I know our history very well, do you? You have to read Chinese books to know your history.
Minority groups in Xinjiang and Tibet added up arre less than Beijing city's population and Beijing is far from the most populous Chinese city. Hong kong has a small population which are divided into pro and anti government groups, but they always do their own things and mainland China just ignore them cause they have no impact in China. Speaking of breaking up, China will be the last country in the world to break up, but Turkey is always breaking up, never really united, some part of Turkey even today is like a war zone.