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L'avenir des forces nucléaires françaises

12 juillet 2012 : L'avenir des forces nucléaires françaises ( rapport d'information )

LA POSITION BRITANNIQUE (document fournie par l'ambassade du Royaume-Uni à Paris)


· HMG believes that nuclear weapons remain a necessary element of the capability we need to deter threats from others possessing nuclear weapons.

· The UK would only use its nuclear weapons in extreme circumstances of self-defence, and would not use its weapons contrary to international law.

UK deterrence policy comprises five key principles:

· Preventing nuclear attack. The UK's nuclear weapons are not designed for military use during conflict but instead to deter and prevent nuclear blackmail and acts of aggression against our vital interests that cannot be countered by other means.

· The UK will retain only the minimum amount of destructive power required to achieve our deterrence objectives. This is known as «minimum deterrence».

· We deliberately maintain ambiguity about precisely when, how and at what scale we would contemplate use of our nuclear deterrent. We will not simplify the calculations of a potential aggressor by defining more precisely the circumstances in which we might consider the use of our nuclear capabilities - i.e. we do not define what we consider to be our vital interests. Hence, we will not rule in or out the first use of nuclear weapons.

· The UK's nuclear deterrent supports collective security through NATO for the Euro-Atlantic area.

· An independent centre of nuclear decision-making enhances the overall deterrent effect of allied nuclear forces. Separately controlled but mutually supporting nuclear forces create an enhanced overall deterrent effect. The UK deterrent is operationally independent, and the UK does not require US authorisation to use its deterrent.

· All the United Kingdom's Trident missiles have been de-targeted since 1994. Only one Trident submarine is on deterrent patrol at any one time and that submarine is normally on several days `notice to fire' and its missiles are not targeted at any specific country. The missiles can be targeted in sufficient time to meet any foreseeable requirement


There are three potential threats identified in the 2006 White Paper:

· The re-emergence of a major nuclear threat.

· A threat from an emerging nuclear state.

· State-sponsored nuclear terrorism.


· The UK does not currently identify an enemy with both a nuclear capability and the intent to use it against our vital interests.

· However, significant nuclear capabilities and nuclear risks remain. There are still substantial nuclear arsenals; the number of nuclear-armed states has increased, not decreased; and there is a significant risk of new nuclear-armed states emerging.

· We cannot dismiss the possibility that a major direct threat to the UK might re-emerge - a state's intent in relation to the use of its capabilities could change relatively quickly, and while we will continue to work internationally to enhance mutual trust and security, we cannot rule out a major shift in the international security situation which would put us under grave threat (SDSR).

· It is the ultimate guarantee of our security and sovereignty and a necessary insurance in an uncertain world.


· The UK has long been clear that we would only consider using our nuclear weapons in extreme circumstances of self defence, including the defence of our NATO Allies, and we remain deliberately ambiguous about precisely when, how and at what scale we would contemplate their use.

· The UK remains committed to the long term goal of a world without nuclear weapons.

· We will continue to work to control proliferation and to make progress on multilateral disarmament, to build trust and confidence between nuclear and non-nuclear weapon states, and to take tangible steps towards a safer and more stable world where countries with nuclear weapons feel able to relinquish them.


· We are now able to give an assurance that the UK will not use or threaten to use nuclear weapons against non-nuclear weapon states parties to the NPT. In giving this assurance, we emphasise the need for universal adherence to and compliance with the NPT, and note that this assurance would not apply to any state in material breach of those non-proliferation obligations.

· We also note that while there is currently no direct threat to the UK or its vital interests from states developing capabilities in other weapons of mass destruction, for example chemical and biological, we reserve the right to review this assurance if the future threat, development and proliferation of these weapons make it necessary.


The SDSR announced reductions in the size of the nuclear deterrent as a result of HMG's reassessment of the minimum necessary requirements for credible deterrence. It was decided to:

· reduce the number of warheads onboard each submarine from 48 to 40

· reduce our requirement for operationally available warheads from fewer than 160 to no

· more than 120

· reduce our overall nuclear weapon stockpile to no more than 180

· reduce the number of operational missiles on each submarine to no more than eight.

These changes will enable the UK to reduce its overall nuclear warhead stockpile ceiling from not more than 225 in May 2010 to not more than 180 by the mid 2020s.


· HMG's preference is for submarine based ballistic missile deterrent force, providing Continuous At Sea Deterrence (CASD).

· CASD is the backbone of our deterrent posture. A deterrent system must be able to function irrespective of any pre-emptive action that might be taken by a potential aggressor.

·  Our preference to achieve this is for an invulnerable and undetectable system that allows for the minimum scale necessary, and which is currently expressed by the deterrent patrols of our Vanguard class submarines.

· Submarines are the most cost effective way of delivering a credible deterrent. Their invulnerability to detection makes it impossible for a potential aggressor to launch a pre-emptive strike.

· Trying to achieve this level of capability with other platforms is either not possible or requires an enormous number of platforms.


· Neither the NPT nor the ICJ Advisory Opinion of July 1996 set out any timetable for the fulfilment of NPT Article VI nor preclude the UK from maintaining its existing capabilities.

· It has sometimes been suggested that International Court of Justice has ruled that threat or use of nuclear weapons is illegal. The International Court of Justice published its Advisory Opinion on the legality of threat or use of nuclear weapons on 8 July 1996. The Court confirmed that the use, or threat of use, of nuclear weapons is subject to the law of armed conflict. The Court did not conclude that such use would necessarily be unlawful.

· The ICJ concluded that legality can only be determined in the light of the specific circumstances applying when such use is being contemplated. The legality of any such use would depend upon the circumstances and the application of the general rules of international law, including those regulating the use of force and the conduct of hostilities.

· We remain confident that the United Kingdom's minimum nuclear deterrent is entirely consistent with international law. We would not use our weapons, whether conventional or nuclear, contrary to international law.


· The Government supports working towards a world without nuclear weapons when the time is right. While we are not there yet, there is clearly a renewed momentum with this work and the UK continues to demonstrate its NPT obligations in this regard.

· The positive outcome of the May 2010 NPT Review Conference and the Action Plan that emerged from this conference is an important step along this road. The Action Plan includes a number of recommendations for follow-on actions across all three pillars (non-proliferation, disarmament and peaceful uses of nuclear energy) for both nuclear weapon States and non nuclear weapons States. We will work closely with all States to translate these recommendations into balanced progress across all three pillars.

· On disarmament the Action Plan recognises the obligation for both nuclear weapon States and non nuclear weapon States to work to help create the conditions for a world without nuclear weapons. It also specifically notes the importance of developing efficient verification capabilities related to nuclear disarmament.

· The P5 agreed to work together on new confidence-building disarmament initiatives, including a working group to enhance understanding of P5 nuclear terminology, and a confidential UK-hosted expert-level meeting to discuss lessons learned from the UK and Norway's bilateral (the UK Norway Initiative - UKNI) work on the verification of nuclear warhead dismantlement.

· In December 2011 the UK hosted an expert-level meeting to discuss lessons learned from the (UKNI). This initiative is an example of the world-leading research the UK is undertaking in order to address some of the technical and procedural challenges posed by effective verification of nuclear warhead dismantlement.

· It is the first such undertaking by a nuclear weapon state, a non nuclear weapon state and the latest progress on this important work will be presented to the Preparatory Committee for the 2015 NPT Review Conference, in Vienna in April 2012. We held a briefing for the P5 on this work in London later in April.


· In September 2009, the UK held the a P5 Conference that brought together policy officials, military staff and nuclear scientists from all five Nuclear Weapons States recognised by the NPT to discuss disarmament obligations. It was the first conference of its type and it succeeded in further enhancing trust and confidence between the P5. At the May 2010 RevCon, the 189 parties to the NPT agreed Action Plans across the three pillars (nuclear disarmament, non-proliferation and peaceful uses of nuclear energy).

· In June-July 2011 the P5 met in Paris. The meeting successfully contributed to building mutual trust between the P5; reaching agreement on further work on new confidence-building disarmament initiatives, including the establishment of a working group to enhance understanding of P5 nuclear terminology. The next P5 meeting will take place in Washington later this year.


· The future of the deterrent was not included in the SDSR as the Government made it clear from the outset that it was committed to retaining a nuclear deterrent based on Trident. Instead we commissioned a separate value for money study. The VFM study has delivered £3.2 billion of savings and deferrals over the next 10 years.

· This has reduced the financial pressure in the early years, it has also removed all of the time contingency from the submarine programme and effective delivery of all stages of the programme are essential.

· The Vanguard class submarines will be around 37 years old when they leave service and the scope for further extension is limited.

· The outcomes most relevant to the replacement submarine were:

a. A delay to the In Service Date of the first replacement submarine until 2028 (and a life extension to the current Vanguard fleet to meet that date) and an extension of the production drumbeat from 30 to 36 months;

b. Agreement of a smoothed 7 boat Astute programme to ensure that industrial skills could be maintained through to the start of the production of the successor submarines;

c. A delay to the Main Gate approval point to 2016 and a deferral to that point of whether 3 or 4 boats will be required;

d. A reduction to 8 operational missiles, which in total will carry no more than 40 warheads;

e. A change in the assumption on missile tube diameter from 97» to 87» based on the emerging conclusions of the joint US/UK Common Missile Compartment team;

f. The commencement of the Submarine Enterprise Performance Programme, working with industrial partners to improve commercial arrangements and efficiency.


· The announcement of IG to Parliament was made by the Secretary of State on 18 May 2011.

· The completion of the SDSR allowed the IG Business Case for the successor submarine to be finalised. The Business Case recommended downselecting to a single submarine design powered by a new PWR3 nuclear propulsion system and entry into a £3bn assessment phase to finalise the detailed submarine design, the procurement and build strategies and to start work on some of the long lead items.


· The overall cost of the programme which includes submarine, warhead replacement and infrastructure is £15-20Bn at 2006/2007 prices, as stated in 2006 White Paper. The cost of the submarine programme are:


2006/07 prices

Cost at outturn (including inflation) noted in the 2011 Successor Parliamentary Report






Deferred, so no new estimate available



Deferred, so no new estimate available




· The cost of the submarine programme is within 2006 White Paper estimate of £11-14Bn at 2006 Prices. The Parliamentary Report highlights the cost of the Successor Submarine programme at Outturn, totalling £25Bn. This figure of £25Bn equates to the £11-14Bn estimate in the White Paper, but includes inflation.

· The cost of the Successor Assessment Phase is £3Bn at Outturn; this includes approximately £500M of long lead items. So far, the project has spent approximately £900M on Concept work. The total spend up to Main Gate is therefore expected to be £3.9Bn - in line with departmental guidance of spending up to approximately 15 % prior to Main Gate.

Long Lead items

· The programme expects to spend approximately £500M before Main Gate. This expenditure is for:

o The specialist high grade steel (Current plans are for it to be ordered by the shipbuilder in summer 2014 so it is ready for manufacture and cutting in 2016 if Main Gate approval is given. The quantity of steel has yet to be decided.)

o Some of the main boat systems (such as the computer systems, hydraulic systems, atmospheric systems, generators and communications systems)

o Some specialist components including steam generators and test rigs for the propulsion plants

· It will only be spent on the first three boats as it will not be decided until 2016 whether 3 or 4 boats are required.


· In the December 2006 White Paper, the previous Government explained that it had decided to participate in the US life extension programme for the Trident D5 missile, which will extend the life of the Trident D5 Missile systems out to around 2042.

· Decisions on whether we wish to acquire a successor to the life extended D5 missile, and what form any successor might take, are unlikely to be necessary until the 2020s.

· The exchange of letters between the then Prime Minister and the US President, (published on 17 December 2008), set out assurances from the US Government that, in the event they decide to develop a successor to the D5 missile, the UK will have the option, if it so wishes, of participating in such a programme and that any successor to the D5 should be compatible, or can be made compatible, with the launch system to be installed in our new SSBNs.

· This means we will be able to deploy an effective deterrent, should future Governments wish, throughout the life of the new submarines.


· Since 2006, work has been progressing in order to determine the optimum life of the existing warhead stockpile and the range of replacement options

· Under the 1958 UK-US Agreement for Cooperation on the Uses of Atomic Energy for Mutual Defence Purposes (the `Mutual Defence Agreement') we have agreed on the future of the Trident D5 delivery system and determined that a replacement warhead is not required until at least the late 2030s.

· Decisions on replacing the warhead will not therefore be required in this Parliament. This will defer £500 million of spending from the next 10 years.

· As part of the work to inform future decisions, we are now reviewing the optimum life of our existing warhead stockpile and identifying the range of replacement options that might be available.

· The existing nuclear warhead design is likely to last into the 2040s, although we do not yet have sufficient information to judge precisely how long we can retain it in service.


· Cruise missiles simply aren't as capable as ballistic missiles. They are slower, have a limited range, carry a smaller payload and are more vulnerable to missile defence systems.

· We are committed to maintaining the minimum deterrent necessary. If we used cruise missiles we would need many more missiles and submarines than the current ballistic-missile based system and there would be little, if any, cost savings and a risk that we would have a much lower and vulnerable capability.

· The 2006 White Paper ran through a number of options. No system was more cost effective than the submarine-borne Ballistic Missile system and none was as effective in producing a credible deterrent because of the advantages that a submarine-based deterrent has of invulnerability, range and its ability to operate without detection.


· We are investigating fully whether there is scope to maintain continuous deterrent patrols with a fleet of only three submarines but at present four submarines are needed to deliver CASD, so to move to three submarines would require radical improvements in submarine design, reliability, support arrangements and operation.

· This decision will be taken at the «Main Gate» in the purchase of the successor Submarine. The SDSR identified that this is expected to take place in 2016.


· The Government is clear that Scotland benefits from being part of the UK and that the UK benefits from having Scotland within it.

· The Government is not making plans for independence as we are confident that people in Scotland will continue to support the Union in any referendum.


· The Cabinet Office is leading the review, drawing inputs from different Government Departments. MIN(AF) is overseeing the work as it progresses. A full programme of work is in hand to address the questions set out in the Terms of Reference. It will consider possible systems and postures which could maintain the credibility of the UK's nuclear deterrent, including whether there are credible alternatives to a submarine-based system.