Canada starts collecting retaliatory duties of up to 50% on hundreds of American products on September 8, a bad turn for workers and shoppers on both sides of the border.

• Ottawa is hitting roughly 900 US products, covering $20–30 billion of goods, after talks broke down.
• Washington has threatened its own round, including a jump toward 50% on Canadian cars and a wider net over car parts in January 2027.
• Canada is far more exposed: three quarters of its exports go to one customer, the United States.
• The old grievances are driving it — Canada's dairy quotas, the endless softwood lumber fight, and a digital tax aimed at American tech firms.
• Mark Carney is expected to run on the fight itself, campaigning against Trump rather than settling, while courting Europe and China.

Outlook: Prices on cross-border goods start rising within days, and the January car tariffs are the next flashpoint unless both capitals back down.