Military might, economic force, tearing up two centuries of treaties — it will take more than a pencil and eraser to redraw the Canada-U.S. border.

U.S. President Donald Trump has repeatedly stated he’d like to annex Canada, dispose of at least one international boundary treaty, and “get rid of that artificially drawn line” known as the border.

His first salvo has been a trade war, which escalated Wednesday when he imposed 25 per cent tariffs on steel and aluminum imports from all nations. Canada retaliated with “dollar-for-dollar” tariffs.

Trump wants what we have, said Jack Cunningham, an assistant professor of International Relations at the University of Toronto’s Trinity College.

He wants us under his thumb, an “economic satellite” of the United States. For Trump, all treaties and agreements are up for debate. America had its proponents of a similar “commercial union” in the late 19th and early 20th centuries.

“Basically, what they wanted was a set of economic arrangements where Canada would be reduced to a storehouse of raw materials for what was then the emerging American industrial economy,” Cunningham told the Star. “I think Trump would like something along those lines.

“Though, since he’s an utter ignoramus, he doesn’t really understand the economics or the history.”

History of border goes back to 18th century

The Canada/U.S. border stretches for 8,891 kilometres, across four Great Lakes and between seven Canadian provinces, one territory and 10 American states.

The International Boundary Commission (IBC), a binational organization created under the Treaty of 1908, which Trump wants to kill, maintains the monuments and remote borderlines.

“The proper definition and demarcation of the boundary is still as essential for sovereignty as it was throughout the history of boundary establishment,” the commission notes on its website. “It prevents local misunderstandings that could lead to disputes.”

Efforts to officially define the border between the British colonies and the new United States began in 1783 with the Treaty of Paris, which ended the American Revolutionary War.

“The Treaty of Paris is pretty hallowed by the standards by which treaties are judged,” said Cunningham. “Most of the other relevant treaties are old too — 19th century.”

“There’s never been any notion of reopening them, until now. This is unprecedented.”

Canadian historian Craig Baird said the 1783 treaty essentially set the border at the Great Lakes, with the sprawling Province of Quebec giving up what are now parts of Michigan, Indiana, and Illinois.

A 1794 treaty settled outstanding boundary disputes with mapping and surveying, he told the Star.

“It figured out, at least in southern Ontario, exactly where the border was,” said Baird, who hosts the Canadian History Ehx podcast. “That’s why Detroit was on the American side and what eventually became Windsor was on the Canadian side.

The Treaty of 1818 established the border west of Lake Superior. The United States and Britain settled on the 49th parallel, partly because it was easy to survey.

“A straight line, essentially from Lake Superior more or less all the way to the Pacific Ocean,” said Baird.

The 49th parallel has come to be used as a kind of shorthand to define the Canada/U.S. border, but about 70 per cent of Canadians actually live south of it.

Toronto, Ottawa, Montreal, and all of New Brunswick, Prince Edward Island, and Nova Scotia are south of the 49th parallel. So is Windsor.

What is Trump threatening?

“The only thing that makes sense is for Canada to become our cherished Fifty First State,” Trump posted Tuesday on his social media platform. “This would make all Tariffs, and everything else, totally disappear.”

Trump has repeatedly called Canada the “51st state.”

“It’s very offensive, because we’re the United States’ closest ally, closest friend,” said Baird. “Now we’re feeling betrayed. Along with things like tariffs, there’s talk of claiming the Great Lakes for themselves and redrawing the border. It’s throwing in the face of 200 years of progress and cooperation to create this 8,000-kilometre-long undefended border.

“It’s really terrible, even if it’s just bluster.”

In February, Trump advisor Peter Navarro pushed U.S. negotiators to discuss redrawing the border with Canadian counterparts.

Trump has said his plan is to use “economic force” to annex Canada.

He initially imposed wide-ranging 25 per cent tariffs against Canadian imports, but then quickly paused most of them until April after the stock market plunged due to the turmoil.

On Wednesday at 12:01 a.m., however, Trump imposed 25 per cent tariffs — a rollback from a threatened 50 per cent — on steel and aluminum from all countries. Canada and the European Union immediately announced retaliation.

At 12:01 a.m. Thursday, Canada imposed additional 25 per cent tariffs on $29.8 billion worth of U.S. imports. That retaliation follows $30 billion worth of levies Canada put in place following Trump’s first round of announced tariffs in February.

Trump also wants to tear up a 1908 border treaty between Canada and the U.S.

But Cunningham said the treaty is “not that consequential.” The threat is likely just a means of exerting leverage, he said.

“It’s basically 19th century diplomacy,” said Cunningham.

“Each great power in its sphere of influence would throw its weight around against the other states in that region. That’s basically his attitude. He thinks the United States should be able to bully everybody else in the Western Hemisphere.”

Trump’s menacing overtures are so concerning that U.S. Congressman Seth Magaziner of Rhode Island last week introduced the No Invading Allies Act. Along with his threats against Canada, Trump wants to take over Greenland and the Panama Canal — and has refused to rule out force to do it.

Can Trump unilaterally redraw the map?

No.

“There’s no way that a country like Canada is going to say, ‘Okay, you can have Southern Ontario,’” said Baird.

“So, there’s no way that the border would be redrawn. It’s really just all talk. The only way to do it would be a mutual agreement between both countries, which would never happen.

“Or an invasion.”

Redrawing the map would require the parties to agree and engage in deliberations, or for one side to “unilaterally renounce it” and seek renegotiations.

“But Trump would not find willing takers,” said Cunningham. “Were he to go that route, everybody would point to the fact that this border has been well-accepted, well-understood for over a century. People have conducted themselves accordingly.”

If negotiation and diplomacy failed, and Trump was intent on redrawing the border, Cunningham said the next step could be military aggression.

“But it’s hard to see even Trump going that far,” he said. “Although I’ve got to admit, I’m among those who have thought at times there were limits to how far he would go and being surprised by his exceeding them.

“So, we are in somewhat uncharted waters.”

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