The world breathed a sigh of relief as the US and Iran agreed at the 11th hour to a two-week ceasefire after a diplomatic intervention from Iran. Hours after Donald Trump had threatened widespread bombing of Iran’s power plants and bridges, warning that “a whole civilisation will die tonight”, both countries agreed to a temporary ceasefire and Iran agreed to a temporary reopening of the strait of Hormuz.

For the British government, whatever happens next, the conflict has revealed some important – and sometimes painful – lessons about the UK’s geopolitical standing and military readiness.

The special relationship

In his first year as UK prime minister, Keir Starmer worked hard to cultivate a positive relationship with the US president, gaining a reputation as a supposed Trump whisperer. Just over a year ago, Starmer sat side by side with Trump in the Oval Office, gushingly handing over an “unprecedented” second state visit invitation from the king. Trump said the pair got along “famously”.

That warmth, confected or otherwise, is long in the rear-view mirror. Almost a month and a half since the start of the conflict in Iran, the special relationship is in tatters. Trump has reacted furiously to Starmer’s decision not to support the initial strikes in the Middle East, dismissing him, on several occasions, as “no Winston Churchill”, repeatedly mocking the UK’s military capability and accusing Starmer of seeking to “join wars after we’ve already won”.

Starmer has quietly but pointedly distanced himself from the US president while insisting the relationship between their nations remains strong, stating: “Sharing intelligence every day to keep our people safe – that is the special relationship in action. Hanging on to President Trump’s latest words is not the special relationship in action.”

British military readiness

Experts have said the war in Iran has exposed the UK’s lack of military capacity and a relative defensive weakness. HMS Dragon only arrived in the eastern Mediterranean three weeks after an Iranian-made drone hit the British base of RAF Akrotiri – and the destroyer has now docked in the eastern Mediterranean after problems with its onboard water systems.

Matthew Savill, the director of military sciences at the Royal United Services Institute thinktank, said the delayed arrival revealed that “one of the military’s big problems is giving the government contingency options”. The former first sea lord Adm Lord West of Spithead has argued that the navy is in its most “parlous state” for 60 years, saying it is too small, underfunded, and unable to protect the nation.

At the end of the cold war, a period during which Britain spent 3.2% of its GDP on defence, the UK had 51 destroyers and frigates. By 2007 the number had halved to 25, and it now stands, according to analysts, at a small ageing fleet of 13. The UK spends 2.4% of GDP on defence, a figure that Labour has promised to lift modestly to 2.5% by April 2027.

At last summer’s Nato summit, Starmer agreed to lift defence budgets by about £30bn, to 3.5% of GDP by 2035. In the spring budget, the chancellor, Rachel Reeves, referred to reaching 3% “for the next parliament”. A 10-year defence investment plan setting out spending on a line-by-line basis has been delayed since last autumn with no date for publication.

Military figures have long argued that successive governments have been reluctant to acknowledge what one former senior figure describes as the “rhetoric to reality gap” – where the UK presents itself as a global military power but lacks the resources to actually be one.

Britain’s exposure to oil shocks

Even if the strait of Hormuz opens immediately, energy analysts are clear that the conflict in the Middle East is likely to mean further cost of living woes for the British public, with higher costs at the petrol pumps already being felt. Goldman Sachs has warned of fuel prices rising to 2022 levels. Sustained disruption to global gas supplies could lead to the cap on energy bills in the UK rising by £900 to £2,500 a year.

The UK’s vulnerability to energy price shocks stems from a significant and growing dependency on imports. A recent digest of UK energy statistics (Dukes) report – published annually by the energy department – states that in 2024 the UK got 75.2% of its primary energy needs from fossil fuels, mainly oil and gas. Net import dependency in 2024 was 43.8%, 3.4 percentage points higher than in 2023, and has hovered around the 40% mark since 2010. While growing UK-produced energy resources in the form of renewables, nuclear and batteries, the UK is far from being self-sufficient.

Reports of Starmer’s demise may have been (somewhat) exaggerated

Before the US-Israeli attack on Iran, Starmer’s grasp on power looked increasingly tenuous. He held off a challenge from Andy Burnham by preventing him from standing in the Gorton and Denton byelection, but many MPs were warning that the PM’s days were numbered, some thinking that a disastrous showing in the local elections in May could prompt a Labour leadership race.

But Starmer’s stance on Iran – and his decision not to rush into the war alongside the US and Israel – has been praised by his own MPs and is seen to be in line with public opinion. A YouGov survey this week found that six in 10 Britons were opposed to military action, while a quarter were in favour of it. Emily Thornberry, the Labour chair of the foreign affairs committee, has said the crisis “could be the making of” Starmer.

For now, Starmer’s position seems at least a little more secure, even if that could change again if the results in May look bad for Labour.

Harm to opposition parties

While Starmer has appeared to shore up his premiership for now, other political leaders have at times seemed unclear about their position, which Starmer and Labour have repeatedly tried to capitalise on.

At the outset of the war, the Conservative leader, Kemi Badenoch, and the Reform UK leader, Nigel Farage, supported a closer alliance with the US. Farage said when the conflict began: “We should do all we can to support the operation.”

Badenoch warned the government there was “no point wanting action to make the world a safe place while being too scared to stand by and watch others”. Two days later, she told Labour MPs: “We are in this war whether they like it or not. What is the prime minister waiting for?”

Both have since softened their stance, with Badenoch later saying: “I said that we support their actions. I never said we should join.” Farage has since stated that Britain should not join Trump’s war, saying the military could not “offer anything of value” to America or Israel. Farage held a stunt at a petrol station promising 25p off a litre of fuel and claiming: “If we can’t even defend Cyprus, let’s not get ourselves involved in another foreign war.”

Reflecting on Badenoch’s stance on the war, one senior Tory has said: “We have just looked confused and the messaging has been terrible. But most of us on the right do actually believe Starmer was completely wrong not to support Trump at the beginning, so the right thing to do would be to stick to our guns, whatever the public say.”