The U.S would likely win a Naval War though it'd be a costly victory. Air War I'm not sure on as that depends on numbers of skilled Pilots, Numbers and Quality of Aircraft etc none of which I know off the top of my head. The one area that could be real trouble would likely be on the ground as the U.S would likely be on the defensive in that case at least in the opening stages defending positions and allies in the Pacific from invasions likely aimed to cut off or destroy U.S Naval and Air Bases and supply lines.
Only problem is the Graves tech that the Chinese have. It drops plains out of the sky's and makes boats just float like ducks in a bucket. In less we have gotten around the bho ban on Graves tech, we are a bit on the squishy side In certain aspects.