UK defence spending faces call for domestic focus after thinktank’s overseas commitments estimate

A Transition Security Project report described by the Guardian on 8 October 2026 estimates that overseas commitments accounted for about 23% of the UK’s 2024/25 military budget. The thinktank wants more of a planned rise in defence spending directed towards domestic defence, arguing that the current balance risks wasting public money. The estimate and that judgment are the researchers’ conclusions; the government’s published investment plan confirms the spending increase but does not assess the thinktank’s figures.

How much does the report say overseas commitments cost?

The researchers estimate that overseas commitments cost just over £14bn in 2024/25 and say the true figure could be higher. According to the Guardian’s account, roughly £2.8bn of the estimated spending was outside Europe, including commitments involving bases in Cyprus, Kenya and Oman and other sites used as strategic hubs. These are estimates attributed to the Transition Security Project, rather than audited totals established by the government’s funding explainer.

The report describes Britain as the most overseas-committed military among European NATO members under its measure. The Guardian notes an important distinction: France has more personnel posted abroad. The comparison therefore concerns the measure used by the researchers, rather than a claim that Britain has the largest number of service personnel stationed overseas.

The thinktank also estimates that the UK has spent more than £51bn in modern terms on military interventions in Iraq, Afghanistan, Libya and elsewhere since 2001. It uses that history to question whether a continued emphasis on projecting military power abroad makes the UK safer. Its proposal is to review the military’s posture and give domestic defence a larger place in spending decisions. Whether that change would reduce waste or improve security has not been demonstrated by the spending figures alone.

What the UK defence investment plan commits to

The explainer projects core NATO defence spending at 2.7% of gross domestic product from 2027/28 and confirms a commitment, alongside NATO allies, to reach 3.5% of GDP by 2035. It says funding and plans for reaching 3% in the next Parliament will be set out at the next spending review. The timetable matters because the thinktank is asking ministers to reconsider priorities while larger budgets are being planned, before all of the future spending decisions have been detailed.

The government’s funding table identifies £4.7bn of the £15bn package as still to be funded at Budget 2026. That leaves a material question about how part of the four-year increase will be financed. It does not, by itself, answer the separate question raised by the thinktank about the balance between overseas commitments and defence closer to home.

Why the thinktank wants a change in priorities

Kevin Cashman, a co-author of the report, argued against putting more money into what he described as a bloated military sector aligned with the United States. Fellow co-author Khem Rogaly called overseas deployments wasteful and urged the government to focus military resources on defence while directing public investment towards health, housing and the climate emergency. Those comments state the authors’ policy position; they are not findings in the government’s plan.

The Guardian reports that the Defence Investment Plan refers to continuing commitments across several continents. It also reports awareness among defence officials that spending targets can increase the risk of waste, and describes preparation for a possible war in Europe as a priority. The government’s funding explainer, meanwhile, says the new money is intended to provide capabilities for service personnel and improve efficiency. It contains no direct response to the Transition Security Project’s estimate of the share spent on overseas commitments.

The dispute is therefore about what the planned increase should fund, as well as its size. The thinktank’s budget share, cost estimates and comparison with other European forces remain attributed findings: its full report and methodology were not independently inspected for this article. The published government figures establish the scale and stated purposes of the investment plan, but do not settle whether shifting resources away from overseas missions would deliver the savings or security benefits the researchers seek.