You think that's disproportionate? Imposing a tariff in response to <i>nothing at all</i> is disproportionate.<p>On a percentage basis, it's merely a finite response to an infinite action. That doesn't seem unfair to me.<p>Don't expect your enemy to play by your rules when you're the one who made them an enemy.
I'm not canadian, but my understanding is that this is beyond just the tariff. It is in addition of the general attitude and (lack of) diplomacy from the US government towards Canada for the past few weeks.
This is an important part of the article: "Canada accounted for only 1% of the company's total sales, Whiting said, so the company can withstand the hit."
If you're going to play the trade war game for equal damages then neither side should play. Trade wars should be about disproportionate damage until the other side quits.