President Donald Trump may be backing down on his threat to seize Greenland, but his push for the island has already changed the way foreign policy is done in Washington and beyond.

More than any other global issue I’ve seen Trump tackle, his obsession with Greenland has shifted paradigms and broken brains. And I’m talking about big brains: diplomats, foreign policy analysts, economic specialists. People on the left and a fair number on the right.

Even diplomats not from Europe are rattled.

“It was like, huh?” said an African official in Washington. “The shocking part was the level of the threat, how serious he was. And it’s not over.”

Suzanne Maloney, a Middle East analyst who directs the Brookings Institution’s foreign policy program, said it has felt “as though the world has gone mad.” She added: “The language, the determination on this particular issue just feels disconnected from our national interest.”

Not long ago, many foreign policy professionals were still asking if the post-World War II “rules-based international order” was dead. In the wake of Trump’s Greenland gambit, I’m hearing more flat-out declare it’s a corpse. Canada’s leader, Mark Carney, said as much at the World Economic Forum this week.

That means foreign policy consultants are rethinking advice they give to clients, while think tankers are reconsidering their travel and study plans. Maloney, for one, said she had to submit her department’s policy research priorities for the coming fiscal year to her superiors this week, but that she warned them the list could change by next week.

Diplomats from Europe said the Greenland crisis has created a new reality because it’s clearer than ever that even allies are not safe from Trump’s machinations.

“It creates a sort of fear in the European Union,” one European diplomat told me. “It’s not just about expanding our imagination, but just to realize this is a different day and the traditional ways — the rules, the laws — don’t necessarily apply. Everything is now negotiable.” (I granted the diplomat and others I spoke to anonymity to discuss a sensitive issue.)

That’s even though Trump toned down his rhetoric Wednesday. He first said he won’t use military force to take over Greenland and later announced he’d withdraw a threat of tariffs after reaching a “framework” deal over the territory. Few details were immediately available.

But Trump, who has wanted Greenland since his first term, changes his mind so often that Europeans — or any other global actor — would be foolish to trust that this issue is resolved. He has a history of walking away from deals, including ones his administration crafted. He also has three more years in this term.

The sense from Trump critics I spoke to for this column was that they’re not ready to relax even though he’s softened his tone.

“His overriding interest is to expand the map of the United States,” said Eric Green, a former senior National Security Council official who dealt with Russia and Central Asia in the Biden administration. “Sooner or later he’s going to come back to that.”

Trump’s Greenland desires have scrambled the plans of many foreign affairs practitioners to a degree that’s unusual even for a president who delights in upending conventional wisdom.

The whole Greenland debacle is especially hard for people who teach international relations, many of whom keep having to redo their syllabi. These scholars are trained to use neutral language to explain the actions of power players. The goal is to help students learn methods to understand the world.

But “there comes a point where you just want to say this is a fucking stupid idea,” said Daniel Drezner, academic dean at Tufts University’s Fletcher School.

Trump’s Greenland push also came with a level of personal self-interest that went beyond the “America First” justification he has used to explain other actions. He has said he is pursuing Greenland in part because he was upset that he had not been given the Nobel Peace Prize.

“It feels a bit like ‘The Twilight Zone’,” Green said. “He’s linking a personal slight to a geopolitical request that is completely unreasonable.”

Trump’s foreign policy moves typically have some logic behind them. You don’t have to agree with the logic, but you can still see it.

He bombed Iran’s nuclear facilities because it was a rare chance to set back a program that could threaten the U.S. He captured Venezuelan leader Nicolas Maduro because he wants access to Venezuelan oil and could make a case that Maduro is a narcotrafficker whose regime undermines the U.S. He imposed tariffs on practically every other country because he believes it will help the U.S. become more economically self-sufficient over time.

In bullying Denmark to hand over, or sell, Greenland, Trump and his aides have said they are thinking of the U.S. national interest. The island is strategically located and contains many useful natural resources.

Alex Gray, who served in a senior role at the National Security Council in Trump’s first term, said one long-term worry is that Greenland’s residents will eventually insist on full independence from Denmark, making them more vulnerable to China or Russia.

“Which is why we need to put our best foot forward and offer them some very compelling things,” Gray said of U.S. overtures to Greenland.

Trump does have a history of making seemingly outrageous demands before settling for whatever he can get. He’s sometimes been spooked by the markets, which have not reacted well to his push for Greenland.

Some people say he chickens out, but the approach has its benefits. It forces people to talk about issues that otherwise get ignored (like the fecklessness of the U.N.) or settle for terms that otherwise they’d abhor.

Still, Trump’s insistence that the U.S. control Greenland has stained America’s reputation with its allies. That’s a price detractors say should never have had to be paid.

After all, Washington already has tremendous access to Greenland under past agreements with Denmark; U.S. troops already operate in Greenland and Washington can send more. Trump’s demand that Denmark grant the territory to the U.S. is a body blow to U.S. relations with its European allies. It also hurts NATO, a military alliance that includes the U.S. and Denmark — and which would defend Greenland should an adversarial power threaten it.

For people trying to advise clients, teach students, make policy or otherwise engage the public, Trump’s Greenland moves underscore how hard the foreign policy prediction game has become.

The true effects of Trump’s moves may not be felt until long after he’s out of office. He often acts as if he’s making a more significant change than he really is; the effective rate of his tariffs, for example, is often lower than his proclamations. Many of Trump’s policies also contradict one another. For instance, Trump supposedly wants African countries to build their economies and be less dependent on foreign aid, but his tariffs hurt those economies.

It doesn’t help that so much of what’s happening with Greenland comes down to the personality of one man.

This is probably an argument for all of us to take a class on political psychology. Or maybe join a support group for exhausted foreign policy professionals?