Former Nato chief warns UK security 'in peril' as he accuses Starmer of 'corrosive complacency'

The UK's security is "in peril" and Sir Keir Starmer's government has shown "corrosive complacency" towards defence, a former Nato secretary general has said.

Lord George Robertson, the former Labour defence secretary who wrote the government's Strategic Defence Review (SDR), will accuse "non-military experts in the Treasury" of "vandalism", in a speech to be delivered later on Tuesday.

While the SDR was delivered in June last year, the 10-year defence investment plan to fund it has been repeatedly delayed and Lord Robertson told the Financial Times Sir Keir was "not willing to make the necessary investment".

A government spokesperson said the SDR was "backed by the largest sustained increase in defence spending since the Cold War, with a total of over £270 billion being invested across this Parliament".

In a directly political intervention, Lord Robertson - who is now a key government adviser - will warn in his speech: "We cannot defend Britain with an ever-expanding welfare budget."

Speaking in Salisbury, he will say: "We are underprepared. We are underinsured. We are under attack. We are not safe... Britain's national security and safety is in peril."

He will add: "There is a corrosive complacency today in Britain's political leadership. Lip service is paid to the risks, the threats, the bright red signals of danger - but even a promised national conversation about defence can't be started."

Defence spending last year was 2.3% of GDP (around £66bn). A defence official highlighted the government's target to spend 3% of GDP on defence by the end of the next Parliament and 3.5% of GDP on core defence by 2035.

Welfare spending is forecast to be 10.6% of GDP, or £322.6bn, in 2025 to 2026.

The strategic defence strategy review was published in June 2025 and the government accepted it would implement all 62 of the review's recommendations, but is yet to share how it will fund these plans.

There have been reports that the plan has been held up over disagreements within government about funding the SDR, as well as how to fund existing defence plans.

The prime minister previously said the investment plan was on his desk and was being "finalised".

Strategic goals listed in the SDR included a Nato-first defence policy and a move to "war-fighting readiness" to establish a more lethal "integrated force" equipped for the future.

Some of the details also included a £11bn annual budget for front-line kit and the creation of a "new hybrid Royal Navy" that uses aircraft, drones, warships, submarines to patrol the north Atlantic "and beyond".

Lord Robertson's apparent suggestion that the government could find money by reducing the welfare bill may be one that is shared by the Chancellor Rachel Reeves.

However, the government's efforts to make savings in that area had to be abandoned last year, following fierce opposition from backbench Labour MPs.

A government spokesperson said: "We are delivering on the Strategic Defence Review to meet the threats we face."

Conservative leader Kemi Badenoch said she agreed with Lord Robertson, stressing "we need to get serious" on defence. Speaking to BBC Radio 5 Live, she suggested the Tories would "repurpose funds from net zero projects to invest in our military".

Speaking to the BBC's Today programme, General Sir Richard Barrons - another of the SDR report's authors - agreed with Lord Robertson that "there's an enormous gap between where we have to be to keep the country safe in the world we now live in and where we actually are".

Sir Richard said in future the organisation will see "a European Nato doing much more and the US doing much less".

"The US cavalry is not coming to bail us out now," he added, as he warned that the Royal Navy and Royal Air Force were "too small and too undernourished".

Following Russia's invasion of Ukraine and the re-election of US President Donald Trump, the UK, along with other Nato countries, has come under pressure to boost its defence spending.

Trump's campaigning resulted in an agreement by Nato leaders to ramp up defence spending to 5% of their countries' economic output by 2035, which the US president called a "big win for Europe and... Western civilisation".

The commitment to raise defence spending over 10 years involves at least 3.5% of each member state's GDP on core defence expenditure by 2035, plus up to 1.5% on a broadly defined series of investments loosely connected to security infrastructure.

Despite this agreement, the US president has threatened to withdraw US support for Nato after he wrote the organisation "WASN'T THERE WHEN WE NEEDED THEM".

The head of the British military, Chief of the Defence Staff Sir Richard Knighton, told the BBC last month that he rejected accusations that the UK had been ill-prepared for the current conflict in the Middle East, which began on 28 February with a joint US-Israeli attack on Iran.

But he said it was "probably the most dangerous time of the last 30 years".

There were questions as to why a Royal Navy destroyer was not deployed to the region sooner since the US military build-up in the region had been going on for months.

Sir Keir has repeatedly ruled out direct UK military involvement in the conflict.

Refusing to join Trump's military blockade of the Strait of Hormuz, the prime minister told the BBC: "My decision has been very clearly that whatever the pressure - and there's been some considerable pressure - we're not getting dragged into the war".

"That's not in our national interest, because I'm not going to act unless there's a clear, lawful basis and a clear thought-through plan."

On Tuesday, Sir Keir will chair the first meeting of the Middle East Response Committee - a group set up to replace the ad-hoc emergency Cobra meetings that had been held to discuss the war in Iran.

The committee will look at the diplomatic side as well as the economic fallout from the conflict.