'Positive Policy' - Defence: Part 3 of 4 - Cancelling Trident

Matthew Taylor (@MTPT) Posted by Matthew Taylor (@MTPT)
Friday, 5th March 2010

Of the UK's £36Bn annual defense budget, around 5% (about £2Bn) is spent on the UK's nuclear deterrent - a fleet of 4 Vanguard class ballistic missile submarines. Those submarines require either replacement, or expensive refitting, towards the end of this decade.



The need to replace the Vanguard class provides a useful natural break at which we can and should question both the need to maintain a nuclear deterrent, and the shape which it would take.



Should the UK maintain a nuclear deterrent at all? My answer is an unqualified 'yes'. The chances of a nuclear war breaking out are high today than at any time since the early 1960s. The return of democracy to Pakistan has (predictably) increased the instability in that state, and with it the risk of a war with India. On the Korean peninsula, preparations are already underway for the transition of power which must follow the death of Kim Jong Il. Israel's possession of nuclear weapons both drives Iranian desires for the same capability and creates a threat of a nuclear exchange which could well affect the states caught in the cross fire (or more accurately beneath the flight path).



I do not accept the argument that maintaining a nuclear deterrent is a pre-requisite for latter-day Great Power status, but I do consider that states which wish to be in the business of global power projection is well served by the possession of a nuclear deterrent. It is that projection of power which separates the UK from other non-super power states such as Japan and Germany.



But if we retain a nuclear deterrent, what form should it take? Crucially, how large should it be?



In the present Vanguard/Trident system, each sub can carry 16 Trident II D-5 missiles. Each missile carry up to eight nuclear warheads, each of which is five times more powerful than the bomb dropped on Hiroshima. But while those arguing for nuclear disarmament are fond of bandying about these numbers, they are misleading.



To begin with, the UK does not actually deploy four submarines; it deploys one. Under a system of continuous at sea deterrence (CASD), a fleet of four submarines is required to ensure that there is, at any time, one Vanguard submarine on station.



Secondly, the UK doesn't have 64 Trident missiles (one for each of the 16 missile tubes on each of the four submarines). We share of a pool of missile with the US Navy, from the Royal Navy is entitled to draw only 58. And that's before you count the missiles fired in tests over the years.



Finally, each missile carries no more than three warheads, and some carry only one. Aside from the fact that deploying every missile with its full complement of warheads would make it difficult to respond proportionately, the UK has (since 1998) chosen to limit the number of warheads in use.



Ironically, the deployment of Trident missiles represented a substantial increase in the size and potence of the UK's nuclear deterrent. The previous Polaris/Chevaline missiles had a much shorter range, and were capable of carrying fewer warheads. Crucially, they were also far less accurate.



Trident missiles are first strike weapons - they are accurate enough to be used to strike small hardened targets, such as missile silos. Polaris, by contrast, could not have been used in this role. It was a true deterrent - it could only be used in a "counter-value" role, inflicting devastating damage on enemy targets such as cities, rather than surgically striking enemy nuclear weapons.



It is difficult to justify the continued retention of a nuclear first strike capability. Without it, the UK's nuclear deterrent would remain a powerful deterrent, but cease to be potential weapons of war. Abandoning that requirement would substantially reduce the cost of any Trident replacement.



It is similarly difficult to justify the retention of the CASD approach. Although it may increase the deterrent effect, it does so at an entirely disproportionate cost, and it guards against a risk that is now substantially reduced, albeit not eliminated.



It is wrong to claim that the threat which the Trident missile was designed to counter has disappeared. The United States first deployed submarine launched ballistic missiles in 1960s because of fears about the vulnerability of their land based bombers; they developed the Trident missile in the 1980s because of fears about the vulnerability of land based missiles. The Russian missiles which prompted those latter fears remain in service. What has changed is the state of international relations: a major war between the super powers is now extremely unlikely to break out on brief notice.



Any substantial increase in international tensions would provide ample time to disperse our deterrent forces. It is simply no longer necessary to guard against a surprise nuclear attack which would remove our ability to retaliate. It remains important to guard against conventional attacks on our deterrent forces, but the costs of fixed security is a fraction of the costs of operating a submarine fleet.



Without the need to maintain a CASD posture, do we still need the submarines? The answer will depend on the form our deterrent forces take.



One option is to use a version of the Tomahawk cruise missile, which can be launched from the torpedo tube of an attack submarine. There would be no need to maintain dedicated ballistic missile submarines, and these missiles (developed for use in Europe in the 1980s) have already been developed. Some difficulties do exist: the United States had phased out its nuclear armed cruise missiles and we would have to develop our own warheads and potentially incur the additional costs of maintaining the missiles themselves.



Another credible option would be used conventional aircraft, carrying stand-off weapons. This represents a return to the approach which the UK government pursued in the early 1960s, seeking to equip its V-Bomber force with the Skybolt stand off missile. Then, as now, the range of the stand-off weapon was the principal weakness: against the air defences of a major state (such as Russia) either the carrier aircraft would have to expose itself to the risks of attack, or the missile itself might be shot down.


Either of these options - and they are only two of many potential ways in which a non-CASD deterrent could be deployed - involve the use of assets which can be used for other missions at other times. A move away from dedicated nuclear deterrent forces represents a substantial de-escalation.

At present, the United States is trying to show leadership over nuclear disarmament, with a view to using the five year review of the Non-Proliferation Treaty to achieve further reductions in nuclear arms. The UK can take a lead by conducting a "zero-base" review of its nuclear deterrent, and adopting a pragmatic policy as a result.


Ultimately, the substantial benefits (financial, political, and military) which will accrue from not replacing the Vanguard/Trident system like for like are too significant to pass up.