Verv wrote:If China were suddenly interested in human rights
Fundamentally, it is an issue of constructing a (multi)nation-state.
China as a nation-state is a recent invention. Its origin and early influence can be dated at the end of the 19th century and early 20th century, but it was not until the founding of the People's Republic that China constructed anything that resembled a modern European nation-state, which is essentially something forced upon the Chinese by the spread of Western capitalist world-system (of nation-state).
This construction involved defining clearly delineated borders and exercising military and civilian authority over its territory, which China previously has not done as a non-nation-state. This is why the early decade of the People's Republic was a period of tense territorial disputes with its neighbours, and it is also when China categorised, sometimes very arbitrarily, different nationalities/ethnicities.
The Europeans has gone through this stage a few centuries ago and it wasn't bloodless as European nation-states were given birth. In fact, it is almost always a history of genocide and ethnic cleansing.
China, as a recent nation-state, is still living with the legacy of all the tensions inherent in it, navigating the relations of the dominant ethnic group(s) with other minor ethnic groups struggling for autonomy and independence.
This is not to endorse or excuse what China is doing though.