A deal that appeared within reach has collapsed into a tariff fight, exposing how quickly the U.S.-Canada economic partnership can turn from integration to confrontation.

Negotiators had sketched an agreement to lower U.S. sectoral tariffs on Canadian autos, steel, aluminum and lumber. But late Friday, the talks snagged over whether medium- and heavy-duty vehicles — including Ontario-built Ford F-350 pickups — would receive the same relief. Canada says Washington removed those vehicles from the reduced-tariff category at the last minute; U.S. officials viewed Ottawa’s demand as a new condition. ¹

Prime Minister Mark Carney argued that excluding trucks made no sense: “No rationale,” he said of a result that would leave Ford’s Ontario plant outside the deal. Flavio Volpe, who heads Canada’s Automotive Parts Manufacturers’ Association, accused the Americans of trying to split the industry and suggested the broader aim could be to “get rid of auto manufacturing in Canada.” ¹

The breakdown swiftly became punitive. The United States imposed 50% tariffs on roughly $20 billion in Canadian goods, while Canada set Sept. 8 for dollar-for-dollar counter-tariffs and targeted support for exposed industries. Carney said Washington had turned “economic integration as a weapon” and warned that the old relationship would not return. ²

Washington tells a different story. U.S. Trade Representative Jamieson Greer said the administration had offered cuts on sensitive tariffs but was responding to Canadian retaliation: “Our interest is in protecting American workers and protecting American supply chains.” ²

The two sides agree on one point: the dispute now threatens more than a single truck classification. With no further talks planned, it clouds the coming review of the USMCA and risks higher costs on both sides of the border. ²