The most likely explanation of his actions, which have provoked a crisis in the region (and pushed Qatar into the arms of Iran) is that the Saudis flattered him — the Ritz-Carlton projected a five-story image of his face on the side of its Riyadh property — and their lobbyists spent large sums at the Trump Washington hotel.

Normally, we would consider it ridiculous to suggest that an American president could be so ignorant of crucial issues, and be led to take dangerous foreign policy moves with such crude inducements. But can we believe this about a man who can’t accept the truth about the size of his inauguration crowds, who boasts about his election victory in the most inappropriate circumstances? Yes.

And consider his refusal to endorse the central principle of NATO, the obligation to come to our allies’ defense — a refusal that came as a shock and surprise to his own foreign policy team. What was that about? Nobody knows, but it’s worth considering that Trump apparently ranted to European Union leaders about the difficulty of setting up golf courses in their nations. So maybe it was sheer petulance.

The point, again, is that everything suggests that Trump is neither up to the job of being president nor willing to step aside and let others do the work right. And this is already starting to have real consequences, from disrupted health coverage to ruined alliances to lost credibility on the world stage.

But, you say, stocks are up, so how bad can it be? And it’s true that while Wall Street has lost some of its initial enthusiasm for Trumponomics — the dollar is back down to pre-election levels — investors and businesses don’t seem to be pricing in the risk of really disastrous policy.

That risk is, however, all too real — and one suspects that the big money, which tends to equate wealth with virtue, will be the last to realize just how big that risk really is. The American presidency is, in many ways, sort of an elected monarchy, in which a temperamentally and intellectually unqualified leader can do immense damage.

That’s what’s happening now. And we’re barely one-tenth of the way through Trump’s first term. The worst, almost surely, is yet to come.