Digital Economy Dispatch #292 -- The Defence Investment Plan's Sovereign Challenge

After a long wait, the Defence Investment Plan finally arrived this week. Was it worth the wait?

That question has two answers. The obvious one is a defence answer, and most of the coverage so far has focused there. The more interesting one, that I want to address, is what the DIP tells us about the state of AI development and adoption in the UK. Not the marketing version. The commitments-on-paper-with-money-behind-them version.

Read that way, the plan offers a mixed picture.

Most of the coverage is treating the DIP as a platforms story. Frigates. Jets. Nuclear powered submarines. Tanks. More than 80 pages of them. The International Institute for Strategic Studies (IISS), a major defence think tank, walks through the plan service by service, weighing which programmes have survived intact and which platforms have been sacrificed.

Yet, for me, the more important story is the digital layer underneath. And that layer is where the plan discusses how important it is that the UK has a "sovereign" approach, but never actually lets you know what it means. That should be a cause for concern.

First the Good News

The institutional design in this plan is comprehensive and clear.

The National Armaments Director Group has been led by Rupert Pearce since October 2025. It is the closest thing UK defence has produced to a GDS-like redesign of the defence operating model for the digital age. It merges seventeen organisations into four. It gives UK Defence Innovation a ring-fenced £400 million a year. It has six Commercial Pathways and a Segmented Acquisition Model. It claims it will generate £10 billion of savings over the decade, all to be reinvested into defence. It commits MOD to a first delivery report to Parliament by July 2027.

Seen from my “Making AI Work for Britain” viewpoint, this is a real attempt to move to a more agile delivery model underpinned by a “consolidate demand and diversify supply” philosophy. It has the shape of something that could work. The first real test is the major review in July 2027. I’ll certainly be watching that date.

But institutional design is only half the story. Underneath it sits an architecture question the plan must answer to deliver on the promises. It is focused on a “sovereign” approach for the UK. Yet, what that means is far from clear.

Three Ways the DIP Uses 'Sovereign'

So, what does the DIP mean when it talks about a sovereign approach to defence? At least three different things.

First, with respect to the nuclear enterprise, including warheads, submarines, reactor cores, fuels, and so on. The DIP identifies £63.6 billion in spending aimed at developing UK-based capabilities as required.

Second, in the industrial language with a mantra to "Buy British by default." It mentions a forthcoming definition of a British company and “Five Defence Growth Deals” across Plymouth, South Yorkshire, Scotland, Wales and Northern Ireland. These are real intentions with important outcomes for the UK, especially regarding jobs, skills, and the defence industry’s role in the broader UK economy.

Third, in the digital and AI layer. This is where things become much more hazy. It looks as if "sovereign" is being used as a slogan draped over decisions that have not been made.

The Decisions No One is Naming

Three components sit at the centre of the UK's future defence infrastructure. The Digital Backbone is the connectivity and data infrastructure that everything else runs on. The Digital Targeting Web is the kill chain: the system that links sensors, decision-makers and weapons so a target can be identified and struck faster than the adversary can respond. Underneath both sits a Defence-wide Secret Cloud, promised as a minimum viable product “later in 2026”.

Together these deliver the essential plumbing that turns individual platforms into a networked fighting force. The DIP announces that the Digital Backbone gets £5.5 billion over four years. The Digital Targeting Web gets £1.8 billion. Both are described in the DIP as underpinned by "world leading AI and software".

However, the DIP does not name the provider. It does not set the architecture principles. It does not describe the exit terms. It does not commit to sovereign compute floors. It defers the Defence Strategic Approach to AI, and the frameworks for Dependable AI and Responsible Use of AI, to future publication.

That's a critical £7.3 billion decision. It underpins almost every AI-branded programme in the plan. It will be finalised later this year. The terms are undefined at publication.

Now compare the AI-branded programmes. Taskforce RAID: £100 million over four years. Project FRONTIER: £100 million. Land AI C2: £80 million. AI for underwater dominance: £20 million. Total named AI investment: about £300 million.

The architecture layer is more than twenty times the size of the AI-branded layer. And it is where every meaningful sovereignty question lives.

 Why This Matters

Understanding the details of these decisions will determine the sovereign nature of the UK’s defence infrastructure. If the Secret Cloud is a hyperscaler tenancy, that may be defensible on grounds of speed. But it is not sovereign. And it needs an exit strategy from day one.

If Project FRONTIER's compute sits in commercial data centres on someone else's chips, that may be defensible on grounds of capability. But the £400 million sovereign chip procurement announced in June needs to connect to it explicitly.

If the model layer for the Digital Targeting Web is a fine-tuned foundation model from a US provider, that may be defensible on grounds of performance. But the evaluation, red-teaming, dependency mapping and switching costs need to be visible to Parliament before the contract. Not after.

None of these choices is wrong. All of them can deliver capability faster than building sovereign alternatives. The point is not that MOD should build everything itself.

The point is that "sovereign" in the DIP's digital chapters is doing work that "smart-buyer" ought to be doing. The two are not the same. Consolidating demand, diversifying supply, and buying with exit-by-design terms. That is what makes a customer sovereign in a market it does not own. It should be explicit and clear in the DIP. It is not.

Key Questions to Address

Seen through this lens, five important questions must be answered in the spirit of the smart-buyer model.

1. Who provides the Defence-wide Secret Cloud? Under what terms? What are the exit conditions?

2. What is Project FRONTIER's compute strategy? How does it connect to the £400 million sovereign chip procurement announced in June?

3. Where does the model layer for the Digital Targeting Web come from? How is it evaluated? What happens when the supplier changes its pricing, its terms or its model?

4. What are the acquisition standards for Dependable AI and Responsible Use of AI? When are the frameworks published?

5. How do the Defence Growth Deals connect to the compute geography, so that "Place" as a growth-lens criterion is more than a paragraph?

These are answerable questions. They are also the ones most likely to go unasked. Political attention will go to platforms. Technical attention will go to programmes. The architecture layer sits between the two. And it is where the sovereignty of the whole plan is either quietly established or quietly given away.