PARIS — President Trump will be in Europe on Thursday for the second time in less than a week, having accepted a rare outstretched hand from a leader on the Continent, where he is deeply unpopular.

The invitation by France’s president, Emmanuel Macron, might not only give Mr. Trump a brief respite from his domestic political woes, but also establish Mr. Macron’s standing as Mr. Trump’s primary point of contact in Western Europe.

It’s a position Mr. Macron appears to have fallen into almost by default, as the British focus on their exit from the European Union; Germany’s chancellor expresses open disdain for Mr. Trump; and the southern Europeans remain in perennial fiscal difficulty. But it is also a role that Mr. Macron has assumed with relish: The whiz kid of French politics has a seemingly limitless confidence in his capacity for seduction.

How the relationship will work with Mr. Trump remains to be seen. The invitation by Mr. Macron, at 39, France’s youngest president in modern times, to Mr. Trump, 71, the oldest person ever elected to the White House, is consistent with Mr. Macron’s developing hard-nosed pragmatism in global affairs. It is, however, an unlikely partnership, given Mr. Trump’s professed admiration for Marine Le Pen, the far-right populist Mr. Macron defeated in the May 7 election, and the gulf between Mr. Macron’s technocratic, pro-European and youth-oriented approach and Mr. Trump’s nationalistic, America-first message.