The United States imposed 50 percent tariffs on about $20 billion of Canadian goods in the early hours of 22 August, after three days of talks in Washington failed hours before the deadline. The list runs from wine, furniture, dairy and cement to clothing, fishing rods and hockey equipment, covering roughly five percent of what Canada ships south each year.
Canada matched it. Mark Carney announced retaliatory tariffs dollar for dollar from 8 September, at rates of 15, 25 and 50 percent on steel, dairy, appliances, agricultural equipment, pulp and paper, plastics and electronics. Canada says the American measures now cover $27.6 billion of its goods and its counter-tariffs cover the same figure in reverse.
Each side blamed the other. US Trade Representative Jamieson Greer said Canada declined to finalise the deal under terms agreed earlier that week and that new demands and walk-backs had upended a careful balance. Carney said last-minute changes in the American terms were unfair, uneconomic, and called into question the reliability of any deal. He later described the situation as being attacked. Greer’s summary was blunter: we’ve said enough.
To punish Canada, Trump reached back to Section 338 of the Tariff Act of 1930.
The two countries sold each other $880 billion of goods and services last year. No further talks are planned. Carney travelled to New York this week with no Trump meeting scheduled, and American import restrictions on selected Canadian alcohol, dairy and motor-vehicle products are due to take effect on 29 September.
Set beside the Mexico story from last week, this is the same negotiation with the opposite outcome, and the difference is instructive.
Mexico watched this collapse and chose accommodation, sprinting toward an interim deal before the midterms and tabling investment-screening legislation nobody had formally demanded. Canada held its position and is paying for it in real money. Which approach was correct will not be knowable for years, and anyone claiming otherwise is guessing.
What is knowable now is the mechanism by which a deal dies, and every supplier who has ever negotiated with a much larger customer will recognise it precisely.
You spend weeks on the terms. Everything is agreed. Then, on the last afternoon, the other side introduces a change. It is presented as a small clarification. It is not small, and accepting it would cost you more than the contract is worth. You now face a decision with no good option: sign something that damages you, or walk away from months of work and the revenue attached to it.
The important detail is that the timing is not an accident. Last-minute changes work because sunk cost is at its maximum and your capacity to start again is at its minimum. Recognising the move is the entire defence, and the only real counter is being willing, visibly, to leave the table.
Canada left. The cost is fifty percent on a slice of its exports and a frozen relationship with the buyer of three quarters of what it sells.
The tariffs were meant to be leverage. They became the arrangement.
