President Donald Trump. Associated Press/Evan Vucci Last week, President Donald Trump gave a disastrous interview to The Economist. Flanked by his aides, the president was rambling, uninformed, confused, and dishonest — and never corrected by those supposed to balance a man who was meant to disrupt, but not dismantle, US politics.

Afterward, David Rennie, the journalist who conducted the interview, was himself interviewed by Public Radio International, and he made one crucial point that anyone concerned about Trump's economic policy should understand.

From the interview (emphasis added):

"A lot of the reporting has said that there's kind of two completely different factions [in the White House]. One is kind of moderate, globalist view led by his son-in-law, Jared Kushner, and then the other this kind of very dark, nationalist, angry view, and that somehow those two factions are locked in a fight that one of them might win, and then that somehow will set the policy.

"Having spent that much time in the West Wing and doing this interview, I would say we came away with a different impression, which is that, fundamentally, Donald Trump is a nationalist — he's a kind of nationalist with a grievance. He thinks that the world has taken advantage of America for too long, it's time for America to be tougher and gruffer and more assertive and more selfish.

"So if there are different voices — and there are — it's more a question of tactics. It's kind of, how do you cut that best deal? Do you bang your fist on the table, or do you offer concessions? So I don't think there's a kind of chance that a globalist, moderate wing is somehow going to win the argument and change Donald Trump. He is who he is."

During the campaign, a lot of Trump's supporters touted his practicality, saying he had no ideological allegiance to either party and, as such, could look beyond politics to find a better, more practical solution.

According to Rennie, that's simply not so. Trump may not be practicing the politics of a Democrat or Republican, but that of protectionism, victimization, aggression, and nationalism — a particularly heady form of entitlement. These are incredibly dangerous forces in the global economy when any country tries to harness them, and even more so when that country is the richest and most powerful, hardly a victim.

So this is what we have. Trump is the bully who was picked last in gym class in the fourth grade and still seethes about it in his junior year of college. Even as an adult, he can't help himself anytime he sees a kickball.

Reciprocity is not a thing, guys

Trump was about to leave NAFTA until some "fairly startling" (Rennie's words) moves by his Cabinet, the leaders of Mexico and Canada, and corporate executives stopped him.

But we won't always be so lucky. And we are about to test that luck repeatedly.

Trump's team is touting a made-up trade term: reciprocity. Most basically, it means putting pressure on countries to lower their tariffs or change their economic structures to something more palatable for the Trump administration. If that sounds heavy-handed, it's because it is.

What's most worrying about that is not what the administration may get done, but what it might accidentally do in the process. Rennie's point about tactics is crucial. There may very likely be unintended consequences in aggressively confronting countries to make them bend to the US's economic will.

Take, for example, the 20% tariff Trump placed on Canadian softwood lumber, a fight that previous administrations lost time and time again. Paul Frazer, a former Canadian ambassador, told Business Insider that restarting it was emotional — and a point of pride — for Canadians.

"It's the oldest chestnut and the nastiest one from the Canadian perspective," he said. "For the Canadians, it's more than an economic issue, it's wrapped up in what is fair and what is right and wrong."

So Canadians are starting to feel negatively about their neighbors to the south.

"The trade matters such as softwood contributes and will continue to contribute to that opinion," Frazer said.

Trump should not be allowed to carelessly and unnecessarily fray relationships across the globe. Think about what that would mean if something dangerous were to happen in the world and the US had squandered its goodwill chasing nonsense grievances in the paranoid mind of an ignorant ideologue.

The longer this goes on, the more vulnerable we all become.