TORONTO  This is a big country with only one thing on its mind: Donald Trump. South of the border, no one is taking seriously the notion that the president wants to make Canada the 51st state. To Americans, it’s a joke, a throwaway line, a distraction, just Donald being Donald. Up here, it is an “existential threat.” In a few days here, I heard that otherwise overemployed phrase several times. Placing a maple leaf amid the 50 stars of Old Glory is less likely than the Maple Leafs winning the Stanley Cup, which the embattled Toronto hockey team hasn’t done since the presidency of Lyndon Johnson (everybody here remembers what everybody in the U.S. has forgotten: that Johnson manhandled Lester Pearson at Camp David in response to the Canadian prime minister’s questioning of LBJ’s Vietnam War policy). Even when cooler heads prevail and dismiss the Trump 51st-state remarks, there’s real, and justifiable, concern about the president’s threat of a 25% tariff on goods from Canada, perhaps by raising them by 2% to 5% a month. Already Canadian banks and businesses are including “tariff event” clauses in contracts. Ontario Premier Doug Ford warned the tariffs would jeopardize a half-million jobs in his province alone.  Canadian leaders are examining possible retaliatory actions, including steep duties on steel, orange juice and potash (only available in large quantities in Russia and Saskatchewan, which provides 87% of American imports). Also in the mix: energy, though Alberta Premier Danielle Smith has indicated that she’ll oppose tariffs on her province’s oil and gas. In recent days, there’s been talk of as much as $100 billion in retaliatory tariffs, or “dollar-for-dollar” tariffs that would match American duties.  Worries about American attacks — rhetorical, economic or military — on Canada date to 1775 and the early 19th century. Thomas Jefferson, not known for his aggressive side, said the conquest of Canada would be “a matter of marching.” Actually, American soldiers did march into Canada during the War of 1812. It didn’t work out that well. Queenston Heights is still a part of Ontario, not New York state. Franklin Delano Roosevelt is remembered here — revered, really — for extending the American security umbrella to Canada in the run-up to World War II. “Having shared insecurity in the 1920s and 1930s,” University of Toronto professor of Canadian history Robert Bothwell wrote in his 2015 “Your Country, My Country: A Unified History of the United States and Canada,” “Canada and the United States shared security from harm and want, for individuals and families.” But despite the many pleasing words from American leaders — “By mutual respect, understanding and with good will,” Dwight Eisenhower said, “we can find acceptable solutions to any problems which exist or may arise between us” — Canadians have been skeptical of American presidents before.  Prime Minister John Diefenbaker despised John F. Kennedy, a sentiment the American president returned with enthusiasm. Pierre Elliott Trudeau, father of the current prime minister, and Richard Nixon were often at odds; the 37th president called Trudeau a word that rhymes with “glass bowl.” The current prime minister for years has sparred with Trump, who called him “two-faced” and described him as “Governor Justin Trudeau of the Great State of Canada.” Now returns Trump, who is regarded here as a threat to Canadian sovereignty and prosperity. “I have a real problem with some of the things Donald Trump is saying,” former Prime Minister Stephen Harper said, adding that “it doesn’t sound to me like the pronouncements of somebody who’s a friend, a partner and an ally, which is what I’ve always thought the United States is for our country.” Then another former Canadian prime minister, Jean Chretien (“ready at the ramparts to help defend the independence of our country”), weighed in with a 91st birthday op-ed in the Globe and Mail newspaper: “To Donald Trump, from one old guy to another: Give your head a shake! What could make you think that Canadians would ever give up the best country in the world — and make no mistake, that is what we are — to join the United States?” There are, to be sure, enormous economic consequences to this growing divide between the two countries. But in a broader sense, the cultural consequences for both are even greater.  At risk is the friendship — personal, familial — that allows the countries to share a 5,525-mile undefended border and the largest trade relationship that both countries have.  Listen to some of Trump’s presidential predecessors, even Johnson, who had his complaints with Canada: “No nation in the world has had greater fortune than mine in sharing a continent with the people and the nation of Canada.”  Or Ronald Reagan: “We’re more than friends and neighbors and allies; we are kin, who together have built the most productive relationship between any two countries in the world today.”  Or Bill Clinton: “We’re neighbors by the grace of nature. We are allies and friends by choice.” Already Canada is unsettled by the political upheaval in the U.S. that Trump represents and has stoked. “Ordinary Canadians must prepare, not for war but for chaos — economic, political, social, cultural,” Stephen Marche, the author of “The Next Civil War,” a look at the implications of American political divisions, wrote in Macleans magazine. “If your neighbour’s house is on fire, yours eventually will be, too.”  The result of all this attention on the U.S. and its leaders is to focus attention on Canada — not only what it isn’t (the U.S.) but what it is (a far different culture and country). “That doesn’t depend upon us being different from the United States, or any other democracy for that matter,” Andrew Coyne wrote in the Globe and Mail newspaper. “We do have our differences, of course, but mostly we are alike as inheritors of the Western liberal tradition. Great — let’s strive to be the best exemplars of that tradition: the freest, the fairest, the most democratic, and so on.” That challenge is greater than tariffs. It’s about self-knowledge and recognizing differences that Americans — hard-pressed to distinguish between Dawson City (the Yukon) and Drummondville (Quebec) — don’t see. “Canadians believe Americans know everything about us,” said Laura Dawson, executive director of the Future Borders Coalition. “They don’t.” David M. Shribman is the former executive editor of the Pittsburgh Post-Gazette. The post David M. Shribman | Canada Can’t Shake Trump appeared first on Santa Clarita Valley Signal.