The headline and the article seem to be two different things.  Rather than "remain firm", my suggestion to the Canadian government would be more along the lines of "keep your mouth shut and be adaptable".  In some ways the US is just catching up to Canada's protectionist attitude.  Canada has long been a lousy free-trader when it comes to areas like medical services, agricultural products, or simply subsidizing favoured businesses with government grants.  And the US has tired of being the market for all of the worlds cheap goods.  But as the playing field shifts, we are still in the best position to take advantage of the US market, especially if we keep our mouth shut and don't get all preachy about our neighbours.  
And with regard to Russia's President Putin, who I'm no fan of, Trump has simply looked on the store shelves to see whose products are putting Americans out of work, and decided it would be better for the US to be friends with Russia, and enemies with China.