Trump also turned his attacks against Vietnam for its tariffs — “Vietnam takes advantage of us even worse than China” — and Japan, also for purportedly taking advantage of the United States through its defense treaty: “If Japan is attacked, we will fight World War III. We will go in and we will protect them and we will fight with our lives and with our treasure. We will fight at all costs, right? But if we’re attacked, Japan doesn’t have to help us at all. They can watch it on a Sony television.”

Just hours before leaving on the trip Wednesday, for example, Trump angrily attacked a number of those allies in an interview with Fox Business. “European nations were set up in order to take advantage of the United States,” he claimed.

“He’s taken his usual tactic, which is aggravate everyone in advance, up the ante, be obnoxious, with the hope of then acting like the non-abusive parent in the face-to-face meeting,” said Wendy Sherman, the former State Department official who led the U.S. negotiating team for the Iran agreement that Trump scrapped. “What that gets him is not really clear at this point.”

Foreign policy experts outside the administration wonder exactly how that might work, given Trump’s record of lashing out at them with falsehoods and reneging on agreements made under previous administrations — including the original Iran nuclear deal itself.

Trump prepares to meet Thursday and Friday with leaders of the world’s largest industrial economies at the G-20 summit in Japan with the idea, according to the White House, of gaining their cooperation in lowering tensions with Iran. “This is a chance for the president to engage with a number of different international leaders, among our closest partners and allies, to obtain their support and to have discussions about how we can encourage Iran to enter into negotiations,” a senior administration official said this week on condition of anonymity.

WASHINGTON — Having estranged allies with threats and false accusations, President Donald Trump now faces dealing with the latest crisis he has generated, Iran , without any allies at all.

None of Trump’s accusations appears grounded in facts or history. Most European nations have been around for centuries longer than the United States. Vietnam is a signatory to the Trans Pacific Partnership trade agreement, which would have reduced its tariffs on U.S. imports to zero on most products had Trump not withdrawn from it. And Japan’s military is structured the way it is because of U.S. insistence after World War II.

“It makes things very difficult,” said one Western European diplomat on condition of anonymity about Trump’s continual lies. “We all know that it is not true.”

The White House did not respond to queries about the foreign relations consequences of Trump’s near-daily falsehoods. Trump himself, in a recent interview, claimed, falsely, that he was truthful. “I like the truth. I’m actually a very honest guy,” he told ABC News in a recent interview.

And while the segment of the U.S. population that still strongly supports Trump may not care about this behavior, the rest of the world does, critics from both Democratic and Republican administrations said.

“President Trump is viewed as an unsteady and unreliable leader by our closest democratic friends,” said Nicolas Burns, a top State Department official under presidents Bill Clinton and George W. Bush. “The West badly needs a leader to stand up to the two authoritarian powers, Russia and China. But unlike JFK, Reagan and all our postwar presidents, Trump is not leading with sophistication and strength.”

Another Crisis Of His Own Making

While Trump’s handling of trade relationships, particularly his ongoing trade war with China, have created problems for the United States, none presents a crisis as pressing as the near skirmishes with Iran.

Trump initiated the conflict last year, when he withdrew from the 2015 agreement with Iran, Russia, China and the European Union that lifted some economic sanctions on Iran in return for its promise not to pursue nuclear weapons for at least 15 years. The agreement included a regime of inspections to ensure that Iran was complying.

But Trump, as he has done for most things accomplished by or under former President Barack Obama, attacked it during his campaign and has continued disparaging it as president as “the disastrous Iran nuclear deal,” a phrase he used again at a speech to evangelical Christian supporters Wednesday.

The other signatories to the pact all urged Trump not to abandon it, but Trump ignored them.

In recent weeks, Iran has started responding to increased U.S. sanctions more militantly. It is generally believed to have sponsored attacks on oil tankers in the Persian Gulf and last week shot down a U.S. Navy drone over the critical Strait of Hormuz entrance to the gulf. Iran claimed the unmanned craft was in its airspace, while the United States said it was over international waters.

Trump approved a plan for the U.S. military to hit Iranian radar installations and other targets, but then canceled them. He claimed he did so because he learned at the last minute that the strikes would kill as many as 150 Iranians — even though under standard National Security Council procedure, he would have learned that estimate very early in the planning.

Through much of the latest flare-up, Trump has been insisting that all he really wants is for Iran to give up its nuclear weapons program. “We’re not going to have Iran have a nuclear weapon ... when they agree to that, they’re going to have a wealthy country,” Trump told reporters Saturday at the White House.

But that claim raises the question of why he abandoned the existing agreement in the first place, when Iran promised to do precisely that for at least 15 years.

“He can’t show a foreign policy accomplishment,” Sherman said. “His approach to national security and foreign policy hasn’t worked. Trump has tried a ‘fire and fury’ approach to North Korea, Venezuela and now Iran, without anything to show for it ... On Iran he’s been all over the place but has headed us to a disastrous war.”

Adding to the difficulties, she said, is Trump’s tendency to swing from position to position, often undercutting his own administration’s work. Trump went from threatening “fire and fury” on North Korea to praising its dictator within weeks. He threatened to shut the border with Mexico, then reversed. He threatened tariffs on Mexico, then reversed on that, too.

“Everybody knows that the rug can be pulled out from under them. That the president can switch gears,” Sherman said. “With this president, it’s a regular course of business.”

An Easy Fix: Just Rename It The Trump Iran Deal

But just as Trump’s lack of interest in details and need to denigrate Obama has created this crisis, so might his simultaneous penchant for boasting of his supposed accomplishments offer a path to a solution, some of his critics believe.

Trump campaigned on the claim that the North American Free Trade Agreement was unfair to the United States and promised to withdraw from it — notwithstanding legal questions regarding his ability to do so unilaterally. Yet following some minor modifications and the addition of provisions that had been in TPP, which was also disparaged by Trump, he now calls the modified agreement a great success.

With the trade agreement with South Korea, Trump similarly calls the minor changes his administration negotiated a major accomplishment, and now praises the trade deal he once criticized as unfair to the United States.

The “re-branding” of those trade agreements offers the perfect model for getting out of the Iran crisis, said former U.S. diplomat Brett Bruen, who served as director of global engagement in the Obama White House.

“You tweak a couple of points in the deal, and even pay lip service to some of the things Trump’s complaining about like ballistic missiles, and everyone can re-sign the deal and move forward,” he said. “Fundamentally it’s about giving something to Trump to campaign on. If that’s the cost of peace, maybe it’s something they should be willing to consider.”

Such a plan would likely win the support of other nations, the Western European diplomat said, because they do not want to see Iran back out of the agreement and start stockpiling uranium.

“We were very upset when the Americans pulled out of the agreement. Now the Iranians are talking about it, too,” the official said. “Of course, if a similar agreement can be reached and Iran can be brought on board, we would not object to it.”