The Main Gate decision on the construction of a new fleet of nuclear ballistic missile submarines at a capital cost of £20-25bn is expected early 2016. This Memo to the Prime Minster clarifies that there will in fact be a range of options available when a decision is to be made including the commissioning of four, three or two Successor submarines, further delay in the programme or a decision to begin the process of divesting the UK of its nuclear arsenal.
These choices are all dependent on the forthcoming Defence and Security Review, which should include an assessment of the role of Trident in meeting current and future threats, consideration of changes to defence posture and/or alternative delivery systems and the industrial practicalities of further delay as well as the opportunity cost for wider defence spending of going ahead.
A summary of the four options that the next Government will need to choose from prior to Main Gate, and then put forward to MPs to vote on include:
1. Like for like replacement and retaining continuous patrolling: commissioning four submarines at an estimated capital cost of £20 to £25 billion in the period 2016 to 2033, and annual running costs of some £1.5bn in today’s prices. The Successor submarines will not require mid-life refuelling, so three submarines may be sufficient to ensure continuous patrolling – a final decision on this may not be required until 2022.
2. Changing to irregular undisclosed patrolling patterns, retaining a capability to reinstate continuous patrolling for an extended period during crises: reducing a requirement to a two submarine fleet, with potential average savings of up to £1bn a year.
3. Delay: it may be feasible to delay the Main Gate decision up to 2021 (especially with option 2 above) - see recommendation three below. This could defer much of the capital expenditure from the current five year Parliamentary period, achieving annual savings of up to £1.5bn. It would also open the possibility of further savings by allowing proper consideration of dual-role alternatives able to deliver a genuinely minimum nuclear deterrent
4. Decide not to renew the current Trident fleet for a range of defence, deterrence, moral, legal, foreign policy, political and humanitarian reasons: this would save up to £80 billion over the expected lifetime of the programme.
This memo makes four immediate recommendations to the incoming Prime Minster:
1. Include Trident replacement fully in the forthcoming Defence and Security Review (DSR) so that it can be considered alongside other capabilities, nuclear and non-nuclear, and announce that final preparations for the Main Gate decision will only start after the DSR has been completed.
2. Commission an analysis of the practicalities and implications of a further delay in the Main Gate decision with or without a change in operational posture.
3. Request an update to the Trident Alternatives Review immediately so that it can inform the forthcoming Defence and Security Review (DSR), with a view to reporting in public and classified form by September
4. Consider a positive diplomatic announcement before the NPT Review Conference closes on 22 May demonstrating commitment to treaty disarmament obligations.
BASIC is committed to continuing dialogue about how the UK meets its defence needs and contributes most effectively to an improving global security environment. This memo represents the views of BASIC, but was informed by views of others and discussions at our event on Trident Options that we hosted on March 4th.
The MoD wrote a response to BASIC's Memo to the Prime Minister on 10 June, and in summary stated:
- The government will renew all four boats which will serve until at least 2060
- Trident will not be considered as part of the SDSR
- CASD will be maintained
- Main Gate decision will be made in 2016 to allow for an in-service date for the first Successor submarine in 2028.
- The 2013 TAR will not be updated.
- The government remains committed to the NPT process.