The Irish Times view on Trump at the UN: the sound of defiance

US president Donald Trump has addressed the UN general assembly, calling on other nations to "isolate Iran's regime." Video: The White House

The world was laughing at the United States, Donald Trump frequently told his supporters in the 2016 election campaign. It wasn't true then, but it is now. Worse still, it is laughing at him. That was the vignette millions took from Trump's address to the UN general assembly – hundreds of politicians and diplomats breaking into murmurs of laughter as the US president proclaimed his supposed accomplishments with characteristic bombast.

Laughter is humiliating enough. But in the world of big-power politics, being ignored is every bit as bad. And that has been the subtext to the week in New York: US allies, having all but given up on Trump’s chaotic, incoherent presidency, are learning to work around him.

Trump remains the world's most powerful leader. His decisions can still affect world politics profoundly

At the lectern shortly after Trump, French president Emmanuel Macron said the Paris climate accord had survived in spite of Washington's decision to withdraw. Dispensing with diplomatic niceties, he proposed that states should refuse to sign trade deals with those who do not comply with the climate deal. Separately, US allies such as Germany, France and the UK reaffirmed their support for the Iran nuclear agreement, which Trump repudiated in May. With Trump in the chair for Wednesday's security council meeting, the US delegation felt it necessary to change its plan and broaden the agenda beyond Iran so as to avoid the spectacle of every other country lining up against the US president. The leaders of China, Russia and India did not even bother to turn up in New York this week.

Trump remains the world's most powerful leader. His decisions can still affect world politics profoundly. But America's allies are no longer daunted by him in the way they were when he came to office. They have learned to discount his words, knowing he has few fixed opinions and even less knowledge, and is ever liable to change his mind – as his 180-degree turn on North Korea showed – on the most important issues.