No one can say how the remainder of the meetings will go, or what will happen after he leaves. But everyone seemed determined to avoid the sort of blowup that marred last year’s Group of 7 meeting in Canada, when a stormy Mr. Trump refused to sign the final communiqué and lashed out at the host, Prime Minister Justin Trudeau.

“Thus far, this has been really a great G-7,” Mr. Trump gushed on Sunday, “and I want to congratulate France and your president because they have really done a great job.”