Not long after “Hockey Night in Canada” began on the big screens of a bar in Windsor, Ontario, fans in the arena could be heard delivering an icy message as the visiting team’s national anthem was played. They booed, long and loud.
The visiting team was the Minnesota Wild, the anthem was “The Star-Spangled Banner,” and the game in Ottawa on Saturday was taking place hours after President Trump imposed heavy trade tariffs on Canadian imports.
Windsor is the automotive capital of Canada, and a city where the flag lauded in the booed American anthem can often be seen flapping beside its Canadian counterpart. With Detroit just across the border, A.T.M.s in Windsor disburse both U.S. and Canadian dollars.
And so Mr. Trump’s decision to impose damaging 25 percent tariffs on most Canadian exports and 10 percent levies on energy exports has set off waves of anger and worry in Windsor, and a sense, for many people, of deep disappointment and helplessness.
The tariffs, a stunning departure from the norm in modern relations between the two countries, has raised concerns about a swift shutdown of local auto plants, as well as car factories in Detroit across a river that at some points is only a half-mile wide.
Mr. Trump’s suggestions, repeated again on Sunday, that Canada abandon its sovereignty and throw in its lot with the United States merely added insult to injury. Canadians in Windsor viewed the American president’s idea as — to put it mildly — profoundly unneighborly.
“What is he going to do to us?” wondered Navita Peters, a clerk at a convenience store, as she price-scanned a newspaper with a large photo of a Canadian maple leaf flag on the front page. “It’s unfortunate for the businessmen, but we’re all going to eventually suffer.”
Ms. Peters, who moved to Windsor 25 years ago from Trinidad, said: “It is upsetting, but what can we do? I am proud to be Canadian.”
Lana Payne, the president of Unifor, a union that represents many of Windsor’s autoworkers and employees in other industries across the country, said that since Mr. Trump’s tariffs were announced late Saturday afternoon, she had been deluged by messages.
“A lot of Canadians are waking up this morning absolutely enraged and trying to figure out why their closest ally in the world would do this to them,” said Ms. Payne, who estimated that about 120,000 of her union’s members work in jobs that depend on exports, primarily to the United States. “I never thought I would see this in my lifetime.”
Windsor had appeared to be on the upswing.
After many years of new auto investment going to other places in Canada or, more commonly, Mexico and the southern United States, Stellantis spent 1.89 billion Canadian dollars (about $1.3 billion) to retool a Chrysler assembly plant in Windsor to make electric vehicles alongside gasoline-powered ones. With 4,500 employees, and thousands more expected once a third shift is added, the factory is the hub of the auto industry in Windsor.
And out on the city’s eastern fringes, a 5 billion Canadian dollar (about $3.4 billion) battery plant owned by Stellantis and LG is under construction, with one part already in operation.
Now, instead of anticipating growth, local companies are anxiously waiting to see if they can hold onto what they already have.
Flavio Volpe, the president of the Automotive Parts Manufacturers’ Association, a Canadian trade group, said that Windsor’s many auto parts makers receive weekly orders from automakers based on the production schedules of assembly plants in both Canada and the United States. Now, he said, auto companies are likely to tell parts makers with U.S. orders “that they need to eat the 25 percent.”
Since absorbing the tariff would mean losses of 15 percent to 20 percent for most parts companies, most will probably decide to stop shipping, Mr. Volpe said. Carmakers, too, would have to dramatically hike prices to consumers to offset tariffs on finished cars shipped from Canada.
“How are you going to book a loss every day?” Mr. Volpe asked.
George Papp, the chief executive of Papp Plastics, a parts maker headquartered near the Detroit River in Windsor, said on Sunday that he had yet to hear from any auto companies.
“It is becoming obvious that this is less about punishing Canada or Mexico and more about restructuring revenue for the United States,” Mr. Papp said. Other nations may soon also find themselves hit by American tariffs. “Canada and Mexico are the world’s examples of what’s to come,” he said.
Because auto plants often keep in stock as little as 24 hours’ worth of parts, assembly line shutdowns are expected to quickly follow any suspension of parts shipments. The Stellantis plant in Windsor, which makes minivans and muscle cars, is among those facilities at risk, since it relies on components sent from the United States that use Canadian parts.
Even before Mr. Trump made the tariff order official, and the Canadian government responded with tariffs of its own on American products, some people in Windsor were discussing boycotts.
At a cafe adjacent to the distillery where Canadian Club whisky is made — and largely exported to the United States — two men could be heard loudly discussing their options. They ruled out taking any vacations in the United States, and even vowed not to cross the river for Detroit Tigers games once baseball season begins.
Under official orders, American beer, wine and sprits are to be pulled from the shelves of government-owned liquor stores. One supermarket was running paid posts touting the Canadian origins of some brands of pasta and frozen French fries. And online advertisements by Canadian airlines for trips to sunnier U.S. winter destinations have been met with derisive comments and calls to vacation in Canada.
While economic concerns predominate, Windsor residents also worry about the harm the dispute poses to the close relationship they have long enjoyed with the United States.
“Detroit’s our backyard,” Drew Dilkens, Windsor’s mayor, said, sitting in a meeting room with a view of the American city’s skyline.
Mr. Dilkens said Canada did have “cards we can play” in retaliation, but that the prospect gave him no pleasure.
“We want to be friends, like we have been for hundreds of years,” he said. “We’re not looking for a battle.”
