Canada wargames a highly unlikely US invasion amid tensions under Trump

Canadian Prime Minister Mark Carney said his government had considered a possible US invasion. He stressed that the risk was low but said he had a responsibility to examine every scenario as relations change under President Donald Trump.

Concern has been fuelled by US tariffs and Trump’s repeated calls for Canada to become the 51st state. In 2025, however, the US president described the use of force against Canada as “highly unlikely”.

Allies preparing for conflict

Canada and the US are both members of Nato, conduct joint Arctic operations through NORAD and regularly share intelligence. Retired Canadian air force lieutenant-general Christopher Coates said a potential conflict might begin with cyberoperations rather than an open assault.

A Leger poll in January found that more than 30% of Canadians considered a US invasion likely after Nicolás Maduro was captured in Venezuela. Military experts who spoke to the BBC described the scenario as a long shot.

Canada’s military planning model

A Canadian military model reported by the Globe and Mail earlier this year said US forces could overwhelm Canada’s strategic positions within a week. Canadian troops, quickly outnumbered, would then be expected to turn to guerrilla-style warfare; France and Britain could also be asked to provide support, according to the newspaper.

Coates described the exercise as limited combat planning rather than a full-scale war plan. He said Canada was catching up after lagging behind its Nato allies in preparing for a ground invasion.

Historical fears of US expansion

Canada and the US became close allies after the Second World War, but American forces had previously attacked British North American colonies. The US captured Montreal and nearly took Quebec City in 1775, then invaded Upper Canada, Lower Canada and the Maritime colonies repeatedly during the War of 1812.

Tim Foran, a researcher at the Canadian War Museum, said fear of the US was part of Canada’s political identity. After the First World War, Canada also drafted a war plan that included gathering intelligence on US border cities.

Canada considers stronger defences

Coates said a call by Canada’s defence chief to expand the military, including as many as 300,000 lightly trained citizen soldiers, showed the country was trying to close a preparedness gap amid unpredictable geopolitics.

Matthew Schmidt, a professor at the University of New Haven, said Canada’s preparations reflected a major shift in the international order. He also suggested that, if conflict occurred, the US might focus on Canadian oil and minerals and attempt to remove the political leadership; that remains an assessment of a possible scenario, not a confirmed plan.