One may be forgiven for thinking that Donald Trump and Emmanuel Macron are in love. Their remarkable body language—the air kisses, the back pats, the hand-holding, the dandruff brushing—has been the talk of the town on Macron’s state visit to Washington. But after listening to the French president’s speech to Congress on Wednesday, a question arises that could have enormous geopolitical consequences. What happens if the love of the mercurial American president turns to hate?

Does Trump understand how often Macron dissed his isolationism and exaltation of ignorance before the largely enraptured American legislators? (There were so many standing ovations it started to look like calisthenics.) Does Trump, who is always jealous of attention, and who demands unquestioning loyalty from the people around him, not see how powerfully opposed to his policies on trade, on the Iran nuclear deal, on climate change Macron really is?

Macron’s de rigueur opening joke was about Voltaire and Benjamin Franklin embracing and kissing, which “can remind you of something.” He then went into a long panegyric about the shared history of France and the United States during the American Revolution, World War I and World War II, talking about “the continuity of our shared history in a troubled world.” (Forgotten, it seems, are the “freedom fries” and the snarky American denunciations of “cheese eating surrender monkeys” when the French dared to oppose the U.S. invasion of Iraq as an act of monumental stupidity.)

Macron’s talk about the democratic values of the West and its commitment to freedom were not boilerplate, but a direct response to the know-nothingism and ultra-nationalism resurgent in the 21st century, 70 years after World War II. “Both in the United States and Europe, we are living in a time of anger and of fear,” he said. And who has profited more from that than Trump?

“Closing the door to the world will not stop the evolution of the world,” Macron warned. “We have to keep our eyes wide open to the risks right in front of us.” Among them, “rampaging nationalism.”

On climate change, which Trump finds it politically expedient to question, Macron repeated one of his own favorite aphorisms. “We are killing our planet. Let us face it. There is no Planet B.” And then, riffing on Trump’s trademark slogan: “Let us work together to make our planet great again in order to create new jobs and new opportunities.” (That prompted one of many standing ovations.) Macron even held out hope that the United States—he didn’t say Trump—might rejoin the climate accord.

On Iran and Syria, Macron repeated the same points he had made at a press conference Tuesday: Keep the Iran nuclear deal, and then cut new deals on missiles and on what happens when the original deal expires, while using military force to block the Iranian boots on the ground in Iraq and Syria—which the U.S. must not leave before “as soon as possible” is possible.

If Macron were telling Trump something significantly different in private than in public, that might explain Trump’s more than affectionate tolerance. But Macron is a fan of the French Nobel Prize laureate André Gide (a close friend of Oscar Wilde) who penned the famous aphorism: “It is better to be hated for who you are than loved for who you are not.” And of the many criticisms that might be leveled against the imperius French head of state, inconsistency should not be one of them.

No, the real danger here is that Trump is so taken with Macron’s flattery and pseudo-filial affection that he hears only what he wants to hear. Love is not blind, but it is blinding, and when the moment of revelation comes the consequences can be catastrophic. Let’s hope that is not the case.

UPDATE: On Wednesday evening, Macron told a small group of reporters he did not think he had managed to convince Trump to hold on to the Iran deal. Macron said he had tried to play the "honest broker," giving the American president his best evaluation of the situation, but Trump almost always reverts to positions he knows play well with his base. "When a lot of people say Trump isn't predictable, I think the opposite," said Macron. "He is very predictable."