Having walked away from one plan, he promised another. His Secretary of State was meant to spell it out this week.
We were given a wish list. Iran must do everything America demands. Get out of Yemen, get out of Syria, stop developing ballistic missiles and promise never to build the bomb. Or else.
It’s the “or else” bit that still has us guessing. Mr Trump has already promised the toughest sanctions the world has ever seen, or something like that and his hawkish secretary of state repeated the threat.
But sanctions only work if imposed in concert with your allies and often not then.
Mr Trump has studiously offended and alienated America’s closest allies by deserting the Iran deal, the Paris Climate Change deal, the TPP trade deal and recognising Jerusalem as capital of Israel.
The Europeans are in a sulk and not in any mood to back Trump on Iran.
Instead the White House is indulging in a good deal of wishful thinking and making thinly veiled military threats.
Mike Pompeo stopped short of saying the words. They are still unfashionable in Washington. But it is clear what the Trump administration wants in Iran is regime change.
They have been encouraged in this fantasy by the Iranian opposition group MEK which has in the past given financial support to key figures in Mr Trump’s team. In the same way as Iraqi opposition figure Ahmed Chalabi pulled the wool over the Bush administration’s eyes in the run up to the invasion of Iraq, Trump’s Iranian advisers are giving his people an equally blinkered view of Iran.
The Trump administration appears also to have become overly excited by the unrest in Iran at the start of the year. It was widespread and harder to suppress than the regime may have initially estimated.
But there is no reason to believe the regime is in a way threatened by the protests even if coupled with the toughest of unilateral US sanctions.
One veteran Israeli observer who knows the region better than most told me last week the idea that the regime is close to being toppled is fanciful.
There remains the possibility that Iran reverts to its old ways and tries to build the bomb and thereby gives the Trump administration and Israel the excuse to punish it with military action that could in turn bring down the ayatollahs.
If that is in the back of planners’ minds in the Pentagon and White House, then the lessons of Iraq have clearly not been learned.
If there is no compelling logic behind Donald Trump’s policy on Iran and he has no effective alternative plan, is something else motivating him? Poor advice, almost certainly, peddled by vested interests in Israel, Iranian opposition figures and Iran’s enemies in the Gulf.
And no doubt the same spiteful contempt for anything his predecessor achieved.
Another key part of Barack Obama’s legacy is being taken apart without an effective replacement creating greater uncertainty and instability in a region that already has more than it needs of both.