The United States has suspended its participation in a key joint continental defence body with Canada, marking a fresh strain in relations between the two long-standing allies.
US Undersecretary of Defense Elbridge Colby announced that Washington will no longer take part in the Permanent Joint Board on Defense, a forum established during World War II to coordinate North American security between the two countries. He said the decision is part of a broader review aimed at reassessing the value of the arrangement, while also accusing Canada of not meeting its defence commitments.
Colby argued that Canada must prioritise “hard power” and increase its military capability, saying there is a growing gap between rhetoric and actual defence investment.
The move comes amid rising tensions between Washington and Ottawa since the return of US President Donald Trump to office in 2025. His administration has repeatedly criticised NATO allies, including Canada, for relying too heavily on US military support while allegedly underinvesting in their own defence systems.
The Permanent Joint Board on Defense, created during World War II, has historically served as a cornerstone of US–Canada military cooperation, focusing on continental air defence, intelligence sharing, and strategic planning.
However, relations between the two countries have deteriorated in recent months, extending beyond security concerns into trade and diplomacy. The US has imposed tariffs on Canadian imports and raised concerns over border security, including illegal migration and drug trafficking—claims Canadian officials have disputed or described as exaggerated.
Canada, under Prime Minister Mark Carney, has pledged to boost defence spending significantly, with plans to allocate a higher share of GDP toward military and security-related infrastructure. Ottawa has also signalled a long-term strategy to reduce dependence on the United States by strengthening partnerships with other global “middle powers.”
The decision has sparked criticism from some US lawmakers, who warn it could damage one of the world’s most stable security partnerships. Republican Congressman Don Bacon said diplomatic tensions and political rhetoric, including past remarks suggesting Canada could become the “51st state,” have undermined trust between the neighbours.
Despite the friction, both countries remain bound by broader defence and trade frameworks, including NATO and the upcoming review of the US–Mexico–Canada trade agreement. However, analysts say the suspension of the defence board signals a rare and significant cooling of military cooperation between the two allies.
