Taken together, the two men defined the dramatic change in American foreign policy that has left the traditional allies who gather at the Munich Security Conference in despair, and has led the Trump administration to embrace newer, far more authoritarian allies in Central Europe. Mr. Pence and Secretary of State Mike Pompeo spent the week visiting several of them, in a European tour that bore little resemblance to similar trips taken by administrations past.

“The contrast is between a new foreign policy that focuses on America first and expects others to do as we say no matter what,” said Ivo Daalder, a former American ambassador to NATO and now the president of the Chicago Council on Global Affairs, “and the old foreign policy of working together in pursuit of common values.’’

Mr. Pence did acknowledge significant progress in getting more NATO members to live up to their commitment to contribute 2 percent of their gross domestic product to defense by 2024. Even the current secretary general of the NATO alliance, Jens Stoltenberg of Norway, said on Saturday that “European allies are stepping up more for defense.”

But Mr. Pence went further.

He repeated a call that he made in Warsaw on Thursday, during an American-led conference of foreign ministers chiefly from Arab and European states, that Britain, France and Germany withdraw from the 2015 nuclear accord with Iran.

It was a demand they had no intention of complying with, as Chancellor Angela Merkel of Germany made clear in an impassioned defense of alliances and Europe’s approach to Iran that preceded Mr. Pence’s speech by only moments.