Canada-US Trade War: Carney Says US Attacked, Tariffs Hit Prices

From trade dispute to what Carney calls an attack

Canadian Prime Minister Mark Carney has described the latest round of US tariffs as an act of aggression, not a normal trade fight. In August, Ottawa suspended talks after what Carney called "last-minute changes" to Washington's proposed terms. He said Canada would retaliate "dollar for dollar" starting September 8. The next day he told reporters: "You're at war when you get attacked. We got attacked."5 Weeks later, an interview with The New York Times made his framing look more than rhetorical. Carney said his government had studied the "extreme tail risk" of US military action against Canada, while stressing that this was risk management, not an expected outcome.86

The headlines are dominated by talk of war, sovereignty and even invasion planning. For households and businesses, though, the more immediate question is narrower: what do these tariffs cost, who pays, and how long will higher prices last? A wave of new economic research published in early October gives a better answer than the political rhetoric does. In short, the damage is real but smaller and slower than the language of war suggests, and it is concentrated in particular sectors.

What actually happened

The tariffs that set off this phase took effect at 12:01 a.m. ET on August 22, after the two sides missed a negotiating deadline. They cover products ranging from hockey sticks to wine.10 US Trade Representative Jamieson Greer said Canada had backed away from terms agreed earlier that week and had kept up its own retaliation against American goods.10 Carney said Washington "asked too much and offered too little." He named US changes to auto tariff levels as a key sticking point.10

The legal basis is unusual. The administration used Section 338 of the Tariff Act of 1930, which allows tariffs of up to 50% on countries found to discriminate against US commerce.10 The Congressional Research Service says this is the first time the United States has expressly invoked that statute to impose tariffs.17 Unlike earlier rounds, these duties apply even to goods that comply with the US-Mexico-Canada Agreement. Energy, potash, fish, critical minerals and goods already covered by Section 232 duties are excluded. That matters. Canada's most important exports, including oil, gas and potash, are left out, so the measure hits a defined slice of trade rather than the whole relationship.10

Canada responded on September 8 with tariffs of 15%, 25% and 50% on C$27.6 billion of US goods, roughly US$20 billion.17 The measures focus on steel, dairy, appliances, agricultural equipment, pulp and paper, and electronics.10 Washington then went further. A US ban on several Canadian imports, including alcohol, dairy and motorcycles, took effect in late September. It sits on top of 50% tariffs on Canadian dairy, alcohol, steel and aluminum, and 25% tariffs on Canadian-built cars.14 A larger tariff increase on Canadian cars, trucks and auto parts is scheduled for January 1.618

Where the reporting diverges

Outlets describe the size of the conflict differently. Some say both sides imposed 50% tariffs on about $20 billion of goods.16 ABC reported Carney's figure of about $28 billion of affected Canadian goods.10 The gap is mostly a currency issue: C$27.6 billion is about US$20 billion.17 The "equal" description also simplifies things. Canada's package uses three different rates and covers more than 700 US products.14

Coverage also splits on how dangerous this moment is. Mainstream reporting treats the military contingency planning as a sign of how badly trust has broken down. Carney himself said he still talks to Trump "frequently" and sees a path back to negotiations.8 Some commentary on the left reads the same remarks as evidence of a much deeper rupture between the two countries, while noting that Canada still sends about three-quarters of its exports to the United States.2 The more reasonable reading is that Carney is guarding against a worst case while still trying to reach a deal. He has said that a "mutually beneficial trade deal" remains possible.2

The price question: smaller and slower than the rhetoric

This is where the coverage is most useful, and where the tone of a "war" differs most from what the data show.

Harvard Business School economist Alberto Cavallo and co-authors from Canada's central bank tracked daily prices on 112,000 products at seven major Canadian retailers. They studied Canada's 2025 counter-tariffs, which were mostly lifted after six months. Prices of tariffed goods rose about 6% compared with similar untariffed goods. That is roughly a quarter of the 25% levy, and the effect disappeared once the tariffs were lifted.12 Canada's consumer price index rose only about 0.3 percentage points. That is less than half the effect Cavallo measured in the US, largely because Canada's tariffs covered fewer goods and did not push up the prices of substitutes.12

Two Bank of Canada staff papers released in October explain why. One finds that a 25% counter-tariff on US imports raises Canada's overall price index by about 0.66%. A simple cost pass-through calculation would predict 1.25%. Most of the difference comes from consumers switching to non-US alternatives, and some from firms accepting lower margins.13 The gap grows at higher rates: at 50%, the pass-through calculation predicts more than twice the actual effect.13 That matters now, because many of Canada's current duties are set at 50%.

The second paper adds a caveat. About two-thirds of the price effect comes through supply chains, as higher input costs spread through domestic industries. Tariffs on machinery and transport equipment raise final prices the most.11 The authors estimate that differently designed packages of the same import value could have cut the price impact by three to seven times.11 Canada's choice of products is therefore a policy decision with real consequences for consumers.

On the US side, Federal Reserve Bank of New York researchers find that about 90% of the 2025 tariffs showed up in US import prices. About a quarter of a tariff increase reaches consumer goods prices after a year, and around a third of that effect comes from US-made goods, not imports.18 They specifically identify the August 2026 tariffs on Canadian goods as still working their way through, which is pushing the tariff effect on US price levels up again.18 ABC noted that grocery prices remain a major concern for American voters ahead of the midterms.10 The affected US imports include dairy, honey, whey protein, molasses, whiskey and vodka.10

What Canadian shoppers will see

Consumer guides list the categories most exposed to Canada's counter-tariffs: dairy items such as milk powder and whey, honey and molasses, cosmetics, paper goods, clothing, gas stoves and building materials. Rates range from 25% to 50%.19 The duty is paid by importers at the border, so it shows up gradually as higher shelf prices, not as a separate charge at checkout.19 The same guidance notes that for many imports, swings in the Canadian dollar can matter more than a tariff on one narrow category.19 Recent figures show grocery inflation falling to 2.8% from 3.1%. The Bank of Canada's next rate decision is October 28.19

The research points to a clear conclusion. Canada's counter-tariffs will raise prices on specific goods, but probably by a fraction of the headline rates. The effect on overall inflation should be limited and should reverse if the tariffs are removed.1213 The bigger danger is not at the grocery store. It is in factories and jobs.

The real damage is industrial

The Stelco case shows how. Its US owner, Cleveland-Cliffs, announced layoffs partly blamed on US tariffs. The company said demand in its traditional markets fell almost 25% in the second quarter compared with the 2024 quarterly average.3 Carney accused the company of betraying workers and noted that Cleveland-Cliffs CEO Lourenco Goncalves had publicly backed the 50% steel tariffs.3 He said federal money had been offered to preserve jobs.3

Autos are the next pressure point. Carney told the Times that the auto sector has been integrated across the border for his entire life and that breaking it apart makes no sense.6 The January auto tariff increase puts a deadline on the dispute.18 Carney has resisted pressure to use energy as leverage, even though Canada supplies about 60% of US oil imports.8 That restraint suggests Ottawa is not trying to escalate further.

The bottom line

Carney's description of an "attack" fits the strategic situation: a 1930 statute used for the first time, duties applied to USMCA-compliant goods, import bans, and auto tariffs scheduled for January.1714 For consumers, though, the evidence points to a slow price increase, not a sudden shock. On both sides, about a quarter of tariff costs typically reaches shoppers, and the effect fades when the tariffs end.1218 The heavier costs are falling on steelworkers and auto suppliers. Whether Ottawa and Washington get back to talks before January will matter more than any single grocery bill.