The reality is Tibet has had a complex relationship with China for centuries. I learned from reading the citation below: that even Buddhism in Tibet probably came from intermarriage with a Buddhist princess from China. With the reign of the Mongols that Buddhism in turn gets transmitted to the conquerer, humanizing Kublai Khan, who established the Yuan Dynasty.
It gets messier after that with the Chinese actually at times *reinforcing* the rule of the Dalai Lama's and defending the monasteries from invaders and looters and at other times and other centuries taking it over. Rinse and repeat ...it gets still messier and more bloody than today. BOTH Tibetans and Chinese went back and forth in killing off Dalai Lamas based on politics in the 19th century. The relationship with the most recent Dalai Lama happens to be a bad one. Some others had much better relatioships.
The British also conquered Lhasa and controlled parts of Tibet for a while. India has claimed parts what Tibetans claim too. But like American Indian lands never reverting, those lands are now firmly entrenched. And like Native American experience, today it is hard to call the relationship abusive or to say Indians are forced to give up their identity. The native Americans I know mainstream but directly trace back their culture and ethnicity and are proud of that part of themselves.
Following seems like a pretty balanced and well-written article by a historian, PhD candidate.