The BBC's international editor Jeremy Bowen argues that, despite Donald Trump's aggressive rhetoric, the US president has no realistic alternative to negotiating with Iran. Speaking at a Nato summit in Turkey, Trump called Iran's leaders "scum" and threatened to strike again, yet he also conceded that talks — led by his negotiators Steve Witkoff and Jared Kushner — would continue, even as he dismissed them as "wasting their time". Bowen reads this as an admission that America's military campaign, waged alongside Israel, has failed to break the Iranian regime or force it to abandon its core demands.

At the centre of the standoff is Iran's insistence on retaining control over the Strait of Hormuz, through which around a fifth of the world's oil and gas supply passes, giving Tehran a potential chokehold on the global economy. The regime has been emboldened by surviving the February assault that killed supreme leader Ayatollah Ali Khamenei, and by the strong public turnout at his funeral, though domestic opposition persists after protests were violently suppressed in January. Mediators, who describe the atmosphere as "very tense" and a recent "setback", believe a deal is still possible: it would unfreeze Iranian assets, allow oil sales and acknowledge Iran's authority over the Strait, in exchange for limits on uranium enrichment, the return of UN inspectors and an accounting of already-enriched stocks.