America Just Suspended Its Oldest Defense Partnership; The Canada Decision Breaks 80 Years of Continental Security

The Permanent Joint Board on Defense has operated since 1940. The Trump administration has just walked out of it. That is not a trade dispute. It is a structural rupture in North American security.

The United States has suspended its participation in the Permanent Joint Board on Defense — the bilateral security forum established with Canada in 1940, before America had even entered World War Two — citing Canada’s failure to meet its defense commitments. Deputy Secretary of Defense Elbridge Colby announced the suspension via social media, framing it as a pause pending review of what the forum’s benefits actually are.

The institutional history makes this decision extraordinary. The PJBD was created by Roosevelt and Canadian Prime Minister Mackenzie King at Ogdensburg, New York, in August 1940 — when Britain was under siege and North American continental defense required coordinated planning between the two nations sharing the continent. It has operated continuously for 85 years through every Cold War crisis, every post-9/11 security reorganization, and every previous period of bilateral friction.

Trump has now suspended it over defense spending disagreements.

What Colby Actually Said

Colby’s statement did not frame the suspension as permanent but as a review — an assessment of whether the forum “delivers value” sufficient to justify continued American participation. The language of cost-benefit analysis applied to an 85-year security alliance is itself a signal: the administration is treating foundational institutional relationships as transactional arrangements subject to renegotiation rather than as structural commitments that underpin continental security.

His reference to the gap between Canada’s “hollow claims” and reality points directly to NATO’s two percent GDP defense spending target, which Canada has historically fallen short of. Canadian Prime Minister Mark Carney committed last year to reaching five percent — an unusually ambitious pledge — but commitments and current expenditure are different things, and the Trump administration has consistently prioritized the latter.

The NORAD Dimension Nobody Is Discussing

The PJBD suspension does not automatically affect NORAD — the North American Aerospace Defense Command that jointly monitors and defends North American airspace. NORAD operates under a separate treaty framework. But the two institutions are deeply interconnected in planning, coordination, and information sharing. Suspending one while maintaining the other creates institutional incoherence that military planners on both sides will find genuinely problematic.

Canada’s geographic position makes continental defense cooperation not optional but structural. Russian bombers approaching North America from the Arctic pass through Canadian airspace. Early warning radar installations in Canada are integral to American missile defense monitoring. The idea that the US can manage continental defense without deep Canadian institutional integration is a fiction that geography does not support.

The Pattern This Fits

The PJBD suspension follows a consistent Trump administration approach to alliances: treat them as burden-sharing arrangements where American participation is conditional on financial contribution rather than as strategic assets whose value exceeds any single member’s defense budget.

Canada is America’s largest trading partner, longest border neighbor, and closest intelligence partner. Suspending an 80-year defense board over spending targets is not alliance management. It is alliance erosion — and the consequences will outlast whatever review Colby has ordered.

Disclaimer; Based on Elbridge Colby’s publicly available statement and open-source North American defense analysis.