What a 'very, very, very unlikely' U.S. invasion of Canada might look like
The Canadian military would be “foolish” not to draw up plans on how to respond to a U.S. invasion, says an expert on Canada-U.S. relations.
The Canadian Armed Forces is reportedly looking at employing insurgency-style tactics like those used in Afghanistan in the unlikely event that the U.S. military attacks Canada.
“They’d be foolish if they didn’t, if only because Donald Trump has said he’s concerned about Greenland. He’s concerned about the threat from Russia and China in the Arctic. Sub out the word Greenland for the word(s) Baffin Island or Iqaluit or any other sort of place north and you’d have a potential for American troops up there,” said Asa McKercher, the Hudson Chair in Canada-U.S. Relations at St. Francis Xavier University’s Brian Mulroney Institute of Government.
Canada’s top soldier, Gen. Jennie Carignan, was out of the country Tuesday and unavailable for comment.
“As is routine, the Department of National Defence and the Canadian Armed Forces conducts analysis on a variety of scenarios, both real and hypothetical, to ensure readiness,” Kened Sadiku, who speaks for DND, said Tuesday in an email. “As a matter of operational security, and as a critical element of our defence, we do not confirm such matters in public.”
While a U.S. invasion of Canada is “very, very, very unlikely,” McKercher said it’s not out of the realm of possibility.
After he was elected in 2024, Trump referred repeatedly to Canada as the 51st state. While his talk of annexation and how it would benefit Canada has dried up in recent months, Trump posted a doctored image overnight on his social media platform of a map showing Canada, Greenland and Venezuela covered in the U.S. flag.
Donald J. Trump Truth Social Post 12:58 AM EST 01.20.26
— Commentary Donald J. Trump Posts From Truth Social (@TrumpDailyPosts) January 20, 2026
President Trump just posted a photo of the Oval Office with him displaying a map that shows Greenland, Venezuela and Canada as part of the United States of America pic.twitter.com/krAMvY65Qa
“Donald Trump is treated in some ways like a toddler,” McKercher said. “He does silly things and people don’t believe him until he follows through.”
A Canadian insurgency would be effective because many Americans wouldn’t want Canada to be invaded, he said.
“This would create big problems potentially within the United States itself,” McKercher said.
Many Canadians would resent an American invasion, “and could make life difficult for Americans,” he said.
“If it came to that, what would prevent Canadian military members or insurgents from going across the border at any of the many, many points along our border that aren’t patrolled, and blowing up bombs in American cities? It’s inconceivable, but a crazy thing that I think clearly is on the mind of very serious people.”
Citing two unnamed senior government officials, The Globe and Mail reported that the model being developed “was a conceptual and theoretical framework, not a military plan, which is an actionable and step‑by‑step directive for executing operations.”
McKercher said it’s “reasonable” to expect that Canada’s military would be unlikely to stave off a U.S. invasion for more than a day or two.
“We have a very small military; they have a very effective military,” McKercher said. “They have the ability to destroy our command-and-control centres, target our logistics networks, they’re aware of where all our bases are. There’s not a lot of hiding that we could do, probably, from American cruise missiles and drones.”
Canada’s former national security and intelligence adviser, Vincent Rigby, said Tuesday that a U.S. invasion “falls into the category of very low probability, but very high impact, to put it mildly.”
Trump “talks a lot of smack,” Rigby said. “It’s part of his playbook. It’s destabilizing.”
But the Canadian military is supposed to plan for all scenarios, said Rigby, a former top intelligence adviser to former prime minister Justin Trudeau who spent 14 years with Canada’s Department of National Defence.
“They’re very good at it and given the current situation in the world, given the current state of Canada-U.S. relations, given the current state of U.S. foreign policy, I’m not completely surprised that they’re looking at possible scenarios.”
He fears the revelation that plans are afoot will agitate apprehensions amongst a lot of Canadians.
“It certainly stirs the pot a little bit,” Rigby said.
A U.S. invasion of Canada would be extremely unpopular amongst Americans, he said.
“That is a country that is completely and utterly divided — polarized,” Rigby said.
“There would be huge, huge segments of the U.S. population that would be just, ‘You’ve got to be kidding. We’re invading Canada?’ Who knows what that might set off in the United States?”
That “might be the last straw for a lot of Americans in terms of this president is completely and utterly off his rocker,” Rigby said.
Just because Trump posted a doctored photo recently of a map showing Canada covered in the U.S. flag doesn’t mean he’s about to launch an invasion, Rigby said.
“I think it’s part of his negotiation tactics. He likes to put governments on their heels. It strengthens his own bargaining position,” he said. “The crazier stuff that he puts out there, it gives him greater leverage. It’s sort of the mad man theory — do crazy stuff and people will give in. People will make concessions.”
Trump appears focused on Greenland right now, Rigby said.
But “he is thinking about the Arctic, writ large. That includes Denmark and Greenland, but it also obviously includes Canada. And so, we have to keep up our guard in the Arctic.”
Rigby fears Trump “could do something silly in the Northwest Passage, or could do something silly on a Canadian island in the Arctic archipelago. So, is he going to seize all of Canada and try to make it the 51st state? Not in the near term. Don’t see that. But could he do something very aggressive in the Arctic if he feels we’re not doing our job? Absolutely. It’s a tightrope that Canada has to constantly walk right now with the United States.”
A U.S. invasion would likely target Ottawa, he said.
“They’d probably go straight for Ottawa and try to cut off the head of the government,” Rigby said.
“But this is a huge country — 10 million square kilometres, second largest country in the world. Vast parts of the country without huge population density. Would they be able to take every single city? Every single province? No.”
The Canadian military likely wouldn’t be able to stop U.S. tanks rolling across the border, Rigby said. “It would probably be a matter of days, if not hours. But could we put up resistance in the rest of country? We probably could — some low-level guerrilla type activity.”
While the U.S. has the strongest military in the world, “even they have limited resources at the end of the day,” Rigby said. “The notion that they’re just going to take a country as large as Canada and control it in the face of guerrilla opposition and that sort of thing – it’s a little bit much. So, it’s a classic case of be careful what you wish for and how much you want to bite off.”
Canada needs to show the U.S. it is serious about defending the Arctic, Rigby said. “All the stuff we say we’re going to do in the Arctic, including purchasing submarines, increasing our satellite capability, our surveillance capability, we’ve got to do that. And we’ve got to do that fast.”
There was no talk about how to thwart a U.S. invasion when Rigby was national security intelligence adviser during the last year of Trump’s first presidency, he said. “And I don’t think it’s been an issue under any government for a long time…. You probably have to go back almost a hundred years since that was last taken seriously.”
Canada has planned for a U.S. invasion before, McKercher said Tuesday.
“Probably the most famous Canadian military plans regarding an American invasion occurred in the 1920s,” he said.
McKercher pointed to Canadian military Lieutenant Colonel James “Buster” Sutherland Brown’s plan formed over a century ago in the event of a war between Britain and the U.S., “which even in the 1920s seemed pretty crazy, but was potentially conceivable.”
Brown’s plan involved Canadian preemptive strikes “to invade American border towns and then wait for the British Empire to sort of come save us,” McKercher said.
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