Don't mistake talking about a thing as advocating for that thing. It leaves you completely unable to process international politics, and frankly, a lot of other news and discussion as well. If you can only think about things you approve of, your model of the world is worse than useless.
The countries wouldn't fire nukes against each other's mainlands but maybe against each other's fleets. Pretty likely
I don’t think geographically restricting a war is even possible, really. The US’s typical game plan involves hitting the enemy’s decision-making capabilities faster than they can react. That goes out the window if we can’t hit each other’s mainlands. A war where we don’t get to use our strongest trick and China keeps their massive industrial base is an absurd losing one that the US would be totally nuts to sign up for.
Anyway, we and China can be perfectly good peaceful competitors.
Destroy the other country?
Take it over?
Be in a 1984 style „fake“ war forever?