Canadian Prime Minister Mark Carney told The New York Times he has examined the possibility of a US military attack on Canada, describing it as an "extreme tail risk" — low probability, catastrophic consequence. "That's just risk management," said the former Bank of England governor. "It would be irresponsible not to." Experts uniformly call an actual attack "somewhat unthinkable," but the fact that a sitting PM is publicly war-gaming the scenario marks a structural shift in how Ottawa perceives its southern neighbour. The backdrop is an escalating trade war that has moved well past posturing. Trump imposed 25 percent tariffs on Canadian goods in early 2025, ostensibly over fentanyl flows. Trade talks collapsed in August. Both sides have since escalated to 50 percent tariffs on $20 billion of each other's goods. Canada's exposure is severe: 72 percent of its $556 billion in goods exports — roughly $400 billion — flow to the US. Trump has repeatedly called Canada a potential "51st state" and provocatively renamed Lake Ontario "Lake America." Carney's response has been to systematically reduce dependence. Canada is reviewing its planned purchase of American F-35 fighter jets and intends to wean itself off SpaceX's Starlink satellite internet service. The EU has offered Canada associate membership. Canada has applied to join the UK-led Joint Expeditionary Force, a European military coalition. These are not symbolic gestures — they are the architectural moves of a middle power rerouting its security and economic plumbing away from a single patron. The military asymmetry is total on paper. The US defence budget dwarfs Canada's by roughly 20-to-1. But as Ty Solomon, a professor of international relations at the University of Glasgow, noted, the prolonged US war against Iran has "cast doubt on assumptions about overwhelming US military force and effectiveness." Eric Taylor Woods of the University of Leeds added that Canadians would not "simply accept the loss of their sovereignty" despite the capability gap. A US attack, Solomon argued, would be "an unmitigated disaster for American global interests" — evaporating remaining allied trust and accelerating the formation of non-American security blocs. The deeper geopolitical context extends beyond bilateral friction. Russian and Chinese activity in the Arctic, US threats to annex Greenland, and what Solomon called a "multifaceted geopolitical environment" mean that escalation in one theatre could trigger unexpected dynamics in others. Carney framed this reality at the World Economic Forum in January: "If we're not at the table, we're on the menu." Despite the posturing, channels remain open. Carney told the Times he and Trump speak "frequently" and described the relationship as "direct." Woods observed that Trump has so far avoided the personal insults he routinely directed at Justin Trudeau. But Solomon cautioned that privately, Carney's team likely trusts the Trump administration very little: "Every agreement is built upon uncertain foundations" when US foreign policy shifts "seemingly on a whim." What matters structurally is not whether a US-Canada war happens — it almost certainly won't. What matters is that Canada's political class now treats its entire economic and security architecture as a single point of failure, and is acting accordingly. The question is whether diversification can happen fast enough to change Canada's negotiating position before Trump extracts the concessions he wants.
