So much for the idea that President Trump would be too ignorant and coarse to conduct diplomacy with Europe on a grand scale. And that he can’t handle differing points of view.

The state visit of President Macron of France makes clear that Mr. Trump has found a European partner of verve and vigor. And that he can work with someone who is well to his left.

This started coming into view for millions of Americans at Tuesday’s state banquet. First Lady Melania Trump laid on an elegance worthy of Jackie Kennedy, and the two presidents exchanged classic toasts.

The startling thing was the next morning, when Monsieur Macron delivered a speech to a joint meeting of Congress, in which he laid out his differences with Mr. Trump on global warming and Iran.

Republicans gave him a warm and noisy welcome. The Democrats, though, were faster to their feet, cheering as Mr. Macron needled Mr. Trump over the Paris climate accord and the Iran deal.

No cheese-eating surrender monkey ever got a better reception. And the astonishing thing is that Mr. Trump seemed to take it all in stride (he said in advance Mr. Macron would do a great job).

What a contrast to the last time the leader of a major foreign ally criticized an American president’s program before a joint meeting of Congress. That was Prime Minister Netanyahu of Israel.

Remember? Messrs. Netanyahu and Macron both went to the Hill with a similar message — the sitting president was about to mishandle a deal with Iran. Mr. Netanyahu warned against signing President Obama’s pact with the ayatollahs, while Mr. Macron wants to save, not kill, the deal, and is pushing “improvements” that run against Mr. Trump’s instincts.

How did the two American presidents react? Mr. Obama went into a first-class tantrum, carrying on about how Congress was wrong to invite Netanyahu in the first place and deriding Mr. Netanyahu personally.

Mr. Obama reduced his Israel relations to a shambles. He went ahead and inked the Iran deal against what the New York Times has described as “overwhelming” opposition in Congress.

While the Israeli leader focused on only a narrow issue — the Iran deal — Mr. Macron issued a broader challenge to his host, starting with a call for a “new breed of multilateralism.” How does one say “chutzpah” in French? Mr. Trump just won the presidency in part on his beef with multilateralism.

That is, with institutions like the United Nations, the European Union, NATO, and various free-trade agreements. Mr. Trump has made it clear he prefers bilateral relations and doesn’t want America fleeced.

Then Mr. Macron carped about Mr. Trump’s opposition to the Paris climate accord, a scheme to pick Americans’ pocket. Mr. Trump pulled out of it less than a year ago, citing its costs.

Yet, Mr. Macron told Congress, “some people” — Trumpists, he meant — think that securing jobs is “more urgent than transforming our economies.” He said he wanted to “make the planet great again.”

Mr. Macron was particularly obnoxious on Iran. He wants to expand the deal to cover “four pillars” — the current pact, plus “the post-2025 period,” regional military influence and monitoring ballistic missiles.

None of Mr. Macron’s pillars mentioned democracy in Iran or an end of its war against Israel. He’s prepared to contract with an anti-Semitic, non-democratic, theocracy constitutionally committed to jihad.

Which brings us back to Mr. Trump. He’s in a perfect position to withdraw from the Iran deal when the deadline comes up next month, while saying he’ll look at any improvements Mr. Macron can get.

For that matter, Mr. Trump could do the same with the climate pact. If Mr. Macron thinks he can get a fair deal for America that’s in accord with the “science,” let him try.

Meantime, Mr. Trump has found a partner in the heart of Europe — a leader who started out, like Mr. Trump himself did, as a businessman. And who brushed aside the old guard, right and left, to win his presidency.

Mr. Macron declined to get drawn into complaining about Mr. Trump’s fitness. He welcomed Mr. Trump in France and has been markedly more friendly than the other European leaders.

Including, incidentally, the British, who’ve yet to assure Mr. Trump a warm welcome in London. Then again, France sided with us in the Revolution. Old habits die hard.

This column first appeared in the New York Post.