China is crystal clear in its position towards Taiwan. It is a break away province of China that needs to be recaptured. To date the strategy to bring Taiwan back to mother China has been political and economic, but I am sure that the PLA has a war plan to take Taiwan by force. The calculus is then, will the Western world intervene militarily; yes or no.
I would suggest that the moment China is sure that they won't be opposed they will launch the invasion. I think we are getting closer and closer to that moment .....