As I write, the prime minister of Canada, Justin Trudeau, is hanging on by a thread following the resignation of his finance minister, Chrystia Freeland.

The problem? Trump’s threat of a 25% tariff on Canadian goods. Never mind that such a policy may be struck down by the courts as incompatible with the United States-Mexico-Canada Agreement rules that Trump himself boasts of having established.

Never mind, either, that tariffs will inflict more pain on the U.S. than on Canada. Yes, there will be a cost to Canadian exporters, but it will be outweighed by the cost to American consumers who, as prices rise, will have less to spend on everything else, so hurting the entire American economy.

And never mind the bizarre justification for the levy, namely the fentanyl crisis, which, by the way, seems at last to have peaked. This is, I think, the first time that tariffs have been expressly proposed as a way of trying to make other countries responsible for solving a domestic U.S. problem.

None of those things matters either to Trump himself or to his voters. All they see is that Trump may have toppled the leader of a G7 nation with a single post on Truth Social. Trump’s readiness to determine his international policy around which foreign leaders kiss up to him personally, an attitude that previous generations would have seen as un-American, is now saluted as a sign of strength.

With Canada’s prettyboy PM, it was always personal. Trump resented Trudeau’s earlier criticism of him when he took office in 2017, and relations with Canada never properly recovered. The incoming president has plainly not forgotten his grudge. Hence the inclusion of Canada among the three countries that he has singled out for trade sanctions.

Although threatening tariffs is always a bad idea, I can just about understand the logic of saying that Mexico can avoid them by doing more to control its side of the border. I can even see, though it is more of a stretch, how China could crack down harder on drug traffickers. But Canada? What is the Big Dominion supposed to do to?

Canada’s provincial governments held an emergency summit in Toronto on Monday to discuss how to respond while the federal government flailed around. “It’s chaos right now up in Ottawa,” said Doug Ford, the man-of-the-people Premier of Ontario.

Trudeau, determined to avoid his mistake of 2016, flew to Mar-a-Lago to make peace, exactly the kind of thing that Trumpies like to see: a client foreign leader coming to do homage at court. But his submissiveness did not play well at home. Hence the current crisis.

I don’t want to overstate things. Trudeau was already unpopular. Trump’s intervention simply brought to a head the discontent of his Liberal MPs, who can see him leading them to electoral disaster.

What we are watching is a textbook example of how Trump likes to do business. Issue a blood-curdling threat, stand back, and let the cards fall where they may.

In a similar vein, the incoming president has threatened Hamas with “ALL HELL TO PAY.” What is that supposed to mean? “Well,” he elaborated, “they’re going to have to determine what that means, but it means it won’t be pleasant. It’s not going to be pleasant.”

Is this an empty threat, recalling King Lear: “I shall do such things — what they are yet I know not — but they shall be the terrors of the Earth”? Or does he have something specific in mind? Will Hamas wait to find out? Will the Canadians? Will the Mexicans, the Ukrainians, the Russians, or the Chinese?

As Rich Lowry puts it, the closest thing to a Trump Doctrine is: “Find out if I’m serious or not at your own risk.”

Now, you might see this as a welcome reassertion of American muscularity, a throwback to the swashbuckling style of Teddy Roosevelt. Or you might see it as an alarming retreat into personal government, where the national interest is subordinated to the whims of one boss.

Most voters seem to like it. Unusually, Trump’s approval ratings have climbed between the election and the inauguration. In a tribal species, there will always be a market for assertive alpha males, for the kind of strongman government that has been perennially popular in less advanced nations. Either way, the ideal on which the U.S. was founded, John Adams’s vision of “a government of laws not of men,” seems further away than ever.