Trident ballistic missile submarine

Defence of the Nation – An open letter to the incoming Prime Minister 2015

Dear Prime Minister

Trident Submarine Renewal

As you resume or take on office, you will recognise one of the heaviest and most important burdens on your desk will be your responsibility for Britain’s independent nuclear deterrent. That deterrent exists, as you will know, not as a military weapon but a political one whose very purpose is for it never to be used in anger. It is there to deter aggression against this country and our allies and to counter any nuclear blackmail which would threaten Britain’s essential interests or survival . It is committed to NATO and with the French and American deterrents plays a crucial and successful part in the defence of the Alliance.

You and your Defence Secretary have responsibility for the operation, targeting and conduct of the submarines carrying the Trident D5 missiles constantly on patrol. You will also, importantly, be responsible for the decision next year whether or not to go ahead with the ‘Main Gate’ decision on triggering the building of 4 new submarines necessary to continue the deterrent and replace the Vanguard submarines soon coming to the end of their lives.

The ‘Main Gate’ decision was postponed to 2016 by the former Coalition government but, due to the age and fragility of the existing fleet, you will be all too aware that the decision cannot be delayed further. A decision not to go ahead would effectively end Britain’s nuclear deterrent since no replacement submarine would be available. It can also be argued that patrolling would have to stop immediately since the deterrent’s effectiveness and credibility in the eyes of both adversaries and allies would be shredded.

It is supremely important to recognize that it is inconceivable that Britain could in future resume its deterrent if there was a negative decision at the ‘Main Gate’. Such a decision not to proceed with main gate pretty well immediately would therefore be irreversible.

Therefore, in the light of the grave importance of the decision you have to make, you, your ministers and officials may find it helpful to bear in mind the following points:

Opinion of the Political Parties

You will be aware that both the Conservative and Labour Parties are publicly committed to the deterrent and to Continuous at Sea Deterrence (CASD). This involves one submarine being on patrol at any time, whereby it is undetectable and invulnerable . The Liberal Democrat Party has some reservations about word ‘continuous’ but Sir Nick Harvey, former Liberal Democrat Minister for the Armed Forces, has stated that two submarines should be ordered anyway. The Scottish National Party is publicly committed to abandoning the successor to the Vanguard class submarines but it should be noted that its Party Conference embraced the idea of an independent Scotland being in NATO. NATO’s Strategic Concept explicitly “commits NATO to the goal of creating the conditions for a world without nuclear weapons – but reconfirms that, as long as there are nuclear weapons in the world, NATO will remain a nuclear alliance.” UKIP supports CASD, as do the Ulster Unionists, while the Welsh Nationalists and the Green Party oppose nuclear deterrence.

Public Opionion

You should note that serious tests of public opinion consistently show that the British public back the nuclear deterrent. For example the House of Commons Select Committee on Public Administration, using the respected YouGov organisation, conducted a survey (April 2013) asking the question;

If the UK Government decided there was no cheaper alternative for an effective nuclear weapons system, and you had to choose between keeping the current nuclear weapons system Or giving up nuclear weapons altogether which of the following statements would come closest to your view?

The United Kingdom should order four new submarines to maintain its nuclear weapons system 57%

The United Kingdom should give up nuclear weapons altogether 27%

Don’t know 17%

Studies on the Detterent

You will want to be reminded of the thorough studies which have taken place during the last Parliament on the necessity for, and the method of guaranteeing, the British independent deterrent

The Trident Alternatives Report

Arising from Liberal Democrat demands, and enshrined in the Coalition Agreement, a full study of the alternatives to Trident and CASD was set up by the Cabinet Office at the request of the MOD. . It published its report on 16 July 2013 and submitted the findings to Rt Hon Danny Alexander MP, Chief Secretary to the Treasury. It exhaustively reviewed all the alternative systems to Continuous At Sea Deterrence.

It concluded emphatically: “The highest level of assurance the UK can attain with a single deterrent system is provided by SSBN (Ballistic Missile submarines) operating under continuous at sea deterrence posture.”

In addition, it said; “None of these alternative systems and postures offers the same degree of resilience as the current posture of Continuous At Sea Deterrence, nor could they guarantee a prompt response in all circumstances.”

The BASIC Trident Commission

Even before the Trident Alternatives Review had reported another review had been initiated, supported by the NGO BASIC (British American Security Information Council) entitled ‘An independent, cross-party inquiry to examine UK nuclear weapons policy’. BASIC describes itself as ‘a small but influential think-tank with one very big idea: we want a world free from the threat of nuclear weapons’. The members of their Commission were hand-picked and very distinguished and represented different viewpoints on deterrence.

After exhaustively examining the case for a British nuclear deterrent and CASD, the Commission convincingly concluded:

“Nevertheless they (successive British governments), have not considered it prudent to disarm the UK’s nuclear arsenal given the nuclear danger that could yet resurface, and given the limited benefit to reducing global nuclear dangers such a step would have. We agree.”

They went further: “The Trident SSBN (Ballistic Missile Submarines) system meets the criteria of credibility, scale, survivability, reach and readiness. Whilst the Commission is not in a position to interrogate the information and assumptions underpinning the (Trident Alternatives) Review, we are opposed to proposals to develop alternative platforms and delivery systems, with new warheads, simply on the basis of possible but speculative cost savings.”

The Report of the BASIC Commission was published in July 2014.

Alternative Systems to Trident CASD

Both Reports make it clear that the various alternatives to Trident based Continuous At Sea Deterrence have serious weaknesses and are rejected.

These include using Cruise Missiles on Astute Class attack submarines (Weaknesses; retro-fitting and redesigning the current models, facing a problem of distances to target, the complexity and cost of building a new warhead and a brand new missile and the vulnerability of any such missile).

Another option proposed is using free-fall bombs (abandoned in the UK by the 1998 Strategic Defence Review) to be carried by adapted F35 Joint Strike Fighters flying from very expensively modified aircraft carriers. ( Weaknesses; The vulnerability of the platforms in a nuclear role, the cost of adapting the Carriers, the cost of inventing a new warhead for the American bomb, the inadequate reach of the F35 system for this mission, and the unquantified cost of the project).

The other alternative floated is non-continuous patrolling by Trident submarines. Whilst superficially attractive and speculatively cost-reducing, the Trident Alternatives Review ruled it out on good practical grounds. It could escalate a crisis if submarines were seen to be deployed, the training of crews would degrade compromising the surety of operations, access seaways could be blocked by an adversary before deployment, and the ambiguity inherent in deployment might alarm an opponent.

The Trident Alternatives Review is definitive in its opinion on alternatives.;

“The costs of delivering an alternative system could theoretically have been cheaper than procuring a like-for-like renewal of Trident were it not for timing and the fact that the deterrent infrastructure is finely tuned to support a submarine-based Trident system. In particular, the time it would take to develop a new warhead (itself a costly and high risk exercise) is judged to be longer than the current Vanguard-class submarines can be safely operated. Bridging the resulting gap in deterrence capability would involve procuring two successor SSBNs so that the Trident-based deterrent remain available until at least 2040. Doing that at the same time as investing in the development of a new warhead, new missile, new platform and new infrastructure, means that transitioning to any of the realistic alternative systems is now more expensive than the 3 or 4-boat Successor SSBN fleet.”

Beware of Unsupported and Misleading Assertions

As you contemplate the decision on ‘Main Gate’, a blizzard of arguments will seek to influence your government’s decision. These will largely come from those who have been frustrated by the definitive conclusions of the recent Reviews. Examples follow.

Trident Submarine Successor will stimulate proliferation? On the contrary, the deep reductions in Britain’s deterrent made by successive governments have produced no reciprocation from other nuclear weapon or aspiring nuclear weapon powers. Britain now has reduced to only one system, made dramatic reductions in the number of missiles and warheads per submarine combined with de-targetting and warning times extensions. This, and severe reductions by the US and France, have been accompanied by increases in the nuclear capabilities of China, India, Pakistan and North Korea. Russia too has embarked on a programme to modernise its nuclear forces and has made threatening statements about their use.

There is a need for yet another Review because the others had ‘erroneous assumptions’? There have now been Reviews of the need for the deterrent in 2006, 2010, 2013, and 2014. All have been conclusive. This demand is merely another attempt to get the answer which has been repeatedly rejected.

Only the USA , France and the UK have Continuous At Sea Deterrence? The fact is that both Russia and China have Inter Continental Ballistic Missiles on high alert (the UK does not) and both are moving to CASD.

Renewing Trident would frustrate negotiations ongoing in the Nuclear Non Proliferation Treaty Review Conference? You will note, in this context, what the BASIC Trident Commission said, “Though possession is not legally required for nuclear weapons status under the NPT (defined in historical terms), it is doubtful that the UK would retain continuing influence on the thinking or process of nuclear negotiations if it ceased all its nuclear weapon activities.”

Trident expenditure is a crippling cost at this time of austerity? Critics of the Trident programme invent ever larger fictional figures for the whole life costs of the renewal project. In fact the total cost throughout a life of up to 2060 would be an average of around £2billion a year (taking a lifetime estimate of £80billion). In comparison the British National Health Service costs £2.5billion A WEEK.

The nuclear deterrent does not address new threats such as terrorism, hybrid and cyber attacks and jihadi individuals? Correct, but irrelevant. Other deterrents and capabilities are needed for these threats but only the nuclear deterrent can deter nuclear blackmail and nuclear armed aggressor states including any state which were to consider providing nuclear weapons to terrorist organizations.

Abandoning the deterrent by not ordering new Trident submarines would save a vast amount of money at a time of limited public spending and a squeezed Defence budget? This facile argument deployed to justify expenditure on other armed forces or social programmes ignores the incontrovertible fact that cancellation is not a cost-free option. Decommissioning deterrent submarines and the broad infrastructure supporting the system would produce very substantial and recurring costs from the moment the decision not to proceed is taken.


Prime Minister, the decision on ‘Main Gate’ next year will be one of the most important ones to be taken by this generation of political leaders. Its consequences will be felt inside and outside of the country for many years to come. Allies and adversaries both current and potential will have an interest in the outcome.

Please also remember this. The decision ahead of you will be irrevocable; it is inconceivable, whatever grave threat emerges in the future, that the deterrent could be reconstituted if abandoned now or left to wither.

It is impossible to tell what threats may emerge over the more than thirty years of the new generation of submarines and therefore how safe future generations will be. To abandon Trident now and for good in the hope that no threat will emerge over that lengthy period would be take an enormous gamble on behalf of generations yet to be born.

You might, in this context, reflect on the wise words in the BASIC Trident Commission,

‘Based on the two key specific considerations, namely national security concerns and responsibility to the Alliance, the Commission has come to the unanimous conclusion that the UK should retain and deploy a nuclear arsenal, with a number of caveats expressed below. Most notably, it remains crucial that the UK show keen regard for its position in the international community and for the shared responsibility to achieve progress in global nuclear disarmament.’

The United Kingdom has made reductions in its nuclear arsenal proportionately greater than any other nuclear weapons power. That has represented a huge contribution towards nuclear disarmament. We should stand ready to do more – but only if it can be conclusively shown that it does not compromise minimum levels of nuclear deterrence and would simultaneously contribute to multilateral global disarmament.

In an uncertain world where some powers are now displaying a worrying faith in nuclear weapons as an instrument of policy and influence, it would be, in our opinion, irresponsible folly to abandon Britain’s own independent deterrent. That fact indeed encapsulates the enormity of the decision which the Main Gate decision will mean for the security and ultimately the survival of our nation.

Prime Minister, we strongly urge you to bear the above in mind as you lead Parliament in the debate on ‘Main Gate’.

Lord Robertson of Port Ellen
former UK Secretary of State for Defence and Secretary General of NATO

Lord Hutton of Furness
former Secretary of State for Defence

Lord Hennessy of Nympsfield
Historian and Broadcaster

Lord Moonie of Benochy 
former Parliamentary Under Secretary of State Armed Forces

General Lord Richards of Herstmonceux
former Chief of the Defence Staff

Admiral of the Fleet Lord Boyce
former Chief of the Defence Staff

Marshal of the Royal Air Force Lord Stirrup of Marylebone
former Chief of the Defence Staff

Admiral Lord West of Spithead
former First Sea Lord and Minister for Security

Admiral Sir Jonathon Band
former First Sea Lord

Admiral Sir Mark Stanhope
former First Sea Lord

General Sir Mike Jackson
former Chief of the General Staff

Sir David Omand
former Director GCHQ and Permanent Secretary Home Office

Sir Kevin Tebbit
former Permanent Secretary MOD

Sir Keith O’Nions
former Chief Scientific Advisor MOD

Tom McKane
former Policy Director MOD

Professor Paul Cornish
RAND Europe

Julian Lewis
Bernard Jenkin 
John Woodcock

Commodore Tim Hare
former Director Nuclear Policy MOD


First published in the Times 29 April 2015