Open this photo in gallery:

President Donald Trump tours “Alligator Alcatraz,” a new migrant detention facility in Ochopee, Florida.Evan Vucci/The Associated Press

The first bus arrived on Aug. 5, 2022. Greg Abbott, the Republican Governor of Texas, had decided to start shipping migrants to Democratic cities, and that day, deeply blue New York received its first arrivals. It began as a publicity stunt and a way of “owning the libs” during a surge in border crossing under the Biden administration, but the politics of it worked so well, at least from the perspective of Mr. Abbott and the GOP, that he kept it up.

A little over a year later, his office proudly issued a press release: “Texas Transports Over 100,000 Migrants To Sanctuary Cities.” As part of “Operation Lone Star,” the state said it had bused more than 12,500 people to Washington, 37,100 to New York and 30,800 to Chicago.

I keep waiting for some fiendish genius in President Donald Trump’s administration to resurrect the idea. Resurrect it, and direct it at Canada.

Standing in the way, for now, is the Safe Third Country Agreement between our two countries. The STCA says that someone in the United States who crosses the border to make a refugee claim in Canada will be returned to the U.S. to have the matter decided there, with the same rule applying in the other direction. The agreement once had a big loophole, which created the irregular border crossing at Roxham Road, but in 2023 the Biden administration did us a favour and closed it, and Roxham Road.

So, we have an ironclad border agreement. As ironclad as, say, the United States-Mexico-Canada Agreement.

Mr. Trump has made it clear – has he ever – that he wants millions of non-citizens to leave. Some are people illegally in the country; the U.S. is believed to have around 11 million unauthorized residents. The U.S. also has several million lawful temporary residents, including those asylum-seekers who crossed the U.S.-Mexico border in unprecedented numbers between 2021 and 2024. In addition, there are people whose home countries are in such a bad state that then-president Joe Biden and his predecessors offered them temporary protected status. Among them are more than half a million Haitians, whose temporary status the Trump administration is trying to permanently revoke.

Deporting all these people is probably impossible, which may be why Immigration and Customs Enforcement, or ICE, is engaging in highly publicized raids whose main goal may be sowing fear. If targeted groups are fearful enough, some may choose to leave the U.S. voluntarily. The administration has also sent some migrants to nightmarish detention facilities – the CECOT megaprison in El Salvador or the new makeshift centre in a Florida swamp known as “Alligator Alcatraz.” It has publicized how awful these places are, partly to please MAGA voters, but likely also to encourage people to avoid this fate by self-deporting.

U.S. detainees describe worm-filled food, inhuman treatment at ‘Alligator Alcatraz’ migrant centre

Which brings us back to Canada. Over the last two weeks at the main border crossing south of Montreal, more than 1,500 people drove up and asked the Canada Border Services Agency for asylum. Under the STCA, most of those people will likely be quickly returned to the U.S. There are some narrow exemptions, but beyond them, the STCA is clear. It is designed to stop people coming from the U.S. to make an asylum claim.

The foundation for the STCA is that the U.S. is a “safe” country for refugee claimants. It’s a rule-of-law country, just like Canada, that treats refugee claimants humanely and according to the rule of law, just like Canada. The Supreme Court of Canada upheld the STCA on that basis.

But things can change. Look who’s in the White House. Look what he’s doing.

A court challenge arguing that the STCA should be struck down because the U.S. is no longer safe might succeed some day, but not soon. It would take years to work its way through the courts, by which time who knows who will be in the White House, or what U.S. immigration policy will be.

Judge halts deportation of non-binary American in ruling after Trump’s gender edicts

But Mr. Trump has the power to rip up the agreement right now, or ignore it, if he wants to. So far, we’ve seen no evidence of any intent to do that. Nor have we seen signs of wanting to load up buses bound for the Canadian border. The administration is offering people $1,000 to self-deport, but it’s not sending them anywhere in particular.

By 2024, Texas had spent US$148-million busing migrants to blue states. That sounds like a lot of money, until you notice that in the new U.S. budget, there’s US$165-billion for immigration enforcement, including US$75-billion for ICE.

The Trump administration is putting in place the conditions for a massive forced displacement of people. And we’re the next-door neighbours.