Trump’s endorsement of trans-Atlantic cooperation came after a week in which he attacked the mayor of London as a “stone cold loser,” called for a no-deal Brexit that could weaken both Britain and the European Union, and said he favors a wall, or at least a hard border, between the Irish Republic and Northern Ireland, which could undermine peace there.

The strength of Trump’s speech here was that, in the style of Ronald Reagan, he evoked the personal lives of the D-Day veterans assembled behind him on the podium. For once, he wasn’t telling his own story, but that of America and its allies. “More powerful than the strength of American arms was the strength of American hearts,” he said. It was a great line, but one that many would find dissonant with Trump’s saber-rattling nationalism.

Trump seemed to understand that this site, with its forest of white crosses, assembled like a silent army at perpetual rest, may be the most important stage on which an American president can play.