You have any idea of the sealift capacity needed to move an invasion army of sufficient size to conquer a continent? The US and Britain were challenged to put one together for D-Day, and that was from a secure base only a few miles from the target. The Chinese would have to cross thousands of miles of open water.
While it is theoretically possible US ground forces could be tied up in a civil war, the US Navy is more or less by definition unable to participate effectively in such a war, and might have something to say about whether a Chinese invasion fleet could make it here.
Don’t underestimate the actual logistics required for maneuver warfare in limited warfare is different than that in total war.
Should a foreign force begin with assessing their resources to project an invading force, then mold the environment upon which the advance to lessen their opposition, they may well be poised to invade a foreign shore.
We probably won’t see something like Normandy or Tarawa, but might well observe an invasion of Mexican illegals, coupled with well controlled columns similar to the US advance into Baghdad.
Just look at the restrictions this admin. put on our soldiers fighting a freakin war.