The war in Iran may finally be coming to a close. After so many false starts, at last a deal appears imminent: one that, as Donald Trump boasts, will end both the conflict, which started in February, and with it the mullahs’ hopes of acquiring a nuclear weapon.

Not everyone is on board. A senior member of Iran’s parliament loftily dismissed it as a ‘wish list’, while surviving members of the leadership continue to vow defiance – a stance they generally maintain right until they U-turn and compromise.

For all that, my hunch is that a deal will happen sooner or later – simply because all the parties need one.

The Iranian regime is desperate for some respite after the hammering it has taken.

The Trump administration wishes to call an end to a war that has gone badly, that has spiked domestic inflation and that remains hugely unpopular among ordinary Americans – with midterm elections just six months away.

Meanwhile, the whole world needs the Strait of Hormuz to reopen so that supplies of Middle Eastern oil and gas can resume and the cataclysmic energy shock that is swiftly unfolding can be mitigated, if only in part.

So from the White House to the mullahs’ bunkers, from Beijing to Islamabad, policymakers will be congratulating themselves on having pulled things back from the brink.

They are entirely wrong to do so. This is not a moment of catharsis: instead, it’s one of great sadness.

Why? Well, firstly, because of the nature of the deal itself. What is now on the table, after all the billions spent and the thousands slaughtered, is essentially a stripped-down version of Barack Obama’s 2015 Joint Comprehensive Plan of Action (JCPOA), from which Trump petulantly withdrew in 2018 during his first presidential term.

Under the new American proposals, Iran would cap its enrichment of uranium below 4 per cent: levels suitable only for civilian power generation. Its stockpile of enriched uranium would, meanwhile, be diluted or exported. There would, too, be tougher inspections, limits on the advanced centrifuges required to produce weapons-grade uranium and a freeze on enrichment for perhaps 15 years.

In return, the US would ease sanctions on Iran, unfreeze billions in assets and, we must assume, end its attacks.

In essence, it’s JCPOA II – only not as ambitious as the first time round.

All that’s depressing enough. Then there’s what’s not in the deal. No meaningful limits placed on Iran’s regional mischief through its terrorist proxies, Hamas and Hezbollah. No restrictions, it seems, on the mullahs’ most fearsome existing military threat: their ballistic missiles, which – incredibly after the punishment they have suffered – they still boast in considerable numbers.

And worst of all – despite Trump’s hollow promises to help the Iranian people to ‘rise up’ and overthrow their masters – no pressure on Tehran to improve its record on human rights.

Some 30,000 innocent Iranians are now thought to have died resisting the authorities’ sordid violence since January alone. Their sacrifice, it seems, is in vain.

This week, I managed to reach a contact inside the country I’ll call ‘Ibrahim’. We had corresponded in the early days of the war, then he went quiet. I worried the regime had murdered him.

But he is alive. And the picture he paints is bleak.

‘At the start of the war, we though that – at last – this was going to be the end of the regime,’ he told me. ‘When [Ayatollah Ali] Khamenei was killed [in an air strike on February 28], we celebrated. Now we worry the West will give up on us – just when it should be trying to help us finish the job.

‘Believe me, David, they [the regime] are weak. People here worry that a deal with the Americans means the Islamic Republic will survive. The authorities are killing more every day. They’re even worse now than they were before the war.’

What strikes me most is Ibrahim’s fear – not of the Islamist blackshirts prowling his neighbourhood, not of arbitrary detention or even torture – but that we, the Free World, have abandoned him.

That the struggle of Iran’s people, who have repeatedly taken to the streets only to be gunned down, seized and disappeared, will be forgotten. That he, and so many like him, will be abandoned. And that the mullahs, once again, will have won.

I wish could tell him that he is being paranoid. That after everything Trump promised, the West would never desert the Iranian people. But I can’t lie to him. From the Afghans to the Kurds, I’ve seen us turn away from erstwhile allies too many times.

Much has been made of America’s many missteps in its pursuit of this war. Emboldened by his surgical removal of the Venezuelan dictator Nicolas Maduro –now languishing in a Brooklyn jail cell – back in January, Trump acted hubristically and without a proper plan.

He didn’t get his allies on side (and, yes, Nato is certainly weaker after this war). He didn’t get the American people behind him, either – having repeatedly promised them ‘no more wars’ – and has hamstrung his domestic agenda as a result.

All true. But, let’s be clear, Trump’s broadest objective – regime change in Iran – was a noble one, even if it was impractical, hasty and unrealistic in the allotted time.

Yet however justified the aim ultimately was, I could have told Trump, his ludicrous ‘Secretary of War’ Pete Hegseth and the rest of the ghouls in the West Wing that there will be never be meaningful regime change in Iran without an organised opposition – and, crucially, without a proper alternative leadership. And neither of those exist.

I have met Reza Pahlavi, the exiled son of the late Shah, who is in some quarters Iran’s favourite caretaker leader should the mullahs one day fall.

He is pleasant enough but, having spent half a century living in luxury in Maryland, he is basically American now: strangely unworldly for all his heritage, and effete like so many of the ultra-wealthy. He would be eaten alive in his homeland.

Back in Iran, all domestic opposition has been crushed. And so without a credible alternative to the mullahs, what you will be left with – in the event that they do one day fall – is instability. And in a country as complex, as fractured, as Iran, that will lead not to democracy but to chaos, or even civil war.

The sheer wretched state of the nation only seems set to get worse. Almost 50 years after the revolution, the story of Iran is thus one of the most sustained human tragedies on the planet.

I am half-Iranian: my maternal family fled the country in the 1970s, as the black stain of Islamism began to spread across our country. My relatives foresaw what was coming before many others did: the slow, suffocating takeover of an ancient nation by a genocidal theocracy.

I was born in 1982, soon after the revolution. But to this day, my mother’s family dream of returning.

‘Next year in Tehran,’ we say to one another. ‘Next year in Tehran.’