American trade is nearly worth half of Canada’s total GDP. something like 75~80% of total Canadian exports go to the US. if they actually retaliate in force they could be dooming their country to an economic crisis if Trump is spiteful enough. so far the Canadian tariffs have only touched about $30B worth of goods, or 7% of the total trade.

Canada - America trade amounts to a little over $920B https://crsreports.congress.gov/product/pdf/IF/IF12595

Canadian GDP is a little over $2.1T https://data.worldbank.org/indicator/NY.GDP.MKTP.CD?locations=CA

We’re talking nearly half of their GDP. In addition, half of Canadian foreign investment comes directly from the US. They will continue to be integrated into the US economy, even if Trump doubled the tariffs tomorrow.

And that’s because Canada, and Mexico to an even higher extent, are completely reliant on US trade. They both have no real choice but to grin and bear it. They will of course speak out publicly for the domestic audience but things will continue more or less status quo for the foreseeable future.