Will the US Invade Canada? Mark Carney Reveals He's Considered the Possibility as Relations With Trump Deteriorate

Canadian Prime Minister Mark Carney has confirmed that his government considered the remote possibility of US military action against Canada, describing it as an 'extreme tail risk'.

He said leaders must consider serious but unlikely threats, but declined to say whether specific preparations had been made. 'That's just risk management. That's not a base case, but it would be irresponsible not to' consider the possibility, he told The New York Times.

His comments come as President Donald Trump's tariffs and repeated calls for Canada to become the 51st US state strain ties between the neighbours. While there is no public evidence of an imminent invasion, Ottawa faces pressure to reduce its vulnerabilities without weakening its longstanding defence partnership with Washington.

Why Canada Is Reconsidering Its Dependence on Washington

Carney's comments reflect a broader shift in Canada's approach to its relationship with the US. Ottawa has been seeking greater economic resilience and reviewing its dependence on American technology and defence equipment. Canada's planned purchase of F-35 fighter jets has been under political review, while Carney has discussed reducing reliance on Starlink satellite communications.

Both issues highlight a difficult strategic calculation: equipment and services supplied by the US can provide valuable capabilities, but dependence on a foreign supplier can become a vulnerability when political relations deteriorate. Trade has added to the uncertainty. In July, Carney criticised Washington's intention to impose a new 50% tariff on a significant number of Canadian goods. The Canadian government argued that the measures threatened businesses and workers on both sides of the border.

In an August address, Carney said Canada needed to diversify its trading relationships and build greater strength at home rather than assume its previous relationship with Washington would return unchanged. These economic disputes do not establish that military action is being planned. They help explain why Canadian officials are reassessing the risks of relying so heavily on their closest ally.

Canada's Military Faces a Significant Imbalance

The military gap between the two countries would make a conventional conflict extraordinarily difficult for Canada. The US has a substantially larger armed force and greater military resources. Figures cited in the BBC's reporting put its combined active-duty and reserve personnel at more than two million, compared with fewer than 200,000 in Canada. The US also has a much larger submarine fleet.

A hypothetical Canadian military model reported earlier this year suggested that key strategic positions could be overwhelmed within a week in the event of an American attack. This is a theoretical scenario, not a prediction of what would happen.

Canada has nevertheless been expanding its military capacity. In April, the Department of National Defence announced that the Canadian Armed Forces had enrolled 7,310 Regular Force members during the 2025-26 financial year, exceeding its target of 6,957. The recruitment figures demonstrate an effort to strengthen the armed forces, but they do not establish that the increase was driven by fears of an American invasion.

The Defence Partnership That Would Be at Risk

Canada and the US remain deeply integrated through the North American Aerospace Defense Command (NORAD), a joint organisation established in 1958 to monitor and defend North American airspace and provide maritime warning. The partnership involves shared surveillance, operational coordination, and military training. Canadian and American personnel routinely work together to identify and respond to potential threats.

A military confrontation would place that longstanding cooperation under extraordinary strain. It would also raise serious diplomatic and legal questions about the future of continental defence and the wider alliance system. Canadian Defence Minister David McGuinty has played down the significance of Carney's remarks, noting that militaries routinely assess different risks.

His response reinforces the distinction between considering a contingency and expecting it to happen. The White House has also defended Trump's approach to Canada, saying the president has acted to protect American interests while supporting the Canadian people.

Carney and Trump Continue to Communicate

Despite the tensions, diplomatic contact between the leaders continues. An official readout from Carney's office confirmed that he spoke with Trump on 11 October. Their discussion included the proposed energy ceasefire between Russia and Ukraine, support for Ukraine, and Canadian oil and diesel exports to the US.

The conversation illustrates the complexity of the relationship. Political and economic disagreements have intensified, but both governments continue to cooperate on international issues and maintain essential cross-border ties. For now, Carney's remarks establish that his government has considered an extreme security scenario, not that an attack is expected.