Canada

Canada seems very committed to other allies. Sure, go ahead and try to coordinate with them. Policies, coordinated, that should be announced today:

All US military purchases are paused.
Suspension of military cooperation including expulsion of US personel.
Punishing FDI into the US, with perhaps seizing assets of any related company in Canada. Export tariffs on materials needed for auto industry
Immediate diplomacy with China, to join "delete America" program, and remove tariffs on Canada, more exports, and encourage FDI.
Threaten ROK, JPN, US with relations with DPRK.
Create Government US Export management agency for energy and Potash to ensure good prices, splitting proceeds with Provinces and exporting companies. After tariffs removed, proceeds will go to companies.
Better relations with Mexico including auto sector cooperation. Chinese ships may be needed/helpful for direct trade between our 2 nations. Mexico reorienting their industry to South American demand.
Stop being a rubber stamp for US led council of Americas evil. Better trade/relations with all of South/Central America.

Carney's plan for an all Canadian auto industry is reasonable. Carrots and sticks on industry is needed. Industry fighting back against US is critical. Canada's greater anger level is a big edge, and I/we won't mind significant resources devoted to ensuring auto industry survival. But OTOH, it is a very expensive subsidy for jobs that will be disappearing through automation anyway. 0 imports from US ever as punishment, and opening up to much cheaper cars from elsewhere is likely a better value for Canadians/economy, and a tactic to ensure auto industry commitment.

The basics are to act as if USA is already an enemy state to its colonies. Stop pretending that they will change their mind, because they always hated their slaves.