The deal was never going to hold. Not with Trump. Not with Tehran. But the speed of the collapse still caught Whitehall off guard.
Talks between the US and Iran, already on life support, have flatlined. Washington walked away without warning its closest allies. No heads-up to London. No briefings to Paris or Berlin. The message from the State Department was cold and functional: 'We reassessed our position.' Translation: we don't care about your interests.
For Britain, this is a moment of reckoning. The diplomatic architecture that propped up the JCPOA is now a smouldering wreck. Iran will accelerate its nuclear programme. The region will tip closer to conflict. And the UK, stripped of the EU's institutional weight, is left holding a very fragile piece of paper.
Senior Whitehall sources tell me there is quiet fury in the Foreign Office. Not at the Iranians, but at Washington. One diplomat described the US exit as 'a betrayal of trust so reckless it borders on malice.' He meant it.
Here is the reality. Britain cannot rely on America as a predictable partner in the Middle East. Not with this president. Not with this foreign policy chaos. If we want a deal to hold, we have to lead the charge ourselves.
That means picking up the phone to Tehran directly. It means convening a new, smaller group of willing partners without waiting for US permission. It means using the UK's unique leverage: our financial system, our intelligence links, our seat at the UN Security Council.
The Prime Minister's team knows this. But will they act? The talk in No. 10's corridors is cautious. 'We don't want to be seen as going rogue,' one aide told me. But caution is a luxury we can no longer afford.
Backbenchers are restless. A group of senior Tory MPs, including former defence ministers, is already drafting an amendment demanding a more independent UK foreign policy on Iran. The whip's office is worried. They should be.
Labour is watching too. Starmer's team sees an opening to paint the government as a US poodle. The charge is unfair, but it will stick if No. 10 does not move soon.
Polling data tells the story: British voters want action. A majority now favour direct UK-Iran negotiations, even if the US objects. The public has lost patience with being dragged into America's impulsive retreats.
So the question is not whether Britain should lead. It is whether Downing Street has the nerve to do what Washington will not. The answer, at this moment, looks dangerously uncertain.
The deal is dead. The allies are exposed. And the responsibility falls squarely on our shoulders. Britain must step up before the whole house of cards comes crashing down.
