Tibet and state sovereignty

Here's a link to an interesting article on Tibetans attempting to deal with Han Chinese in their communities. I thought this was pertinent because it brings up the whole issue of state sovereignty.

Here we have an area that, for all intensive purposes, was its own country, but China just came on in and took it over. Despite the rest of the world's allegiance to the notion of state sovereignty, apparently Tibet is immune to this ideal. Why do you think that is the case? Do we just not care about ignoring this norm if the offending country is important to us or is it something that happened so long ago that no one seems to care anymore? It seems to me that for a long time, Tibet just took a back seat to more pressing Cold War issues, and then after the fall of Communism we cared too much about our economic welfare to fight China's control. Anyway, just my own two cents.