The nemesis here isn’t Bucky Dent. It’s Donald Trump. And among Canadians, the two men share the same deprecating middle name.

Since President Trump began his tariff attack against America’s biggest trading partner and closest diplomatic friend, the once recessive gene of Canadian nationalism has become the dominant element of the country’s character.

And because there’s no better symbol of American arrogance and self-satisfaction than the Yankees, the American League Division Series is a ripe platform for a brand of Yankee resentment that can only be matched by — and now may actually exceed — the strain that mutates on Lansdowne Street.

The term “Yankees,” of course, has multiple meanings, few of them endearing. In Boston, it was an expression of opprobrium signifying the onetime governing and financial establishment of the Hub. In the South it means the forces who opposed the Confederacy in the Civil War and laid waste to Georgia and South Carolina. And though in New York it means a ball club based in the Bronx, in Canada the term stands as shorthand for the citizens of the country that twice sent Trump to the White House.

As in: “You Yanks think you can have your way with us.”

And while we partisans of the Olde Towne Team consider ourselves members of Red Sox Nation, this ALDS confrontation, which heads to a crucial Game 3 Tuesday night, has an entire nation rooting for the Blue Jays. It is a distinction with a real difference in the age of Trump.

In sports as in politics, context is everything.

Few south of the border who listened to Trump’s maundering speech to the generals and admirals at the Marine Corps base in Quantico, Va., last week noticed that he couldn’t resist another comment about making Canada the 51st state. It was a throwaway line, and swiftly his stream-of-consciousness ramble went on to something else.

But up here, that line threw the country into another paroxysm of worry.

A few days later, the Globe and Mail newspaper carried a long essay titled “How It Could Start,” worrying that a Trump annexation attempt might take the form of the dispatch of American warships through the waterways of the Canadian Arctic. A fellow NATO country suddenly was consulting international navigation agreements and the United Nations Convention on the Law of the Sea.

All this worry was occurring among the people who, until Inauguration Day, were America’s best friends. And who gave us a son who brought us basketball — James Naismith was born in what is now Altmont, Ontario — and then went on to embrace America’s baseball. Indeed, the Red Sox’ top minor league team from 1965 to 1967 was the Toronto Maple Leafs, one of whose members was the relief pitcher Sparky Lyle, who became a Sox fan favorite … until he donned Yankee pinstripes, became an All-Star, and won two World Series.

There’s a deep well of resentment here against New York, which until the president decamped to Mar-a-Lago was his home town and which is the site of the golden escalator ride that changed North America.

Canadians have long resented that their most gifted writers and artists felt they had to go to New York to prove themselves. As early as the beginning of the 20th century, Canadian writers began migrating to New York, there to test their work against the arbiters of culture in Manhattan, which by then had replaced Boston as the center of the literary universe.

Now all that resentment and irritation has an outlet. The Blue Jays are on the brink of eliminating the Yankees from the playoffs, a prospect that would spread vast amounts of joy.

Meanwhile, Canadian Yankee fans are the focus of extreme disfavor.

“There’s a real cost to being a Yankee fan in this atmosphere,” said Sam Marinucci, an accountant raised in the canal town of Welland, Ontario, 25 miles from the American border, who as a child religiously listened to Yankee games on Buffalo radio. “You cannot imagine the online abuse I’m getting.”