Question: is this asking about a Chinese break-up starting anytime post-1900 and resulting in a Balkanized China today? Plenty of possibilities in that.
I interpreted it as being about a late-20th C to present-day- or are you including a future POD?
Very unlikely, but-Tiananmen? The sight of all those protestors reminds Deng Xiaoping so much of the Cultural Revolution that he keels over with a stroke.
The hard-liners still have most of the control, but those advocating a more moderate approach-Zhao Ziyang and co.- are strengthened by this, especially as the old guys try to cover it up.
The moderates are able to get the news out, and wild rumors fly- Deng has been murdered, arrested, there's a coup... demands grow in Beijing and Shanghai for Deng to appear. Protests grow larger and spread to more areas- the authorities crack down in less visible places, but news leaks out- wilder and wilder accusations are flung.
Finally, the hammer comes down in Beijing- the hard-liners bring in the 27th and 28th armies, the locally based 38th Army comes to the defense of the protestors, civil war erupts, in Shanghai and Guangdong the Party leadership splits- some declare for the reformers, denouncing the "New Gang of Seven" - the "Eight Immortals" minus Deng. PLA units turn on each other....
Not likely,but....