Tibet was de facto independent for a while, but it re-joined China voluntarily circa 1950. About 10 years later, with some help from western agitation and assets, the theocratic ruling class felt too threatened by development empowering their serf population and sought to secede in order to maintain their fiefdom. Mao sent in the PLA and crushed the secessionist revolt.

You really can't "no u" this one because of Imperial China, the PRC's claim to Tibet is completely valid. You'd probably have more luck trying with Xinjiang, though evidently that is viewed as slightly played-out now.