When President Trump sent out his infamous tweets last month attacking Canadian Prime Minister Justin Trudeau, I happened to be on vacation in Nova Scotia.

We started introducing ourselves by saying “Yes, we’re Americans, but it’s not our fault.” Canadians mostly reacted with a mixture of pity and amused contempt. “I like watching Trump better than David Letterman,” said a bakery shop owner in the tiny town of Digby, a place that is famous for its scallops and is more than a thousand miles northeast of Detroit.

Maybe, I thought.  But David Letterman never had nuclear bombs.  I read a lot of science fiction when I was a child, including stories about parallel universes where dinosaurs still roamed the earth or the Nazis had won World War II. Suddenly, I felt that I was in a parallel universe, one where Canada had suddenly become our enemy and North Korea was our “friend.”

I wanted, and still want, to go back through the looking glass. I have always found Canada to be a highly interesting country, and have been amazed and embarrassed at the way we “lower Americans” take it for granted.  For many years, we treated Canada with condescension when we bothered to notice it at all. I was once present when the wife of a Detroit magazine publisher asked a Canadian diplomat why their country didn’t just merge with the United States.

Can you imagine asking a French diplomat why his country didn’t just merge with Germany?  Later, the Canadian official told me he was used to comments like that; they didn’t bother him anymore.  However, I think we should all take a few minutes to try and see things from a Canadian perspective. Canada is a nation that is geographically the same size as ours and has the same number of time zones, if you leave out Hawaii.

But it only has a little over one-tenth as many people – 36 million to our 326 million. Canadian journalist Allan Fotheringham once said that for Canadians, our relationship was something like a mouse being in bed with an elephant. The mouse doesn’t sleep very well.

Back in the 19th century, Canada constantly worried about being invaded and annexed by the United States, with good reason. In recent history, we’ve too often taken it for granted.

The wife of Canada’s ambassador to Washington in the 1980s said “maybe we should invade South Dakota, or something” to get us to notice them.

But the fact is that our economies have long been completely intertwined.  Imposing new harsh tariffs on Canada would badly hurt Michigan and the Midwest. The value of what moves over the Ambassador Bridge alone is as great as America’s entire trade with Japan.

What’s especially bizarre is that while the United States does have a large and troublesome trade deficit, Canada is one of the very few countries with which we have a trade surplus. It is hard to understand President Trump’s logic in going after Canada.

The United States may have some legitimate grievances with Canada; I could argue that we should be pressing Ottawa to spend more on defense. But our two nations, while different, are probably closer and more interwoven than any other industrialized countries in the world.

Messing that up would be a dreadful and disastrous mistake.