Trident Alternatives Review sets out options to 'like-for-like' replacement

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The long-awaited Trident Alternatives Review, published by the Cabinet Office, has concluded that there are credible alternatives to replacing the UK's current Trident nuclear weapons system although these would cost more and might not guarantee the same “degree of resilience” as the government's preferred 'like-for-like' replacement option.

The review considered a variety of nuclear weapon systems and postures as an alternative to 'like-for-like' replacement, and investigated their feasibility and how they might be delivered, although it made no recommendations for or against any particular system.

Large aircraft, fast jets, surface ships, and three types of submarine - different designs of 'hunter-killer' submarines, ballistic missile submarines, and a submarine design that could fire either ballistic missiles or cruise missiles – were considered as potential future platforms for the UK's nuclear weapons.

As well as different launch platforms, the review also considered a range of different postures for the deployment of nuclear weapons.  Five different options are presented in the report, ranging from the current “continuous at sea deterrence” posture to lower degrees of nuclear readiness.

Although much of the analysis carried out by civil servants remains unpublished, the Trident Alternatives Review nevertheless represents the most detailed assessment of nuclear policy options ever published by the UK government, and provides a far greater depth of insight into government thinking than was published in the 2006 White Paper on Trident replacement.

The review defined the requirement for the UK's nuclear weapons as “a minimum nuclear deterrent capability that, during a crisis, is able to deliver at short notice a nuclear strike against a range of targets at an appropriate scale and with very high confidence,” and then assessed how effectively a range of various alternative systems might meet this requirement.  It also considered the contribution that the UK's nuclear weapons make to NATO's nuclear doctrine.

The review describes design and development of a new warhead as the “critical challenge” to developing an alternative platform to Trident, such as a nuclear cruise missile or air-launched bomb, as the UK's current warhead programme is heavily focused on Trident.  Different warhead designs would be needed for ballistic missiles, for cruise missiles and for free-fall bombs, making a considerable difference to the costs, timing and technical risks for each of the different systems

The review estimates that it would take 17 years to develop a new ballistic missile-based warhead to replace the current Trident warhead, and even longer for an alternative system – possibly up to 24 years for a cruise-missile based system.   Development of a new Trident warhead would be expected to cost around £4 billion, whereas development of a new warhead for a cruise missile or free-fall bomb would cost around £8-10 billion.

In the absence of an equivalent US warhead programme, the UK would have to invest significantly in developing non-nuclear warhead components.  According to civil servants, this would result in a warhead development programme which would be longer than the remaining in-service life of the current Vanguard class submarines, raising questions about the transition period between the two systems.

Unlike non-Trident options, the cost driver for Trident missile options is the construction of new submarines.  In terms of whole-life costs, a three-submarine Trident fleet was considered to be the cheapest option investigated in the review, with hunter-killer submarine and air-launched options assessed as considerably more expensive.

The Review glosses over broader issues relating to the international impact that a move to a new posture or platform might have, stating that “the precise short-term impact of how any change is received would depend on the type of new system/posture and, crucially, on whether it represented a diminution in the UK‟s associated level of deterrent ambition”.  Legal issues are side-stepped with a statement that the UK takes the position that pursuit of a renewal of Trident or a new system does not breach the Non-Proliferation Treaty.

The review concludes that “there are alternatives to Trident that would enable the UK to be capable of inflicting significant damage such that most potential adversaries around the world would be deterred”, and that the UK could adopt alternative non-continuous deployment postures for its nuclear weapons, although these would not offer the “same degree of resilience” as the current posture of continuous deployment of nuclear weapons.  A decision on whether to operate submarines in a non-continuous posture would depend upon the level of political confidence that there would be no sudden unexpected attack on the UK and that back-to-back nuclear patrols could recommence during a crisis.

The terms of reference of the Cabinet Office review did not cover a non-nuclear option, but the Campaign for Nuclear Disarmament has recently published 'The Real Alternative' - a review outlining the case for abolishing the UK's nuclear weapon capability.

The Trident Alternatives Review commenced in May 2011, when the government announced that an 'initial gate' decision had been made to develop new ballistic missile submarines as replacements for the current Vanguard class Trident submarines, in response to a commitment from the Coalition government to allow the Liberal Democrats to make the case for alternatives to 'like-for-like' replacement.

The options and conclusions outlined in the Trident Alternatives Review are now expected to set the scene for debate and discussion on political party policies on nuclear weapons before the 2015 General Election, particularly in the Labour and Liberal Democrat parties.