New RUSI Report on Trident Alternatives

Jul 28, 2010

By Oliver Bloom


The Royal United Services Institute, a British thinktank, has released a briefing, discussing alternatives to the current Trident renewal plans, already the subject of much controversy within the British Government. Written by Professor Malcolm Chalmers, the report explains what while
The Government is committed to maintaining an effective nuclear deterrent…the severe costs that Trident renewal could require… [make] a strong case for a re-examination of whether alternatives to current CASD [Continuous-At-Sea-Deterrence] policy could yield significant financial savings while continuing to meet this agreed objective. The fiscal situation facing the Ministry of Defence (MoD) is significantly worse than was assumed in 2006, when current renewal plans were drawn up by the previous government. And awareness of the opportunity costs of Trident renewal has grown as key production decisions draw nearer.
While the current Conservative-led British Government  remains committed to the Trident replacement, Defense Secretary Liam Fox recently spoke of the Government’s willingness to consider alternatives within the Trident replacement program (increasing operational risk, reduce submarines numbers, etc.) as a means to reduce costs. In light of the Government’s commitment, the viability of CASD and the bleak fiscal outlook for Britain, Chalmers offers four possible alternatives that, while still involving a strategic nuclear deterrent, may be less costly but still effective. 
The report urges a reexamination of Trident renewal in light of two realities: first, that
there is now a stark gap between the assumptions on which planning for the UK’s conventional and nuclear forces, respectively, are based.
And second, that the fiscal circumstances are changing, particularly as a result of tighter fiscal circumstances, the expenses associated with the CASD requirement, and the Treasury’s insistence that the Ministry of Defense fund Trident within its core budget (something that hasn’t previously been the case).
On the first point, the report notes a widening gap in British strategic thinking between conventional and nuclear force planning. As Chalmers explains
Discussion of options for conventional capability in the current [Strategic Defense and Security Review] is based on the assumption that a significant threat of attack on the UK homeland by other states will not re-emerge without an extended period of strategic warning.
In contrast, the commitment to maintain a nuclear armed missile submarine on patrol at all times has remained largely unchanged since the 1960’s, when a surprise attack on Western Europe by the Soviet Union was a central driver for UK force planning.
On the second point, Chalmers explains that
the inclusion of Trident renewal in the core budget, on current plans, could require the MoD to plan for a further significant real reduction in annual conventional spending by 2020,over and above any reduction that the Spending Review decides to make over the next four years.
In light of these questions, Chalmers examines four possible alternatives: a ‘normally-CASD’ submarine force, a ‘CASD-Capable’ submarine force, a ‘dual-capable’ submarine force, and a non-deployed force. He suggests that while
All four options would allow the UK to maintain a strategic nuclear deterrent. Depending on the assumptions made, each option might also allow some significant delays in the timing of Trident renewal, and/or in the number of new submarines that are required.
The “normally-CASD” submarine force would involve the Ministry of Defense accepting greater operational risk of possible interruptions in CASD in light of certain contingencies (at-sea collisions, technical failures, loch exit blockage), and therefore abandon the current policy of keeping a second submarine on short notice for patrol in case of problems with the primary patrol boat. As Chalmers explains, such a change would facilitate a reduction in future fleet size to three boats while simultaneously delaying the successor program for up to five years. 
On the second option, the ‘CASD-capable’ submarine force, Chalmers explains that
the attempt to maintain CASD in normal circumstances would be abandoned, and replaced by an assumption that it would only be necessary to have the ability to reconstitute CASD if required, and then to maintain it for a significant (though not indefinite) period. The timescale for reconstitution would, in turn, be determined by an assessment of the shortest period over which a new strategic threat to the UK homeland could re-emerge.
In light of the changed posture, Chalmers imagines that the successor fleet could be reduced to two boats and delivery could be delayed up to ten years, at the expense of longer periods when a boat is not on patrol. 
The third option, the ‘dual-capable’ submarine force, imagines new submarines with only four missile tubes (rather than the twelve planned for the Vanguard replacement), that would facilitate the merger of the attack and ballistic missile submarines into ‘dual-purpose’ boats. Chalmers notes that
Such an arrangement could, in time, combine increased survivability for the nuclear force while also holding out the possibility of further reductions in the size and readiness of the nuclear deterrent. It might also provide a more consistent flow of submarine construction work than alternative options [at the expensive of lower medium-term savings].
Lastly, and most drastically, Chalmers examines the option of a non-deployed strategic force that would base the UK’s nuclear strategy around the idea of guaranteed, but not prompt, nuclear retaliation. Such an option would emphasize survivability of the force but not prompt retaliation, and involve a variety of possible response delivery systems besides submarine launched ballistic missiles. As Chalmers explains,
By removing the requirement for deployed sea-based forces, substantial financial savings could be generated, although allowance would have to be made for additional hardened infrastructure costs.
He does quickly note, however,
[s]uch an option is probably too radical to be politically acceptable at present, and may remain so until other nuclear-armed states (and the US and Russia in particular) have taken substantial steps of their own to reduce deployed force levels. It should not be ruled out as a longer-term option, however, perhaps as part of a multilateral agreement to move to lower states of nuclear readiness.
In addition to his analysis of the present problems and his four proposed alternatives, Chalmers adds two side notes that are particularly worthwhile in discussion of any nuclear deterrent. First, he explores ‘the costs of protection,” in the case of Trident replacement, the
requirement for the conventional SSBN protection capabilities that are maintained in order to protect the deterrent against attack by the armed forces of other states [Britain’s ASW capability, for example].
While it is difficult to assign direct cost levels to many of these dual-role systems, it is nevertheless valuable to note how changes in force posture can open the door to a variety of other possible cuts, well beyond the weapon and its delivery system/launch platform.
Second, Chalmers challenges the assumption that delays in a submarine replacement program could result in gaps in submarine orders that may threaten the future expertise of the industry and possibly cause the loss of irreplaceable skilled personnel. In particular, he doubts the rigidity of the labor market and also imagines that
a range of other options – both for construction management and construction itself- could become available were procurement to be postponed [particularly in light of likely cuts in U.S. submarine replacement programs].
Malcolm Chalmers’ RUSI report is not the first to question the future of Trident, but it approaches the debate in a novel way—challenging the assumption that Britain needs a continuous-at-sea-deterrent. While his report is brief, Chalmers certainly sheds doubt on that assumption and draws attention to the growing divergence between Britain’s nuclear force planning and its conventional planning. If conventional planning is being retooled around 21st century threats, it certainly makes sense to examine why nuclear planning isn’t as well. 
If the fundamental assumption about the necessity of CASD changes, then a whole host of other options are suddenly on the table, without quite the radical retooling of the force that other analysts have examined and questioned. Chalmers’ proposals may be the necessary middle ground between proponents of a submarine-based nuclear deterrent and those opponents questioning its cost and necessity. 
Given the cost of the Trident replacement program, and the offsetting conventional cuts, the British government needs to make a convincing case that continuous-at-sea-deterrence is fundamentally necessary for Britain’s security before the country pursues the vast expenditure of a future ballistic missile submarine. So far, it has failed in that regard. The Liberal Democrats, who made an election issue of Trident renewal, should push the government to at the very least address these questions, so British citizens can know that the Government explored all options and questioned all assumptions before it embraced such a costly defense expenditure.


Trident options

This draws on a much more substantial report from the Nuclear-Armed Britain programme at the University of Bradford's Department of Peace Studies on "Continuity/Change: Rethinking Options for Trident Replacement", available at