How about if China buys Greenland or otherwise acquires a massive port on Greenland. Maybe China builds one of the world's largest military bases on Greenland with a century deal.
China is going to end up being every bit as powerful as the US ever was, both economically and militarily. Nothing will be off the table in what's coming. Russia has never had a true global projection navy, China will have a navy that is plausibly going to be both larger and more powerful than the US navy with full global reach. That global reach will include the entire North and South American region.
If you're the US you look to lock down Greenland and Panama, for starters.
What if China builds a port in Canada? Does that mean the US has to invade?
In practice Greenland and Denmark have been quite sensitive to these things are unlikely to open a Chinese naval base. Which is one of the things that's sad about this - why attack one of your most faithful allies and wreck NATO in a way that horries most of the democratic world and delights Moscow? Not really the US's finest hour.
China is going to end up being every bit as powerful as the US ever was, both economically and militarily. Nothing will be off the table in what's coming. Russia has never had a true global projection navy, China will have a navy that is plausibly going to be both larger and more powerful than the US navy with full global reach. That global reach will include the entire North and South American region.
If you're the US you look to lock down Greenland and Panama, for starters.