As the drums of war beat ever more loudly in the Gulf and it became inconceivable that the US would assemble such a huge concentration of firepower in the region not to use it, I asked in these columns what the purpose of an attack on Iran would be.
To make it impossible for Iran to build a nuclear arsenal? To degrade and destroy its missile stockpiles and production capabilities? Regime change?
Turns out it's all of the above - and more.
Donald Trump has added a fourth war aim: no more financing and arming of the Iranian proxies - Houthis, Hamas, Hezbollah and others - which have for decades spread terror across the Middle East and beyond.
It's quite an agenda, and who can doubt the Middle East and the wider world would be better places if Trump could achieve it?
The threat of a nuclear-armed Iran removed. No more indiscriminate lobbing of missiles at Israel when it feels like it. The crippling of some of the world's worst terrorist groups.
The demise of an evil, repressive mediaeval theocracy. The prospect of a post-Islamist Iran no longer intimidating its neighbours but living alongside them in peace and prosperity.
So, the prize is huge.
We should wish Trump well in his endeavours and hope for a speedy and successful conclusion.
The question is whether any of it, never mind some of it, can be achieved only from the air - which seems a stretch.
Other than clandestine interventions by special forces, specific and limited in nature, I'm pretty sure - whatever Trump claims -there is no possibility of Israeli or American boots on the ground.
But what happens if, even after the regime's top brass has been decapitated and its infrastructure of repression degraded, the regime is still intact and the people have not risen up to throw off their oppressors. What does Trump then do?
Supreme Leader Ayatollah Khamenei was killed in the first wave of strikes. Trump claims that up to 50 regime leaders have also been dispatched, including such top-echelon figures as the head of the Revolutionary Guard, the military force which props up the mullahs, the defence minister, the head of the armed forces and the head of the national security council.
It is a grim but impressive harvest of some of Iran's most senior leaders in only a few days. Yet the regime continues to function, continues to fire indiscriminately at nearby Gulf States and beyond (even as far as our RAF base in Cyprus), continues to snuff out dissent.
This was never going to be a dictatorship which toppled just because you got the top man, more's the pity. It has depth, reach and plenty of replacements to call on.
Nor is there any organised opposition for protesters to rally round. Prominent dissidents are far away in exile.
People have been understandably intimidated by the mass slaughter of activists during the recent uprising, the full scale and horror of which has yet to be revealed. They will need proof the regime is on its last legs before they take to the streets again.
Nor does the US's failed record of regime change give cause for hope.
Multiple commentators, especially on the Left, see the current attack on Iran through the prism of the invasion of Iraq in 2003 - a disastrous military intervention whose failure cast a dark shadow over the Middle East for years after, while undermining the authority and integrity of the US and its allies in ways which still haunt us to this day.
So, I understand why people are wary. I'm wary, too.
Once again, we have a US President talking about weapons of mass destruction and regime change. What could possibly go wrong? Are our leaders determined not to learn the lessons of history?
But sometimes the wrong lessons are drawn. While Iraqi dictator Saddam Hussein had no WMD despite what we were assured by the US and Britain before the invasion, there is very little doubt Iran has been trying to develop a nuclear bomb and would do so if left unhindered. That would be catastrophic for the Middle East and the world.
But Trump, thankfully, shows no inclination to assemble an invading army to thwart it; has zero interest in nation building unlike President George W Bush and his Vice-President Dick Cheney—the duo who took the US to war in Iraq.
I am also sure—and this is not widely enough realised—what Trump means by regime change is very different to what those two meant.
They meant taking over a country and pretty much forcing democracy on it. Trump couldn't care less about that.
Look at what he's done in Venezuela. Yes, he removed its anti-American dictator, Nicolas Maduro (who now awaits trial in the US), but he didn't hand over power to the opposition (and unlike Iran, there is one in Venezuela - indeed it recently won an election which Maduro ignored).
Instead, he handed over power to Maduro's deputy, who has proved more compliant in meeting Trump's wishes than her former boss.
Faced with a choice of democratic forces with their own agenda and a dictator who would do his bidding, Trump chose the dictator. Not so much regime change, more regime reconstruction.
Of course, you could see it as an interim stage on the way to more democracy. But if Maduro’s successor gives Trump all he wants, I wouldn’t hold your breath—and I’m pretty sure this is the template for what Trump means by regime change in Iran.
Not the flowering of democracy in Tehran but the search for Iranians in the current regime and beyond prepared to abandon its brutal proxies, its nuclear ambitions, its long-range missiles and its obscene mission to wipe out Israel.
That they would still preside over an authoritarian government would not be, for Trump, a dealbreaker.
Now such a prospect will cause a fit of the vapours in polite western society.
To be honest, it doesn’t fill me with enthusiasm either. But it might be more realistic, stand more chance of success, lead to a more harmonious Gulf region than the failed Bush-Cheney approach.
Remember, there are no democracies in the Gulf. Just a collection of dictatorships, mostly pro-American (they were pretty pro-British too when we mattered there), some more benign than others, some more repressive. Why should Iran be any different?
The risk is not that it might happen - but that Trump won't hang around for long enough to make it happen. That he won't stay the course to bring about the change. His attention span is notoriously short; his appetite for prolonged military adventures zero.
He lives by quick results and speedy solutions.
We need to see this in a wider context. The 21st century so far has been dominated by hardline autocrats’ march. An anti-West axis of autocracy has had too much of its own way for too long.
Trump is at last giving it a bloody nose—first in Venezuela; now Iran; perhaps very soon Cuba too. China and Russia—the axis’s big brothers—have proved powerless to help.
It’s not ideal; it’s certainly not idealistic. It would be better if there were another way. But there isn’t. We live in a new age of realpolitik. We need to hold our nose and come to terms with that.
For the prize is worth it: a Middle East far from perfect but so much better than what we have now. So stay the course, Mr President.