It’s easy in this case because an invasion by sea is a big target, and you can hit them without any chance of them claiming they’re attacking their homeland. It will mostly be which side has more missiles or boats. I don’t know if they will actually do it because it’s not just a single invasion. They would have to violently occupy a medium size country. That would require several million soldiers to be stationed there and supplied from the mainland. They would have to do some conscription or spend a year gathering troops. It would be very obvious. And the part where they have 0 combat experience won’t help. They won’t be ready for at least another 5-10 years. Currently the ukraine war has showed that currently drones favor the defensive side and so that is bad for China. In the future that could change but right now any full scale invasion is unlikely.