Kind of an insensitive question, but a sincere one.
They have already devastated our manufacturing base. It's gone.
China has conflicts with India, Japan, Philippines, Taiwan, Hong Kong, Tibet, Singapore. All of which would love to shave some of that exported labor from China, in a post conflict.
77% ethnic Chinese,
All China has to do is lightly arm about 20 million unmarried young men, send them south to kill all the Vietnamese males and their children while granting them the women as their spoils.
China may have been actively trying to export its ethnic Han to other countries
A war with China would mean nuclear war.
Actually, the PRC have no allies at all, in the region.