Canada has been a very weak partner for decades. As one politician said, we are like that guy who eats the meal at the restaurant, but goes to the washroom when it is time for the cheque to be paid.
The Americans sent an oil tanker to traverse the North West Passage decades ago in defiance of our claims that it is our, rather than international waters, and China is openly contemplating doing the same in the event that the passage became ice free. The US has offered a place at the table numerous times for theater and continental ABM defence, which Canada has always rejected (yet somehow we still manage to become outraged when someone points out that without Canadian participation, US ABM defence will involve interception over Canadian airspace). Even the tariff brewup is strategic in nature, the US is applying economic pressure on China and closing back doors for Chinese imports to enter the US market unaffected by the tariff barriers, but we somehow imagine we are not supposed to be caught up or involved in a US-China dispute. I'm sure you can think of other examples.
If Canada refuses to step up, then we as Canadians should not be surprised if others will step into the gaps we are leaving, or ignore our interests as irrelevant or even opposed to their own. After all, what are we going to do about it anyway?
A tremendous amount of what is happening is really the results of decades of smugly imagining we are "above" the fray, or are somehow able to use moral superiority to achieve results (how well did that work with Saudi Arabia?). Until the Canadian public gets their heads out of their collective a***s, and starts demanding the political establishment take things like foreign affairs and defence seriously like an advanced G7 nation should, there will be no end to this. President Trump has a very good chance of re election in 2020, and his policies will last well beyond his leaving the White House in 2024 (as a minimum, it will take the new Administration at least one term to move thing back to the way they were prior to 2016, and the voting public will harshly constrain their ability to move), so we will be suffering the effects of tariffs and trade barriers until 2028, or be forced to sign a much less beneficial deal based on the bilateral US-Mexico trade agreement.
And so long as the government and "Laurentian Elites" continue to sit on their hands WRT things like Canada's petroleum and petrochemical industry, breaking down internal trade barriers or actually moving to take advantage of the TPP and CETA, we have essentially cut off all our room to manoeuvre. The blame isn't to be found in the White House, but right here at home.