The forthcoming Strategic Defence Review (SDR) is expected to be a defining document for the Government. At a time of profound geopolitical disruption, the SDR will give the clearest signal yet of how the UK intends to confront a new era for defence and security.
Here are six things to look out for:
1. What does a NATO-first defence posture mean in practice?
The world feels very different today compared to July 2024, when the newly elected Labour Government launched the SDR on an explicitly NATO-first principle, with the alliance as the cornerstone of UK security. Donald Trump’s administration has challenged many basic assumptions and called into question US commitment to NATO. With the US apparently wanting to focus primarily on the threat posed by China, the UK needs to take a more prominent role in defence of the continent. If, as is speculated, the US is prepared to hand over the role of Supreme Allied Commander Europe (SACEUR) to a non-American for the first time in NATO’s history, the shifting balance of power and responsibility within the alliance would be cemented.
How the UK can take on a more leading role within NATO will be a key question for the SDR to answer.
Some are calling for a reversal of the Indo-Pacific tilt proposed by the 2021 Integrated Review to refocus limited resources on the European arena. However, an explicit reversal of the tilt seems unlikely, given the Government’s enthusiastic support of the AUKUS security partnership and the Carrier Strike Group deployment to the Indo-Pacific. Today’s threats cross geographical regions, as shown by the presence of North Korean troops fighting with Russia against Ukraine.
China is also heavily invested in Europe in numerous ways, and its focus on advanced disruptive technology will not be geographically constrained. Nevertheless, the balance of resources between the Euro-Atlantic and Indo-Pacific regions is a fundamental question for the SDR to grapple with.
2. US vs EU Collaboration
A further balancing act for the SDR to consider is between collaboration with the EU and the US. The Government has been clear in recent months that the US is the UK’s most important and closest ally on defence and security and will remain so. The Five Eyes intelligence partnership is fundamental to UK security and US-UK defence and intelligence arrangements are as closely integrated as possibly any two nations on earth.
However, with talks ongoing for a UK-EU defence and security pact, we can expect to see increased UK-EU collaboration. Discussions about European collaboration within NATO are intensifying, for example on role specialisation and what capabilities each country can contribute. Amid increasing defence budgets, these talks may be a factor in shaping future procurement priorities across the continent and in the UK.
The Government will be mindful that for all the recent talk of the US being a transactional and unreliable ally, Brussels’s linking of fishing rights to access to an EU-wide procurement fund and German wrangling over Typhoon exports shows that dealing with our European allies also brings challenges.
How the SDR foresees the UK balancing future collaboration with our American and European allies may be one of its most consequential conclusions, and a more detailed approach will need to be formulated if, as the Prime Minister claims, the UK can and will have to partner with both rather than make a binary choice. What these partnerships will look like in practice is still to be determined.
3. Personnel vs Equipment and Industry
In opposition, Labour opposed Government cuts to troop numbers, frequently citing that the Conservatives had reduced the Army to its smallest size since the Napoleonic Era. Now in Government, Labour ministers face the same trade-offs as their predecessors.
An increase in the size of the Army from its current level of 70,000 back to its 2010 level of 100,000 would wipe out a significant amount of the additional funding allocated to reach 2.5% of GDP, with little left to invest in the industrial base or the new technologies and capabilities the Government has committed to.
Previous cuts have been justified by governments and service chiefs on the basis that the strength of the Armed Forces should be measured by lethality rather than raw numbers. But one lesson from the Ukraine War is that mass still matters. Where the SDR falls on the size of the Armed Forces will be an important measure of future priorities.
4. Future Combat Air Mix – Tempest plus what?
Despite initial uncertainty following the launch of the SDR process the Government has enthusiastically endorsed the Global Combat Air Programme (GCAP), the project to build the Tempest sixth-generation jet with Japan and Italy. That was before recent geopolitical events further increased Tempest’s export potential and the importance of retaining a sovereign combat air industrial base.
With Tempest apparently safe, the SDR will look to answer the unresolved questions over the RAF’s future combat air fleet.
Thirty-two Tranche-1 Typhoons, almost a quarter of the RAF’s combat fleet, will retire this year. The question of how to fill that capability gap has become more than a merely operational one. It now has a symbolic element which some will use as a test of the UK’s balance between Europe and the US.
Unite and other unions have been lobbying hard for the Government to buy replacement Typhoons rather than more F-35s. They claim this would help sustain UK industry in advance of Tempest production. However, funding has already been allocated to increase the F-35B fleet to 74 aircraft, enabling three carrier-capable squadrons to be operational by 2033. There has even been recent speculation that the Government is considering ordering non-carrier capable F-35As. With limited resources forcing a need for compromise, where the Government opts to make a difficult decision on the combat air fleet is shaping up to be one of the most symbolic and significant of the SDR.
5. Procurement Reform and New Tech
One of the most eyebrow-raising announcements at the Chancellor’s Spring Statement was a new target of spending 10% of the MOD’s equipment budget on novel technologies such as drones and AI from next year. This is the clearest signal yet that the Government recognises the need to embrace automation and the new technologies which are reshaping and often disrupting the nature of modern warfare. Given the pace of development of these technologies, especially in the war-fighting theatres such as Ukraine and the Middle East, it is essential that the procurement process is streamlined and has a greater focus on spiral development.
How the Government envisages procurement reform to ensure novel equipment and technology is delivered more rapidly will be an important question to be answered by the SDR and, in more detail, the Defence Industrial Strategy.
6. Future Defence Spending
Despite a widespread welcome from Parliament and industry for the Government’s commitment to spending 2.5% of GDP on defence by 2027, questions remain over whether that will be sufficient for a new era of European security. Many NATO allies, including the alliance’s newest members Finland and Sweden, have recently announced plans to go further and faster on defence spending than the UK. The baseline among the nations of the UK-led Joint Expeditionary Force (JEF) appears to be moving to over 3.5% of GDP.
Decisions taken in Washington, as well as the need to send a force to Ukraine as part of a peace deal or even the upcoming NATO summit in June, may force the Government to urgently reassess its spending plans.
It will be interesting to see if the SDR makes an explicit provision for a future defence spending increase and, if future funds above 2.5% of GDP were to be made available soon, where they should be prioritised.
