It goes back to the Russia / Nato position. If the US wants to play around with China, China has nukes and will use them if threatened. so troop numbers at a certain point becomes irrelevant. but China has a population of more 3 times that of the US.
And remember the population of of a combined Canada and North America.... how many illegal immigrants are there that will go back to Central and South America, how many left wing anti war activist, how many people are willing to fight given the current divided nation. There are so many variables.
The Chinese in a curious way still have the great firewall. The coastal and more affluent areas might now what is going to happen next but most of them do not.
The fact that the CCP have changed their lives so much for the past 30 years, majority are willing to take the stand. Nationalism have been on a rise in China for the past 10 years and it is mostly thanks to the West.
They don't even need to convince their own citizens or put out propaganda and say the West is trying to fuck them over.
All they need to do is to allow a decent amount of them to use VPN, go to Western forums and check Youtube videos and comments and bam ! Free nation building for Chinese citizens by the West for the CCP.