China needs to push south to the Oil of Indonesia and Malaya -They can not let Vietnam win again. It will be like Genis Khan. Lots will die. US is too far away to give real help. The Chinese Navy and Nukes to threaten the USA will keep our forces out of the fray. Only Japan and India might stop the Red Horde. I believe the Chinese will move on Taiwan first, a blood less take over. Then, land, sea, air and cyber attack after an “incident” Six months will see Vietnam fall. Lots more coming to the USA from Vietnam. Then, will come a move further south. Places threatened: Singapore and oil rich states. China built that navy and they will use it.
I would think that a direct threat to Singapore would bring a US response.