Canada’s contingency planning for American military action says less about Washington’s intentions than about how much Canada’s certainties have eroded, and about what Ottawa should do next.
When the New York Times asked Prime Minister Mark Carney whether he took Donald Trump’s 51st-state threats seriously, he paused before answering. He said leaders have a responsibility “to look at extreme tail risk,” calling it “just risk management” and “not a base case,” but said it would be irresponsible not to prepare. The wording matters. According to the Times’s Canada bureau chief, Carney “did not use the word ‘invasion'”; that was the newspaper’s word. Carney was talking about risk management. The coverage turned it into a war plan.
He was still right to do it. The more useful question is what this kind of planning is for.
Why this is no longer a thought experiment
Two years ago, a Canadian prime minister studying American military action would have sounded unhinged. Consider what has happened since. On January 3, 2026, the United States launched a large-scale military operation against Venezuela, capturing President Nicolás Maduro and his wife and taking them to New York. In the same month, over Greenland, the White House said that “utilizing the U.S. military is always an option” for gaining control of territory belonging to a NATO ally. European NATO states including France, Germany and Sweden sent personnel to Greenland on January 15 for exercises meant to show they were ready to defend it. That crisis only ended last week, when Trump announced a deal to expand the U.S. military presence in Greenland while leaving the territory in Danish hands.
Canada’s own situation has worsened too. The trade war has escalated since efforts to reach a trade deal collapsed in mid-August. Trump told journalists in 2025 he would use “economic force” to push Canada into union with the U.S., and he routinely calls Carney “governor.” In May 2025, Trump did say military action was “highly unlikely” and that he couldn’t see it happening with Canada. But he said similar things about allies and then threatened them anyway.
So the probability is very low, and it is not zero. The damage if it happened would be enormous. That combination is what contingency planning exists for.
What the military actually modelled
The details reported so far are sobering. In January, the Globe and Mail reported that planners modelled an invasion from the south and expected American forces to overcome Canada’s strategic positions on land and at sea within a week, possibly within two days. Because Canada lacks the troops and equipment for a conventional defence, the military envisions unconventional warfare: small groups of irregular military or armed civilians using ambushes, sabotage, drones and hit-and-run tactics. The model also assumes warning signs: the military expects clear indicators before any invasion, including a U.S. decision to end bilateral NORAD co-operation, and Canada would likely call on Britain and France for help.
It is important to be clear about what this is. A military model is a conceptual and theoretical framework, not a plan, which is an actionable, step-by-step directive for executing operations. Nothing is being mobilized. Officers are thinking through a scenario.
Canada has done this before
The historical parallel is well known. In 1921, Lt.-Col. James “Buster” Sutherland Brown drafted Defence Scheme No. 1, a plan for a surprise Canadian invasion of the northern United States once there was evidence of an American attack. The idea was to buy time: when resistance grew, Canadian troops would retreat and destroy bridges and railways to slow the pursuit. Washington had its own version. War Plan Red envisioned attacks on Halifax, Quebec City, Montreal, Toronto, Winnipeg, Vancouver and Victoria, and was kept current until the late 1930s, when new plans had the two countries cooperating against common enemies.
Pierre Berton later dismissed Brown’s scheme as “madcap.” The mockery misses the point. Neither country wanted war, and neither plan was ever used. Both governments thought through a worst case and then, as their alliances changed, shelved the plans. A contingency plan doesn’t predict a war or cause one. It’s a way of thinking about what could happen.
The serious objection is about disclosure
Critics are not wrong about everything. Former defence minister Peter MacKay argued that Carney’s remarks move Canada “from the realm of retaliation to provocation” and said the priority should be getting back to the bargaining table on tariffs. The White House’s response was predictably defensive. It said Trump has done “more than anyone” to protect Canada and suggested Carney should be grateful.
That objection deserves an answer, because it isn’t really about whether to plan. Almost no serious person argues Canada’s military shouldn’t examine worst cases. As Defence Minister David McGuinty said, “all militaries in the world spend time analyzing risk scenarios.” The real disagreement is about whether to talk about it publicly. There is a real risk in doing so: in the middle of a trade war, public talk about invasion scenarios can harden positions on both sides and give Washington’s hawks a grievance.
The case for disclosure is also strong, though. Some analysts read Carney’s comment as a signal rather than a slip. One argued that it underscores the absurdity of what the American president has said. In effect, it tells Americans how their president’s words sound to their closest ally. As Tom Mulcair put it, the scenario exists because “Donald Trump said he was going to try to make Canada the 51st state,” and not because someone in Ottawa invented it. On balance, the planning was clearly right. Discussing it publicly was a reasonable judgment call, and Carney kept it narrow by declining to give any details.
The real value is in what the exercise shows about dependence
The most important lesson isn’t about tanks at the border. An invasion is the least likely way Canada’s sovereignty could be undermined. The more plausible risks are the things that sit between trade war and armed conflict: pressure applied through infrastructure Canada doesn’t control.
That is where the planning pays off. Carney told the Times that Canada is reducing its reliance on the U.S., including on Starlink, and is reviewing its planned F-35 order. He described the fighter decision as a real choice “because of differing capabilities, because of strategic dependencies, and because of the economic return.” Both questions come from the same exercise. Once you ask what happens if Washington becomes hostile, you have to ask which Canadian satellites, fighter jets, software updates, payment systems and energy links depend on American goodwill. Those vulnerabilities matter whether the danger comes from Washington, Moscow or a ransomware gang.
Aisha Ahmad, a University of Toronto scholar of insurgency, made the deeper point early last year: an invasion would immediately defeat the Canadian Armed Forces, “but a conventional military victory is not the end of this story. It’s just the beginning.” Her conclusion, which is the implicit logic of the military’s model, is that Canada’s deterrence doesn’t rest on winning battles. It rests on being impossible to govern against its will. That depends on social cohesion, resilient institutions and allies who would care, which are the same things that protect a country against almost every other serious threat.
Canada is at least now paying for the basics. NATO data show Canada spent more than $60 billion on defence in 2025, reaching the 2 per cent of GDP target for the first time in more than a decade, and Carney has pledged to reach NATO’s new 5 per cent target by 2035.
What Ottawa should do now
First, keep the operational details classified, but stop treating the principle as embarrassing. Serious states plan for tail risks, and saying so plainly is a sign of seriousness, not hysteria.
Second, broaden the exercise beyond the military. The central question is less “can we fight?” and more “what breaks first?” That means looking at energy grids, telecommunications, satellite access, financial plumbing, food supply chains and critical minerals. That review is where most of the benefit lies.
Third, keep cooperation that works. The military’s own model treats the end of NORAD as a warning sign. That is a good reason to protect NORAD and the practical military relationship even as trade relations sour. Planning for the worst case is compatible with trying to keep things normal.
Finally, keep perspective. Planning is not a prediction. Buster Brown’s scheme ended up in the archives, which is the best outcome for any contingency plan. The goal is not to expect war with the United States. It is to make sure that no one in Washington, or anywhere else, can assume Canada has never thought about it.
