What’s next for the UK's armed forces? Some key takeaways from the Strategic Defence Review
The UK’s Strategic Defence Review (SDR) 2025, Making Britain Safer: Secure at Home, Strong Abroad, was finally released on June 2. The document which promises a ‘root and branch’ review of the UK’s defence strategy looks to revitalise British defence policy with the largest spending increase since the Cold War - from 2.5% of GDP by 2027 and 3% in the next Parliament. Against a backdrop of the ongoing war in Ukraine, increased Russian aggression, and increased global instability, the review states that it will move Britain onto a "warfighting footing" committing to rearming, reindustrialising and preparing for a major global conflict.
It was initially announced on July 16, 2024, with an expected publication in the first half of 2025. The review was released around two weeks later than originally planned.
This slight delay could be attributed to the complexity of the review process and the need for thorough consultation. However, one wonders if the rapidly changing geopolitical landscape of the past year will have led to several rethinks in strategy.
A centrepiece of the review is a reaffirmation of the continuous at-sea nuclear deterrent, and a £15 billion investment in the Astraea nuclear warhead programme. This is backed by a new submarine production line, including up to 12 SSN-AUKUS submarines jointly developed with the United States and Australia.
The review is equally focused on new threats in the digital space and air defence. The SDR has announced creation of a Cyber and Electromagnetic Command and plans to invest over £1 billion in a “Digital Targeting Web”, as well as new funding for Integrated Air and Missile Defence (IAMD) signal that future threats.
Importantly, unlike previous reviews which have consistently cut or amalgamated sections of the military, this one is defined more by what it promises to build than what it cuts. The document confirms that ageing ships will be retired and replaced under the UK’s existing shipbuilding strategy. Similarly, no Army regiments will be disbanded, and the overall trend is towards growing the size of the military.
Here is my own summary of what the review means for each service branch. No doubt if you have been following the various leaks leading up the full release much of this will not be a surprise.
The British Army:
The Army is being restructured for a conflict in Europe, under NATO’s command. The aim is for it to be capable of fielding two full divisions—including a newly developed “Recce-Strike”model built around long-range precision artillery, drones, and air defence. This responds directly to lessons from Ukraine, where this new form of warfare has become the norm.
The review sets an ambitious target to grow the Army to 100,000 soldiers, including a 20% boost to the Reserves. It states the Army will shift toward a “20-40-40” platform mix (only 20% crewed vehicles), with uncrewed and expendable drones making up the bulk of new combat systems. The new Ranger Regiment and Special Operations Brigade will also be scaled up to contribute to NATO’s forward defence in Europe and the Middle East, to respond to new “hybrid warfare” threats.
The plan to increase the size of the Army will be welcomed by higher-ups but they commitment to doing so won’t solve the problem of bringing onboard new personnel (this is true of the other services as well). Poor pay and living conditions and lengthy outsourced recruitment processes, as well as a younger population generally apathetic to military service will still be a problem in years to come.
The Royal Navy:
The Navy’s submarine capability is at the core of the service’s future. The UK will continue construction of the Dreadnought-class SSBNs, maintain its ‘continuous at-sea deterrent’, and build up to 12 SSN-AUKUS class submarines in partnership with the US and Australia. These platforms will extend Britain’s nuclear strike capability through to mid-century.
The surface fleet will become evolve a “hybrid navy”, pairing new Type 26 and Type 31 frigates with autonomous platforms for mine hunting and anti-submarine warfare. The review older platforms such as the remaining Type 23 frigates will be replaced on a rolling basis. Likewise, HMS Albion and HMS Bulwark—the Navy’s two amphibious assault ships—are not granted reprieve indefinitely; their future is left open.
A new mission to protect undersea infrastructure—such as fibreoptic cables and energy pipelines—places the Navy’s in a new strategic role in wider European defence.
The Navy seems to have come out of the review quite well, especially regarding modernising its equipment. However, commentators have pointed out that the replacement of older equipment is taking too long and will leave the Navy on the back foot if they are scrapped before new vessels are launched.
The Royal Air Force:
The air force will be restructured around the demands a major conflict. The RAF will invest in the Global Combat Air Programme (GCAP)—its sixth-generation fighter platform—alongside further purchases of the F-35 fighter. The emphasis is on contested air dominance in coalition operations, especially across Europe.
Homeland defence also gets renewed attention: the review commits over £1 billion for an IAMD, strengthening the UK’s radar, missile shield and ground infrastructure. Referred to in some corners as a UK “Iron Dome’’(in reference to the Israeli defence system), this is intended to respond to new threats like Russia’s rumoured hypersonic missile program.
The Hawk T1/T2 trainer fleet will also be retired, and a new fast-jet training system introduced. Meanwhile, strategic bases, such as RAF Brize Norton, will be upgraded to support deployments and airlift capacity for different theatres.
The SDR has garnered mixed reactions. Many online critics have argued that the ambitious plans lack clear funding commitments and may be overly optimistic. I am inclined to agree. Other concerns include the feasibility of meeting the proposed spending targets and the potential impact on other public services. I can imagine this will prove to be a point of contention for many people whose political fall more to the left of centre, as further cuts squeeze British society even further - a post I saw in the process of writing this was headlined “Starmer Bangs War Drums at Arms Factory.”
There has also been a call for greater public involvement in defense, drawing parallels to the Scandinavian "total defence" approach, where civilians play an active role in national security.
Something akin to this was rumoured to be included in the review in the form of a “Home Guard,” similar to that which exists in Scandinavia, in order to guard key infrastructure. This concept naturally has a historical precedent in the UK, both in the form of the WW2 equivalent and the Home Service force of the Cold War, but it doesn’t seem to have made an appearance. I do have some thoughts on this concept and will likely write something about it later.
Ultimately, the new lengthy, jargon heavy document which may prove to be something and nothing. But, given the stagnant state of the armed forces it was long overdue and will hopefully prove to be a step in the right direction.
You can find the full document of the SDR here.