The problem is that Trump is unable to define and follow smart tactics, because he's too impulsive.
Canada, Mexico and China represent 40% of U.S. exports, add European countries and it's more than 60%.
He could have taken them one after the other, with a reasonable chance to get some benefits from it. But he's too stupid. It's not a trade war with only Canada, it's a trade war with more than 60% of U.S. exports.