I was part of the team behind the UK Strategic Defence Review: Here is what shaped our thinking

The SDR’s vision calls for a revolution in how the UK finds, buys and uses technology to keep up with its adversaries.

Expert comment Published 2 June 2025 4 minute READ

Grace Cassy

Associate Fellow, UK in the World Programme

‘By 2035 the UK will be a leading tech-enabled defence power, with an Integrated Force that deters, fights and wins through constant innovation at wartime pace’ – this is the core vision of the UK’s Strategic Defence Review (SDR) 2025.

It was easy enough for us to write this single sentence, but it encapsulates a radical strategic shift in how the UK must organize to find, buy and use technology. It will be hard work to execute, but success is urgent – for the UK’s ability to deter adversaries, strengthen its industrial base, and to win if required to fight.

Why that vision? 

The SDR acknowledges that the international order is being reshaped. Russia’s war in Ukraine continues, but the US wants to focus on the Indo-Pacific region and at home. The UK and its European partners are rightly taking on more responsibility for their own defence as a result. Meanwhile China is vastly increasing production of advanced weapons systems, combining AI, drones, and maritime assets designed for saturation and surprise. Additionally, the UK is dealing with daily attacks against its infrastructure and economy in the grey zone of cyberspace. Taken together, it is clear that the threats faced by the UK are proximate, and in many respects already here.

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Grace Cassy speaks at the UK Ministry of Defence.

Ukraine has vividly demonstrated that the battlefield is no longer just kinetic – it’s cognitive, autonomous, and contested in milliseconds. The war has shifted the locus of defence innovation from well-established prime contractors to agile startups, who can rapidly respond to the pace of battlefield developments. This is happening at a time when advances in AI, quantum, and biotech are progressing at dizzying speed. 

UK defence is not currently set up to face the challenges of this new era. Procurement takes an average of 6.5 years for projects with a value of more than £20 million. 

The result is that the UK has a narrow base of large suppliers who have the balance sheet to survive the procurement cycle. Digital capabilities have been de-prioritized to fund other long-running equipment programmes. Put simply, the UK has raided the future to pay for the past. This cannot continue, as the Defence Secretary John Healey has made clear.

The Review therefore places innovation and pace at the heart of its vision. To deter, fight and win requires an ability to endure both above and below the threshold of war. As well as ships, tanks and planes, communications and digital networks must be able to survive and decide under fire. 

Threaded through all of this is the concept of tempo dominance – the simple maxim that the side that learns and adapts fastest, wins.

The creation of a Digital Targeting Web will enhance the UK armed forces’ ability to sense, operate and decide across domains – in the field as well as in headquarters. It will also force pace into the work to upgrade the UK’s digital foundations, from the Cloud to AI. The SDR calls for a significant upgrade to cyber capabilities and better protection for the UK’s Critical National Infrastructure (CNI). 

NATO Allies must also be able to fight together more easily. From software to supply chain, the Review argues for interoperability by default. This means open software standards, simple architectures, and an end to over-specification. Threaded through all of this is the concept of tempo dominance – the simple maxim that the side that learns and adapts fastest, wins.

Realizing the vision

Translating this into practice requires changing how the UK finds, buys and uses capability in a constant innovation cycle. The government’s commitments to increased defence spending are welcome, but as the defence secretary has acknowledged, how we spend the money is as important as the overall number. 

The UK must stimulate a deeper and broader pool of potential suppliers as part of a renewed partnership with the private sector.

The UK must stimulate a deeper and broader pool of potential suppliers as part of a renewed partnership with the private sector. Critical to that aim is the decision to ringfence 10 per cent of the equipment budget for novel technologies: for the first time, a defence review is providing formal protection for tomorrow’s needs. 

This money must flow via contracts as revenue to a wider pool of companies, complementing large manufacturers with the younger and more agile technology providers who have been critical to Ukraine’s war fighting. This should be the core function of the new UK Defence Innovation organization the Review proposes. 

The Review also has clear recommendations on how to inject pace into procurement through radical reform. It recognizes that systems created to procure aircraft carriers do not work for software or fast-evolving capabilities like drones. Such purchases should have a three-month timeline. This is a challenging target and will require different risk appetite. But it is an essential reform to stay in the race against adversaries who are deploying new kit in the time the UK currently takes to draft a requirement.

Once new capability is delivered, the armed forces must be able to use it. Trusted networks, an assured data fabric, and Secret-level Cloud are all vital parts of the 21st century armoury, making other weapons more lethal. Without them, talk of deploying AI and drones will remain just talk. Defence people too must be ready to work with this new tooling. The Review recommends the creation of a Digital Warfighters group as a frontline deployable capability, and digital upskilling across UK defence as a whole.

The ingredients are now in place for a flowering of technology companies that can serve defence and security and contribute to maintaining an edge against fast-moving adversaries. Ultimately, though, companies need to show revenue to keep attracting investment capital. 

The next two years will be critical to demonstrate to investors that there is a market in UK defence. 

Capital follows contracts: if government buys meaningfully from a wider range of suppliers, private capital will flow to them. For pure defence technology – as opposed to dual use technology, where there is also a commercial application – government is the only buyer. No-one else can make the equation work. With the ringfenced budget for novel technology the Review outlines, and the prospect of faster, more agile contracting, defence has the answer in its hands. 

The UK can become a beacon within NATO if it embraces its buying power: the next two years will be critical to demonstrate to investors that there is a market in UK defence. Technology companies will cluster where there is business to be won, creating high quality jobs and growth. If contracts don’t come, they will go elsewhere. 

The SDR has set some direction to the future. Its implementation will require changes to rules, processes and culture in UK defence. To some this may feel radical and uncomfortable. To others I spoke to during the Review process, it will feel liberating – and a necessary reform for our times.

Citizens, parliament and the media must also walk this path, accepting that the new world requires different ways of thinking about risk. If a new sensor or drone cannot deliver a ten-year value for money statement, or becomes obsolete in months, that is not a failure. It is the new reality given the pace of development in technology and especially AI.

As part of the Review team, I’ve seen the distance the UK has to travel. And I’ve also seen the brilliant people inside defence committed to delivering on the SDR’s vision. Now is the time to empower them.