Comment by CMay

It's multiple things. Yes, the automotive manufacturers matter not just for business sense, but because manufacturing base is important to be able to leverage in case of a war. Manufacturing lines played key roles in WW2.

In addition to that, since we're on the car angle, Chinese EVs are basically just privacy nightmares. I mean, all cars are at this point, but that's why we definitely don't want Chinese ones coming across the Canadian border and ending up all over the place.

In the end there are in fact legitimate national security concerns that the tariffs address and Canada risks weakening those. So, that is the actual answer to why.