UK lost year of mobilising for potential Russian attack due to DIP delays, MPS told

Key figures behind the UK's Strategic Defence Review, a guidebook for British security over the next decade, have criticised "dangerous" delays to the investment plan supporting it.

Lord Robertson of Port Ellen, a former UK defence secretary and Nato chief, and retired General Sir Richard Barrons are two of the three external reviewers who helped shape the SDR, which was published in early 2025.

Alongside Dr Fiona Hill, they outlined the focus areas for transformation over the following 10 years – a blueprint for the UK in remaining credible as a global player in defence, pre-dating the detail of the Defence Investment Plan (DIP) by more than a year.

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Sending someone's children into the field underprepared 

Giving evidence to the Defence Select Committee in Parliament, Gen Sir Richard said: "For me, by far the most dangerous consequence of the year's delay is that the Prime Minister says Russia could attack the UK by 2030 and we essentially lost a year of mobilising for that. 

"That is profoundly dangerous."

The external reviewers described having little to no involvement in the DIP itself.

"You're going to be confronting a moral failure because you'll be sending today's Armed Forces, who are all somebody's children, into the field in three years' time knowing that you decided not to prepare them properly and, as a result of that, more get killed and wounded than was necessary," Gen Sir Richard said. 

National resilience and preparedness for war have been widely discussed as areas for improvement in the UK, particularly in light of the threat posed by Russia.

In April, months before the long-awaited DIP publication, a study from think tank Rusi suggested a large-scale mobilisation event could see e-learning rolled out, to cover military basics for the UK population.

The gap between the SDR and the DIP explaining how the UK may be able to pay for the SDR has seen seismic shifts in the security landscape.

Lord Robertson said: "Since we wrote the report, while they were debating the Defence Investment Plan, we had the conflict in the Gulf in which the United Kingdom is playing a serious part, we had the Coalition of the Willing being invented, led by Britain and other European countries, following any ceasefire in Ukraine."

The High North and the SDR's suitability 

The High North has also pulsed brightly on Nato's radar in the time that has elapsed since the experts sat down to help write the SDR.

"We built this Strategic Defence Review based on an assessment of 10 years," Lord Robertson said. 

"That was our assessment at the time for when a peer opponent might challenge the United Kingdom. That clearly has now been accelerated, and quite simply we're running out of years, and the reality is that the challenge is now bigger, more serious, and earlier than we had anticipated, and yet the Defence Investment Plan itself doesn't come up to it."

While the security picture may have changed and criticism of the defence budget continues, both insisted the review is still suitable to guide the UK into the next decade.

"What is encouraging is that our Strategic Defence Review remains the model," Lord Robertson added.

"It remains the outlined plan for the future, and therefore doesn't need to be revised or redone, it’s still there, and it's still serious, and it is transformational, and if it's carried out properly then both industry and people in the ministry itself will be given heart," Gen Sir Richard said.