It's a tax increase which can be (and is being) mis-portrayed as something that the seller pays, when in fact it's the buyer that pays it.
In practice what Trump did was institute the equivalent of an additional 25% sales tax for all Americans when they buy goods manufactured in Canada or Mexico, but because this tax is usually payed by companies (which do most of the importing) and most people aren't at all familiar with how Import/Export works, he seems to be getting away with portraying it as a tax on Canada and Mexico.
(The concern of those countries is not that they pay more - which they don't - it's that a selective "sales tax" that only applies to products they export to the US makes their products less competitive on price when sold in the US, hence they will sell less which is bad for their companies)
I've seen some theories around that the purpose of this significant increase in tax is to pay for the tax cuts for the wealthy that the Republicans are passing.
My theory is that they want to control the North-West Passage, which due to climate change will become a high traffic trade route. Something currently dominated by Panama (which he also wants). So they're putting pressure on Canada now.
Greenland is in a similar situation but I think there may also be oil and such there as well.
Didn't they say climate change was a hoax or was that just for their brain dead cult followers? Amazing how easily they are manipulated. It's like Republicans captured all the media then spewed shit to dominate them, but hey, it works magnificently.
Trump administration says fentanyl though very little moves across the Canadian border. They're using it to declare a national emergency and therefore bypass Congress.
From Canada's perspective it's to weaken Canada's perspective it's to weaken the Canadian economy so that it's easier to annex.
Does anyone actually know why we are putting tariffs on Canadian goods?
I think his objective is to try and damage Canada's economy, but I'm not sure exactly why. Apparently he really is serious about the "51st state" thing along with the Greenland and Panama thing. He's just that megalomaniacal. He wants to be like Putin.
Because Trump has a toddler's level of understanding of how international trade works, along with a toddler's tendency to throw tantrums when challenged.