Canada

I think you can just as easily flip that on its head.

USA consistently weaponizes its companies through sanctions. If a country wants to be part of the global economy you need to do business with USA banks (eg SWIFT) and tech, and if your country is sanctioned, it cannot. Speaking of tech, the tech companies actively participates in wiretapping and that’s really old news - who knows what they’re doing today.

China is typically careful about throwing its weight around because of its high dependency on exports and limited deployment capability of its army.

In terms of a shooting war with the USA, China has a strategic advantage in being able to shut down Canadian transportation remotely, agreed.

I think recent events have shown, however, that there’s no guarantee that the USA would automatically be on the side of Canada. I’m thinking more it’s more along the lines of how Germany and Austria were “on the same side” in WWII ie Annexation.

China has shown repeatedly that it’s willing to be an absolutely belligerent asshole, and weaponize it’s companies in that undertaking against most of it’s trading partners.

Categorically false. I certainly wish our "loved oligarchs" weaponized good value products against me. That you feel entitled to not be competed against, doesn't make competition unfair or any of your adjectives.

China would benefit more from taking such action in a global conflict. If China got into an actual fight with the USA, crippling parts of the Canadian economy would be a great way to harm the US directly

Far smarter for Canada would be to not engage in our usual US force amplification sycophancy, or let US draft Canadians as cannon fodder for their war, while still letting the US pay us for industrial support for their war. China will win, US will collapse soon enough even without war, but it would be diplomatically acceptable to China if we just exploited the US.

Any country bricking electronics/vehicles in Canada is declaring war on Canada and making us side with whoever is against that country. It's good reason to not give Canadians explosive pagers, but don't wrongly assume which country is more desperate to resort to terrorism.