The biggest 'enemy' of Canada is not America(s). It's the Canadian govt itself. Most Canadians cave into their tribal instinct of 'us versus them' and cannot see past that own manipulative govt.
Canada has not only proportionately significantly more trade restrictions (between countries) compare to US, but it also have significant restrictions to trade and free market within Canada: example quotas on milk, dairy, beef and chicken. There are more taxes at every stage of a transaction with little benefits ( yes people mention 'free' health care but it's another subject). Relatively unaffordable housing mostly due to taxation (For example the tax part of condo in Toronto/Vancouver is cumulatively about 35%) etc.
Just to be clear both govts of US and Canada are tyrannical. Americans on an average distrust their govt more than Canadians - hence they overall do better in keeping their govt overreach in check.
Its one thing to correct the meaning of the word "self sufficient" and its straight up bad faith to talk past the actual meaning of the comment
If you think Canadians have more nationalistic pride than Americans, you seriously need to get glasses.
Americans literally pledge themselves to their country every day of school.
Literally every American has been force fed nationalistic pride propaganda since their first days at school, continuing for 12 years.
Never mind the average American. They’re all stuffed full of it.
That's an understatement. Hypothetically if Canada were isolated from the world, it would regress in the quality of life in 10 years. The most capable Canadians have moved out, mostly to the US. The average Canadian has unwarranted sense of nationalistic pride about them (compared to their neighbors).
Isolate US from the world, and assuming that the govt does not meddle too much with local businesses, in 10 years they will bounce back to being more self sufficient than it is now.