How long would the US last in a war with China?

The Japanese? That went pretty well, actually.

I keep being flabbergasted by the number of people who don’t understand that there’s a VAST difference between invading a country and occupying a country.

Yes, the two are typically linked–but they are two entirely separate actions.

This map gives one starting point for thinking about this:

In what way did it go better for Japan than, oh, say, the war in Afghanistan has gone for the US?

Japan did not conquer even 25% of the country, and it did not have to start with amphibious landings as the US did throughout the war.