Why only Tibet? Even Chechnya will never gain independence from Russia. There are many such examples. This is primarily because the recognition of Tibet as an independent country by the UN will be promptly vetoed by China. Same with Chechnya.

The situation with Kosovo is different from that of Tibet. Tibet is under direct control of a major veto-wielding world power - China.

I am not too sure that Kosovo will gain independence either. As things look now, the world opinion notwithstanding, Russia will veto it. Russia cannot simply support an anti-Serbia move. We will have to wait and watch what happens.

Because China is behind Tibet and everyone knows how powerful China is. No other country can interfere in Tibet conflict. Even India is taking cautious steps.