Canada could do that. It'd be profoundly stupid, as Canada would be hurt far more than the US and EU would be. (On the US/EU side, prices would go up, with eventual repercussions. On the CA side, no money would come in for those export industries, and you'd quickly have tons of people laid off and those companies clamoring for government assistance.)

But yes, Canada could do that in hopes of getting a cut of potential future shipping money. Their politician probably aren't that foolish, though.