“I WANT us to be honest with one another,” a new leader on the national stage said Thursday. “We’re on the same team. We share the same mission. Honesty will undergird our foreign policy, and we’ll start by making it the basis of how we interact with each other. . . . Let us extend respect to each other, especially when we may disagree.” The leader in question was Secretary of State Rex Tillerson, and his audience consisted of State Department employees assembled at Foggy Bottom to meet their new boss.

Wise as they were, Mr. Tillerson’s comments stood out for their rationality and evenhandedness only because they were uttered amid the rapid deterioration of such formerly commonplace standards of political culture. The president of the United States, in particular, continues to operate according to a different standard: insulting allies, intimidating civil servants, improperly threatening recipients of federal funds. Such behavior can only hurt the United States’ standing and undermine the peace abroad while damaging democratic norms at home.

Mr. Tillerson’s remarks may reassure State’s professionals, who were told by President Trump’s spokesman to “get with the program” or quit after hundreds of them signed a letter of dissent over Mr. Trump’s harsh executive order on immigration. Alas, cleaning up after Mr. Trump could be a full-time job for Mr. Tillerson; the president’s penchant for verbal excess apparently extends even to the prime minister of a close ally, Australia, with whom he had cross words on the phone the other day. He followed that gratuitous clash with a tweet berating a U.S. commitment, inherited from the Obama administration, to resettle up to 1,250 refugees at Australia’s request as a “dumb deal.” Closer to home, the University of California at Berkeley attempted in good faith to give right-wing provocateur Milo Yiannopoulos an opportunity to speak — and to give peaceful opponents an opportunity to protest — on its campus. When violent interlopers spoiled the peace with arson and vandalism, Mr. Trump bizarrely blamed the school and threateningly tweeted: “If U.C. Berkeley does not allow free speech and practices violence on innocent people with a different point of view — NO FEDERAL FUNDS?” Even if Berkeley were at fault, federal grants are not Mr. Trump’s to award or withhold on a whim.

It is hard to keep up, but at last check Mr. Trump had treated the audience at the National Prayer Breakfast to musings about low ratings for “The Apprentice” — followed by a defense of his brusqueness toward the Australian prime minister and other world leaders. “Believe me. When you hear about the tough phone calls I’m having — don’t worry about it,” Mr. Trump said. “We’re going to be a little tough, folks. We’re taken advantage of by every nation in the world, virtually.”

This is wrong, spectacularly so. The United States occupies a privileged position atop the world’s power pyramid, and it benefits from well-designed mutual relationships such as the alliance with Australia — relationships that demand constant tending as China aims to expand its influence in the western Pacific region. As Defense Secretary Jim Mattis said in his first message to his department, “Recognizing that no nation is secure without friends, we will work with the State Department to strengthen our alliances.”

Like Mr. Tillerson, Mr. Mattis took the opportunity of his arrival to recognize a brightness in America that Mr. Trump too often misses. “You represent an America committed to the common good,” Mr. Mattis told the uniformed and civilian members of his department and their families, “an America that is never complacent about defending its freedoms; and an America that remains a steady beacon of hope for all mankind.” He was right, but that beacon remains steady only with constant vigilance and work.