UK Defence in 2025 - ambition is the variable

Summer 2025 will see the publication of the UK's latest Strategic Defence Review (SDR). The SDR Terms of Reference are explicit that the review is tightly bounded by budgetary constraints specified by the new Labour Government:
Purpose
The SDR will determine the roles, capabilities and reforms required by UK Defence to meet the challenges, threats and opportunities of the twenty-first century, deliverable and affordable within the resources available to Defence within the trajectory to 2.5%. The Review will ensure that Defence is central both to the security, and to the economic growth and prosperity, of the United Kingdom.
Although the 'trajectory' to 2.5% of GDP has not yet been specified and is not expected until the Spring 2025 Budget, this represents a significant constraint on the work of the review team.
In December, the Commons Defence Committee held an inquiry session with two of the SDR's lead reviewers, providing an opportunity for the committee to grill witnesses Lord Robertson and General Sir Richard Barrons on their approach.
One of the first questions was on the subject of this budgetary constraint and what would happen if the review team identified a task or capability that would require greater spending than 2.5% GDP. The response by Lord Robertson was was very explicit - "we are living within the envelope that has been laid down for the terms of reference".
The witnesses were challenged on past failures and what they had learned from previous reviews. General Barron gave a refreshingly candid response -
"We remind ourselves every morning that every review in my working life has failed, generally within two years, for a combination of two reasons. The first is that they have not predicted what has actually happened in the world. The 1997 review obviously did not predict 9/11 and there are many other examples. Our objective has to be as least wrong as possible in terms of how we design a formula for the future.
The second reason why they have failed—and the 2010 review is the most powerful example—is because they have left an enormous gap between ambition and resourcing. They had a presumption that massive efficiencies would close that gap and other things that would make the programme more difficult would not happen, but they did happen and efficiencies did not appear".
While there is little the SDR can do to polish the MOD's crystal ball for predicting the future, it can certainly address the omnipresent gap between the UK's defence ambitions and resources. With the SDR accepting that financial resources are fixed by the 2.5% GDP budget remit, the conclusions of the review can only be reached by adjusting the dial marked "ambition".
This of course is not as simple as it sounds. As pointed out by committee member Mike Martin MP, accepting the 2.5% GDP limit guarantees that ambitions must be reduced, for the simple reason that the under-funding of the current Equipment Programme was last assessed as £17bn - a sum larger than the funding increase that will result from 2.5% GDP -
Mike Martin: If I may push you gently on this, if we are setting it to a 2.5% envelope, that implies that you are going to be arguing in the report for a reduction of our ambitions.
Lord Robertson of Port Ellen: Why would we be reducing our ambitions?
Mike Martin: Defence is not currently fully funded. There is a £17 billion hole in the equipment programme, for instance.
Lord Robertson of Port Ellen: We are operating on the basis of the terms of reference that we were given and we will make our recommendations based on that.
We should be able to assume that certain defence outputs are non-negotiable - defence of the UK homeland and overseas territories, and meeting our obligations the the NATO alliance. These are the baseline and should not be considered 'ambitions'. The use of the word 'ambition' implies recognition that there are certain current defence tasks or capabilities that are discretionary or "nice to have", and that these are the ones that will come under scrutiny by the SDR.
After decades where the political imperative to be seen as 'Global Britain' has not been matched by a willingness to fund those ambitions, and where the dedication and professionalism of UK Armed Forces personnel has been exploited on deployments that were under-resourced and burdened with obsolete equipment, it will be a refreshing change if this review is the one that finally ends the cycle of asking for too much with too little. Time will tell...