CommanderSock CommanderSock:
The PRC can't be allowed to run roughshod to whoever it wants.
Which runs afoul of China's "Middle Kingdom Syndrome" in which the Chinese believe that they have an inherent right to rule the entire world and if only their ignorant inferiors would recognize this then we could all get along.
In short, the Chinese think they have a right to do whatever they want to whomever they want.
Of course, if they want to do whatever they want they first need the capability and the problem with the Chinese is that they are still reeling from the aftereffects of both the Qing Dynasty and Mao and his ill-conceived Cultural Revolution. Their internal and cultural issues are so bad that they can't even mount a successful invasion of the Spratly Islands let alone be able to take on serious world players like India, Japan, Indonesia, the Phillipines, the USA, and etc. in order to get a pass on invading Taiwan.