US tariffs on Canada is a way of removing preference subsidies to Canada and boosting US industries.
Canada is more dependent on US than US is on Canada. TIme would show the clear picture but what we know for sure is US is more self sufficient than Canada. There might be some price increases in short term but in long term, US would be more economically powerful.
So in your eyes it does not actually care whether the United States and Canada had had a very healthy and constructive relation as neighbor nations? the only things with matters is to make the United States to grow no matter what? Not matter their allies feel betrayed and left alone against tyrants and other treats?
This is not only a ongoing commercial and tariff war it is about keeping democracy and Republican values alive in the west and it would seem Trump is willing to throw into the trash those valued and principles for the sake of more power and further increase his personal fortune. He has already broken many day-one promises on immigration and inflation.