WASHINGTON ― Donald Trump is the best at making deals. The best! He’ll tell you himself by tweeting unsolicited advice on how to win in a negotiation or bragging about his book The Art of the Deal (which he didn’t actually write, but whatever).

Now we can see for ourselves how the president puts his deal-making skills to work. Last week, The Washington Post released transcripts of two phone calls Trump had with foreign leaders in January — one with Mexican President Enrique Peña Nieto and another with Australian Prime Minister Malcolm Turnbull. It’s a rare window into how Trump works his magic with people one-on-one when he doesn’t think anyone is watching.

There were no deals made on either call. Trump threatened Peña Nieto, a top U.S. ally, with tariffs on Mexican goods and then warned he’d never meet with him unless he stopped saying publicly that Mexico won’t pay for Trump’s promised border wall. In a heated exchange with Turnbull, also a key U.S. ally, Trump vented about the “stupid deal” the United States had made with Australia to accept refugees into the country. He all but hung up on Turnbull in the end.

Is this as bananas as it sounds? Or maybe Trump is deploying clever, art-of-the-deal tactics that casual observers might miss?

We asked experts in business and diplomatic negotiation to weigh in.

“His skills are few,” John Oesch, an associate professor at the Rotman School of Management at the University of Toronto, said in an email. “He has relied on power (or perceived power), threats, and treating people very poorly to get what he wants. Most negotiation scholars agree that power is an unsustainable way to resolve conflict and a poor negotiating technique, unless you want only to take from the other party and not create any value for either side.”

Anthony Wanis-St. John, an associate professor at the School of International Service at American University, said Trump’s approach was “very transactional,” a style that may have served him well in commercial real estate but will flop in international relations.

“He’s treating Peña Nieto as if he were a merchant and he were a souvenir purchaser haggling for a price,” said Wanis-St. John. “This is ill-suited for complex policy decisions that require much more persuasion and problem solving. It makes Trump look a little venal, a little weak. Not like the president of a great power.”

Carlos Barria / Reuters This isn't an uncomfortable looking picture of Presidents Donald Trump and Enrique Pena Nieto.

But some saw a deeper level of negotiation taking place, even in a constructive way. Daniel Shapiro, an associate professor of psychology at Harvard Medical School and director of the Harvard International Negotiation Program, said if you look past each leader’s stated position and consider his underlying interests, there’s a lot of overlap.

With the border wall, for example, Trump and Peña Nieto disagreed on everything about it, but both worried about losing credibility if they budged in their positions. As for accepting refugees from Australia, Trump worried about looking foolish for taking them in after imposing his travel ban, and Turnbull didn’t want to be strong-armed into breaking a U.S.-Australia agreement. The common denominator, says Shapiro, is saving face.

“Nobody wants to feel taken. Effective negotiators recognize that once we understand each other’s underlying interests, we can truly invent options for mutual gain,” said Shapiro, who wrote the book Negotiating the Nonnegotiable: How to Resolve Your Most Emotionally Charged Conflicts. “These leaders behind closed doors need to feel comfortable sharing information with one another so they can start figuring out options that address each of their constituency’s interests.”

There’s no question, though, that Trump’s default is bullying people to get his way. One of the first stories he tells in The Art of the Deal is about a call he made to a bank executive to try to help an older woman, Mrs. Hill, whose farm was facing foreclosure. Her husband had killed himself in the hopes his life insurance would save the farm, but it turned out it wasn’t enough. The bank executive told Trump the bank was moving ahead with auctioning off the farm, and there was nothing he could do about it.

“That really got me going,” Trump writes. “I said to the guy, ‘You listen to me. If you do foreclose, I’ll personally bring a lawsuit for murder against you and your bank, on the grounds that you harassed Mrs. Hill’s husband to death.’ All of a sudden the bank officer sounded very nervous and said he’d get right back to me. Sometimes it pays to be a little wild.”

His belligerent approach to negotiating is an example of what experts call distributive bargaining — making outrageous demands and hoping the other side gives ground in a zero-sum situation, says Fen Osler Hampson, a distinguished fellow at the Centre for International Governance Innovation in Canada. The problem with applying this tactic to something like, say, threatening tariffs on Mexican imports is that it would damage the U.S. economy, too, by driving up prices of products.

“As we’ve heard from American companies who do business across the border, it’s going to hurt U.S. jobs. You don’t negotiate by shooting yourself in your own foot,” said Hampson. “It’s a pretty weak weapon. Choose your weapons carefully.”

He’s treating Peña Nieto as if he were a merchant and he were a souvenir purchaser haggling for a price. ... It makes Trump look a little venal, a little weak. Anthony Wanis-St. John, associate professor at American University

For those with firsthand experience in international diplomacy, a stunning detail from the president’s calls was that his team didn’t appear to bring him up to speed on the issues relevant to the world leaders he was talking to. For example, Trump told Peña Nieto that he could help him fight organized crime by sending the U.S. military into Mexico.

“Anyone who knows anything about the U.S.-Mexico relationship knows that the idea of U.S. troops on Mexican soil is a no-no,” said Arturo Sarukhán, who served as the Mexican ambassador to the U.S. from 2007 to 2013. “So no one briefed the president and said, ‘This is the type of stuff you can say, this is no-go territory?’ That’s troubling.”

Asked how he would respond to Trump’s push for a border wall if he were still the Mexican ambassador, Sarukhán said he would never challenge how the United States wants to handle its security matters. But he would make it clear to the Trump administration that a wall would tank relations with Mexico.

“All the issues in Trump’s campaign ― the qualifications of Mexicans as rapists and ‘bad hombres’ and the wall ― have poisoned the well of public perception of the U.S. in Mexico,” he said. “This is where I think Trump has had a more detrimental effect on the U.S.-Mexico relationship. He has turned the clock back on how citizens on both sides need to understand they are co-stakeholders.”

Besides, have walls ever really been effective? Even the former Mexican ambassador knows the White Walkers will eventually clear that 700-foot wall of icy magic in “Game of Thrones” and try to wipe out the human race.

“Oh, they’re going to get past it. We can see that coming,” Sarukhán predicted. “I’d love to see Daenerys and Jon Snow slugging it out with dragons and dragon glass.”