On March 30, Nikki Haley, the United States’s ambassador to the United Nations, said: “our priority is no longer to sit there and focus on getting Assad out.”  Today, she will say: “There’s not any sort of option where a political solution is going to happen with Assad at the head of the regime”.  Haley speaks for America’s Government and its President.   What has happened in less than a fortnight – indeed, in a single day – to cause him to U-turn not only on Assad, but on the foreign policy approach on which he fought the Presidential election?

The obvious answer is the Syrian regime’s use of chemical weapons in an attack on Khan Sheikhoun.  But it has used them before in 2013, with effects no less horrific than last week’s.  That time round, Trump tweeted “President Obama, do not attack Syria. There is no upside and tremendous downside. Save your ‘powder’ for another (and more important) day!”  Why the change?

It may that the solution lies in the turmoil within the President’s administration.  Evidence of a power struggle is all over the media daily, the main protaganists being Reince Priebus, Trump’s Chief of Staff; Steve Bannon, his Chief Strategist, and Jared Kushner, his son-in-law.  Priebus is a chip off the Republican establishment; Bannon a force for Breitbart-style politics, and Kushner (together with Ivanka Trump, the President’s daughter) essentially a centrist. One report today claims that Preibus has told Bannon and Kushner to “bury the hatchet”.  Another suggests that the Ivanka helped to persuade her father to change his mind on Syria.  Both could be true.  Or neither.  All that is certain is that public feuding and briefing of this intensity so early in a presidency is unusual if not unprecedented – and that having such incompatible worldviews near the top is uncommon, too.

One version of events is that this is the way that Trump likes to work, and that these inconsistencies and contrarieties are not so much harmful as actually helpful to him.  The logic of this position is that those around him scrabble in a Darwinian struggle for his ear and heart, while he soars above them making his eventual decisions in the unpredictable and intuitive way that marks him.

Perhaps that view is right.  But if so, it ought to give Conservative MPs pause for thought.  As we write, they are in their constituencies or working elsewhere or on holiday until the Commons resumes on April 18.  This morning, they will be reading what the rest of us are reading: namely, that the Government is swinging behind the long-held view in parts of Westminster and Whitehall that there must be regime change in Syria.  “Assad must go,” Michael Fallon writes in the Sunday Times (£).  Boris Johnson has called off his planned visit to Moscow, and is reported now to be fronting the familiar policy of seeking to work with Russia to dump Assad, which Downing Street and the Foreign Office are reviving.  This approach envisages America and the G7 putting pressure on Russia to join them and, in turn, put pressure on Syria’s regime to dump Assad.

Under this plan, he would presumably be shuffled off to a villa somewhere by the Black Sea, while a government of national unity is formed in Syria, consisting of moderate rebels, elements of the present regime and mainstream Muslims (who are represented in both groups, along with religious minorities in the last one).  The jihadists would be frozen out altogether.

This is not a perfect scheme, since Assad and some members of his regime would presumably escape trial for war crimes, but this is not a perfect world.  What matters most is bringing peace and security to horror-engulfed Syria, which this proposal would have a chance of doing.  However, those Tory MPs will have ponder the same problem that you have already spotted: namely, that it has been pushed before, and Russia has rejected it.

Perhaps it will be different with Trump rather than Barack Obama in the White House.  But maybe it won’t.   And perhaps Trump himself doesn’t have the patience to work away at trying to make it happen in any event.  It may be that he will mull military options instead.  Conservative MPs will ponder the history of military intervention in Iraq and more recently in Libya – or should do.  They will ask whether it would be wise to back action which could see the evils of the Assad regime replaced by the evils of a jihadist one.

For after all, the latter would be the most likely beneficiaries of Assad simply losing the present war, rather than being replaced as part of a negotiated peace.  The Sunni jihadists in Syria stretch from ISIS through Al Qaeda affiliates to others who change names and allegiances so fast that it is almost impossible to keep up with them.  Theirs is the ideology that inspired 7/7, the murder of Lee Rigby, the recent attack on Westminster Bridge, the terror assaults in Paris and Belgium – and last Friday’s murders in Sweden.  They are the immediate threat to our national security, not the growth of Iranian power abroad.

If the answer to our question of who is in charge in the White House is an impulsive president with no consistent plan, Tory MPs will want to reserve their options.  At present, our Government and others seem to be seeking to channel his energies into a plan that has every advantage bar the one of being clearly deliverable.  It’s worth trying again.  But given Trump’s unpredictability, and British governments’ history of tagging along with America, for both good reasons and bad, they should be picking up their phones and making their concerns known to the whips.