CentreForum says £25bn plans are a costly and illogical decision for armed forces squeezed by budget cuts
The UK's plans to spend more than £25bn on a new nuclear deterrent are "nonsensical" and should be scrapped because there is no foreseeable threat to the country, says a study published on Monday.
The paper, from CentreForum, an independent liberal thinktank, says the government is sleepwalking into taking a costly and illogical decision when the army, navy and air force are being squeezed by budget cuts.
It urges the immediate retirement of Trident with all the saved money being reinvested to upgrade the military's conventional weapons.
The 60-page study, Dropping the Bomb: A Post-Trident Future, is believed to reflect the views of many senior Lib Dems who are trying to force a debate on whether the UK still needs an independent nuclear deterrent.
The armed forces minister, Nick Harvey, is overseeing a review of alternatives to Trident. Due to report later this year, it is likely to challenge many of the assumptions that have made the Tories and Labour commit themselves to replacing the weapons system. A final decision on whether to replace Trident will take place in 2016.
CentreForum says the rationale that led the UK to seek an independent nuclear deterrent during the cold war no longer applies. Instead, it should move to "a nuclear threshold posture" – retaining some fissile material and engineering capability just in case there was ever "a substantial deterioration in the international climate" that led Britain to need a bomb within 12 months. The report makes clear this fallback position is unlikely to be needed.
It says: "There is no credible nuclear threat to the UK or her allies that will be deterred by a British nuclear weapons programme that is not already deterred by the United States' nuclear forces today or for the foreseeable future."
The paper's author, Toby Fenwick, says the UK only insisted on developing its own nuclear deterrent in the 1950s and 1960s because of "the unenunciated fear" that the US would not protect its allies in Europe, or that the Soviet leadership believed this was the case.
But the US has emphasised in "nuclear security guarantees" that it would respond if any Nato country were attacked. The report says: "As President [Obama] made clear, all Nato members have an explicit American nuclear security guarantee under Article V of the 1949 North Atlantic Treaty, noting, 'An attack on one is an attack on all. That is a promise for our time, and for all time'."
Though the paper accepts, for the sake of argument, that there are theoretical threats posed by Iran, Pakistan and North Korea, it says the UK is still protected under the US security umbrella. Retaining Trident would only provide an "incremental deterrent effect over and above that provided by the United States' nuclear arsenal".
CentreForum also dismisses those who claim the UK would lose its seat on the UN security council without a nuclear deterrent.
"Britain cannot lose its permanent seat without agreeing to do so … Linking possession of nuclear weapons as a sine qua non of holding security council permanent membership is both historically inaccurate and deeply unhelpful in the fight against nuclear proliferation … notions of national status have governed UK nuclear weapons policy. This is strategically myopic."
The paper also balks at the cost of replacing Trident, which is likely to put added stress on a defence budget that has been slashed in the past 18 months.
The government's plans to revitalise the military with new aircraft carriers and a range of other equipment – known as Future Force 2020 – are being put in peril, the paper insists.
"To spend a major part of the defence budget to protect against the distant possibility that a potential threat might arise on the outer edges of the UK's strategic interests, however, seems irrational, especially at the expense of conventional real-world capabilities."
It adds: "Spending more than £25bn in capital costs alone to replace Trident when it has no additional deterrent role to play in current or likely future UK security scenarios is inexplicable. Consequently, the UK should withdraw Trident from service immediately, and plough the savings into the UK's conventional forces to make the Future Force 2020 vision reality."
At the moment, Future Force 2020 is falling between two stools. "It was scaled back so that it is theoretically deliverable (making it too small to be operationally useful) but it remains unaffordable (making it unachievable)."
An MoD spokesman said: "The government is committed to maintaining a continuous submarine-based nuclear deterrent. Following a Trident value for money study, carried out as part of the strategic defence and security review, we are proceeding with the renewal of Trident.
"As part of the coalition agreement the Liberal Democrats will continue to explore the possibility of an alternative approach to delivering a credible nuclear deterrent. This work is led by the Cabinet Office and will report to the prime minister and deputy prime minister later this year."