"Better together.” That’s the optimistic theme that Annalena Baerbock, the new president of the United Nations General Assembly, chose for this year’s global gathering, the 80th. U.S. President Donald Trump instead confirmed in his speech what I keep hearing from the cognoscenti here at UNGA: The likelier trajectory points toward "worse apart.”

As is his wont, Trump heaped contempt on the U.N. as on other countries and people he disdains. "The two things I got from the United Nations,” he sneered, are "a bad escalator and a bad teleprompter.” (Apparently, neither device worked to his satisfaction.) And while he, the peacemaker-in-chief, was allegedly out ending seven wars, "sadly, in all cases, the United Nations did not even try to help.”

This is today the sound of America — the co-founder, host and eight-decade underwriter of the U.N. system — eating its children like Cronus. And the stony faces and occasionally audible gasps are those of the assembled world dreading the fate of what diplomats call the "international community minus one.” The U.S. may or may not exit the U.N. as it once orphaned the League of Nations. But it’s bad enough that America has morphed from the system’s main benefactor into its spoiler.