WASHINGTON — The early story line about President Trump and French President Emmanuel Macron focused on their "bromance" and Trump's puerile claim to dominance when he brushed what he said was dandruff off Macron's suit.

But on the last day of his state visit on Wednesday, Macron showed he will not be trifled with. He used a speech to a joint session of Congress to engage in a full-scale takedown of Trumpism, wrapped in a love letter to the United States and a call on Americans to live up to the values embedded in our own history.

Macron, speaking forcefully in English, held nothing back. He warned against "the illusion of nationalism" and politicians who "play with fears and angers." He brought home the nature of the menace by alluding to the U.S. president who led the war against fascism. "The only thing we have to fear ... is fear itself," declared Macron, channeling Franklin D. Roosevelt.

Macron predicted that, despite Trump's abandonment of the Paris Climate Accord, the United States would one day rejoin it. Turning Trump's signature campaign theme on its author, the French president issued his patented call to "make our planet great again." For good measure, he pointedly asked climate change deniers to confront the consequences if they proved to be wrong. "Let us face it," Macron said, "there is no Planet B."

"What is the meaning of our life, really, if we work and live destroying the planet, while sacrificing the future of our children?" Macron asked.

If Trump underscored his permissive attitudes toward autocracy by referring on Tuesday to Korean dictator Kim Jong Un as "very open" and "very honorable," Macron spoke of the obligation to stand up for democracy and against authoritarian threats across the globe. And he reminded his American listeners that the chief architect of the multilateral institutions defending democratic ideals was — the United States of America.

"The United States is the one who invented this multilateralism," Macron said. "You are the one now who has to help to preserve and reinvent it."

"What we cherish is at stake," he added. "What we love is in danger."

He announced flatly that France would not leave the nuclear deal with Iran, and suggested a U.S. withdrawal from the agreement would be counter-productive.

But on this question, he offered a path to conciliation by insisting that he, too, wanted to prevent Iran from ever having nuclear weapons. He proposed a bigger and more comprehensive pact built on the old one. Perhaps Macron has a chance of persuading the administration to take this off-ramp, since anything that seems big or bigger evokes a Pavlovian reaction from Trump.

Again and again, the French leader took on the policies Trump has pursued over the last 15 months. "Massive deregulation," which is what Trump has been up to, is a bad idea, Macron said. The founder of a new down-the-middle French political party may well be a centrist, but he held nothing back in assailing "the abuses of globalized capitalism" and "financial speculation." He also urged joint American-European regulation to protect the users of social media.

And he put all he said in the context of a thoroughly Gallic nod to rationality. "Without reason, without truth," he said, "there is no real democracy."

Macron's speech here came in the wake of his vigorous address last week to the European Parliament in defense of democracy ("Faced with the authoritarianism which surrounds us on all sides, the answer must not be authoritarian democracy but the authority of democracy"). Read in tandem, the two addresses make clear he has decided that his path to history lies in an unambiguous stand against the global influence of right-wing nationalism and the spread of autocracy.

Macron's vigor on Wednesday provided evidence that this mission takes priority over his quest to create a comradely relationship with Trump and to prod him toward less damaging policies.

But since Trump is Trump, Macron might get away with playing both roles at once. He has been so successful to this point as a Trump flatterer that the president described him as "perfect." And on Iran, the White House may come to see that it needs at least a temporary reprieve to concentrate on talks with North Korea, which Macron was careful to endorse.

Still, the French president said last week that in light of the many forces undermining democracy around the world, he did not "want to belong to a generation of sleepwalkers." On Wednesday, no one missed his sense of urgency.

E.J. Dionne's email address is ejdionne@washpost.com. Twitter: @EJDionne.