Hi, dude. I wanna remind you, Aksai Chin is part of China's Xijiang Region now. And there is no Indian residents there.
So what? It was still annexed illegally, because it is part of Kashmir. Though the state itself may be disputed between India and Pakistan, neither of the two countries disputes the fact that Aksai Chin is part of Kashmir.
While lots of tibetans living in Tawang. What's more, one of the Dalai was born in Tawang.
No, Indians live in Tawang, and Tawang residents have Indian passports. So what if one of the Dalai Lamas was born in Tawang? One other Dalai Lama was also born in Mongolia, so is Mongolia part of China too? Lol!
In any case, China refuses to recognize the authority and institution of the Dalai Lama, so to use that institution to put forward a territorial claim on India is absurd.
How do you know the Tibetans dont want it back?
Which Tibetians? The one that you say are living there? They seem to be satisfied with the status quo. They've never been riots in Tawang unlike in Lhasa or other places under Chinese control.
If you were honest in asking yourself that question, you might have asked how you can be sure that the Tibetians in Tibet want to be part of China?
Xizang(Tibet) was not occupied by force, but peacefully liberated through negotiation. You can check up your history book if fight occured in Tibet in 1951.
According to my knowledge, Xinjiang and Tibet are two different territories. And Tibet was not "peacefully liberated", since the Tibetians have, since the "liberation", tried multiple times to "liberate" themselves of Chinese control. The documentation, photos, videos etc are there for all to see. The near extinction of the Tibetian cultural heritage, monastaries, and killings of monks during the Cultural Revolution are also well documented.
P.S.again, The J&K area itself is disputed.
The ownership of J&K is disputed, not its boundaries.