritime Studies Programme, RUSI
This article was first published in the Guardian's Comment is Free website
Britain is still a global power. It has worldwide interests (including overseas territories and resource dependencies) and global responsibilities it continues to uphold. Given the fact that nuclear weapons exist and large, upgraded arsenals are retained by several powers with whom the UK does not have any kind of alliance, it is easy to perceive circumstances in which the Britain might need to use the political leverage of its nuclear deterrent. While there may not appear at the moment to be an obvious, direct threat to UK territory, its global dependencies and reliances make it vulnerable to crises elsewhere. And even if Britain found a way to walk away from these dependencies, a deterrent would still be needed to defend the islands.
Existing and emerging nuclear powers provide risks that must be mitigated against, and other states could also seek and gain a nuclear weapons capability. If nothing else, the cold war taught the world that nuclear weapons have significant political leverage.
In the 2006 white paper, the Labour government explicitly denied that the possession of a nuclear deterrent had anything to do with generating global political influence.
Yet later, as prime minister, Gordon Brown showed exactly how nuclear weapons do have influence when offering to trade the UK's nuclear deterrent in the context of multilateral global disarmament. This influence remains so important that, despite fundamental changes in the way the world operates since the dawn of the nuclear age, the five permanent members of the United Nations security council remain the first five nuclear powers. If Britain was to stand down its deterrent, questions would be raised about its continuing right to retain its permanent seat faster than one could say "India".
The UK is the only nuclear power to deploy its deterrent in a single system. With a minimum force level, a submarine-based ballistic missile is the only credible option. (A cruise missile would have insufficient range and speed to provide a viable alternative, and in any case building a wholly new programme from scratch independently would cost more than the current system.) Discussions of numbers of submarines and deterrent postures are something of a red herring. The warheads are, after all, the nuclear weapon: everything else (submarines, missiles, infrastructure) just delivers them. William Hague, the foreign secretary, has already broken the mould by publicly stating the number of warheads the UK stockpiles. The current operational posture is for the UK to deploy up to 48 warheads on the patrol submarine. The stockpile is large enough to generate 48 warheads for the patrol boat. Yet the scenario of the UK firing such a large number - despite the strategic logic being that this figure allows the UK to address all potential deterrent circumstances - seems so unlikely that there may be scope to reduce warheads, if not on the patrol boat then from the stockpile.
Today's news that the government is considering delaying the building of the replacement submarines by extending the life of the current boats is not new - the possibility was discussed actively during the 2006/2007 white paper debate. Given the UK's financial circumstances and the coalition's agreement to examine the deterrent's value for money, it was inevitable that the government would be examining all options within thestrategic defence and security review. With the Liberal Democrat party conference looming, deferring the final decision until the next parliament buys the coalition partners political kudos and breathing space up to the next election. The deterrent is, as it always has been, a political tool, and this latest story is just another political twist in its life.
However, if the coalition government hopes that by deferring a final decision on the building of four new submarines will kick the debate itself into the long grass, it likely will find itself mistaken. One surety in the debate has been that every time a government has tried to avoid discussing the issue, this has only reignited the debate.
All this discussion does have one clear consequence, however. It creates doubt that Britain is committed to its deterrent tomorrow, thus weakening deterrent credibility today.