London ridicules the ridiculous

Will President Trump ever learn — or care — that his fact-free tweets have painful consequences, not just at home but abroad? Surely he must sense this by now, as the administration faces the outrage of British allies who have been dragged into his increasingly bogus allegation that he was spied on by the Obama administration.

In a feverish defense of Mr. Trump’s charge, the White House press spokesman, Sean Spicer, on Thursday cited an unsubstantiated Fox News report that the British intelligence agency, Government Communications Headquarters, had been secretly called on by the Obama administration to spy on Mr. Trump.

British officials were terse in their fury, dismissing the allegation as “nonsense.” “Utterly ridiculous and should be ignored,” the British agency said.

White House aides tried to calm the waters with incensed British officials, who said they had received assurances that the allegations would not be repeated. But no one speaks for Mr. Trump. On Friday, he stuck by his wiretapping charge — without disputing a Fox News commentator’s claim of British spy involvement — despite Republican leaders in Congress debunking his accusation, saying that intelligence investigators have found no evidence to back it.

“Very soon,” Mr. Trump said in an interview on Wednesday night, the administration “will be submitting things” to Congress to prove his outrageous accusation.

What things? From what Alt-Right Tooth Fairy? Surely the nation — even Mr. Trump’s credulous base — is learning to recognize his dodges when he is cornered. “I think you’re going to find some very interesting items coming to the forefront over the next two weeks,” Mr. Trump promised, probably quite aware that he can always generate a different controversy by tweet when nothing he says comes true.

Mr. Trump’s pattern for abusing the truth was established in his disgraceful five-year-long “birther” campaign, in which he promoted the lie that President Obama was not born in the United States. “I have people that have been studying” the issue, he said in an interview in 2011. “They cannot believe what they are finding,” he said, grabbing national attention with a vile slander against the president.

Mr. Trump backed off that fabrication only when the Republican nomination was safely his. He briefly stipulated the obvious, that Mr. Obama was born in the United States. But he instantly concocted a new falsehood, insisting that his opponent Hillary Clinton, not he, initiated the birther conspiracy.

He never publicly apologized to Mr. Obama for that slur (or to Mrs. Clinton, for that matter). Nor is he likely to apologize to Mr. Obama or Downing Street for the latest. “If he didn’t do it, we shouldn’t be reckless in accusations that he did,” Representative Tom Cole, Republican of Oklahoma, said Friday of Mr. Obama, in finding Mr. Trump offered no “compelling truth.”

The idea of Mr. Trump apologizing for anything is surreal. At a news conference on Friday with German chancellor Angela Merkel, Mr. Trump said he “very seldom” regrets his tweets. He tried to argue that the White House was silent about the unsubstantiated story of British espionage, though he did take care to praise the claim as coming from “a very talented” commentator. (Meanwhile, of course, he continues to show a mysterious lack of concern for what American intelligence has found to be actual foreign meddling in American politics, by Russia.)

Of course, it was Mr. Spicer, the president’s spokesman, who had dutifully come forth, more as minister of propaganda to compound the smear by stretching it all the way to London.

“I don’t think we regret anything,” Mr. Spicer blithely told reporters on Friday, even after Fox News said it “knows of no evidence” that the London spying tale is true.

A version of this editorial appears in print on March 18, 2017, on Page A18 of the New York edition with the headline: London Ridicules the Ridiculous.