Bro where are you from? I dont think you really have a good grasp of how powerful the US military machine is. Not trying to be a dick but its true. Let me guess, you are going to bring up Iraq? Vietnam? Irrelevant. Iraq was a war to make money. We werent going all out obviously because they werent a real threat in any way. If they were, we would have turned the entire country into glass in a matter of hours.
In a war with any country, nuclear or non nuclear, America is not losing. Simply not. Either we are winning with ease, or nukes start flying and we take our enemy down with us, and make their country a giant crater in the planet that will not be inhabitable for the next 100,000 years.
A war of US/Canada vs rest of the world is like a streefight between Mike Tyson vs 20 10 year olds. They may get some kicks in but its only a slight annoyance until they are all slaughtered.
Do you think China actually stands a chance? I would LOVE to hear you explain how.