They were laughing at him, and it made President Trump angry. So when asked about the video clip that appeared to show NATO leaders commiserating about Trumpian behaviour, the president was snappish. “Well, he’s two-faced,” Trump barked about Canadian Prime Minister Justin Trudeau (who was joking to counterparts about Trump’s self-promotion).

But Trudeau wasn’t alone in issuing Trump a put-down in England. The open disdain shown by some allies at NATO’s 70th anniversary celebration this week reflects how Trump is regarded worldwide, both by longtime friends and foes.

I have watched the shift in attitudes in my travels since Trump was elected, including to Russia, the Mideast, Europe and a just completed trip to China. The president is seen as erratic, untrustworthy and interested in little beyond self-promotion or making a profit. And oh yes, as easily manipulated by flattery, especially by the autocrats he admires unreservedly.

And so ill-informed that he could unintentionally drag America into a war.

The dangers this presents were well laid out by French President Emmanuel Macron, in an interview with the Economist just prior to the NATO meeting. The French leader said the absence of American leadership was leading to “the brain death of NATO.” He added that America under Trump was showing signs of “turning its back on us”, meaning abandoning its commitment to the alliance, which drastically undercuts the viability of the organization.

Case in point, said Macron, in the interview, was Trump’s pulling US troops out of northeastern Syria, and abandoning our Kurdish allies, with no prior notice to them or to European countries such as France, which also had troops in that theater. “You have no coordination whatsoever of strategic decision-making between the United States and its NATO allies,” Macron said. “None.”

At the meeting, as he met the press alongside NATO Secretary General Jens Stoltenberg, Trump called Macron’s remarks “very insulting.”

Yet over 40 minutes, while questioned repeatedly about his NATO strategy, Trump showed himself clumsily unable to utter one sentence on the topic. No matter what he was asked, he returned over and over to his one talking point: that, thanks to him, NATO members upped their defence spending (although, even on the numbers, he kept making inaccurate claims).

As Macron, pointed out, in a testy public exchange with Trump, NATO has other challenges besides “just numbers.” But Trump seemed not to have a clue or a care as to what NATO should actually do in the future. It was left to Stoltenberg to talk about the need to continue the fight against terrorism and the implications of a rising China. (It is little wonder that NATO members fear Trump might withdraw from the alliance if he wins in 2020.)

As for Trump’s most favoured autocrat, Vladimir Putin, Trump made clear, as he sat with Germany’s Angela Merkel, that he wants to invite the Russian to the G-7 meeting next June. Never mind that Russian proxies still occupy a dismembered Ukraine, and that Russia still refuses to admit its agents poisoned people in Britain or meddled in the US election.

Trump’s NATO appearance solidified the image of a US president bereft of any long-term strategy towards Europe, Russia or China who (falsely) believes the world agrees is a “stable genius.” Instead, world leaders see Trump as abdicating America’s historic role while Russia, China and other adversaries fill the vacuum.

So rather than funny ha-ha, the NATO laughter at Trump’s expense should serve as a warning: America’s withdrawal from global leadership under this president is already endangering US security. It will cost the country dearly should he be reelected to another four year term.