Tensions swelled in the 1980s amid a growing debate over strategy, when the American leadership of the union shifted toward a less aggressive position while the Canadian side wanted to maintain firm pressure on the auto companies.

Correlates with when a lot of Americans bit down hard on the fishhook of Reaganomics.

Posted before, but key is automakers deciding to increase Canadian production at US expense during tariff war, as best way to return to normal afterwards. Canadians are angrier than US. Destroying Canadian auto sector would result in 0 future car sales in Canada. Big cost advantage potential with energy and materials export taxes to US, and using some of that revenue to subsidize energy/materials to Canadian auto sectors.

Cowering to Trump more than Canada will hurt Auto manufacturers more.