It's a complex subject, but one of the things that usually doesn't rise to the surface of the discussion is the water supply afforded by the ice and snow from the himalyaian mountains. This feeds the holy Ganges river on the Indian side of it, which is not just necessary for the irrigation of the subsequent river valley in order for the agriculture necessary to support life, as with pretty much every river valley that gave rise to civilizations of yore. The holy Ganges, btw, also brings valutable silt from the mountains back down to the soil for fertilizer. A very large portion of India is arid desert where there isn't much growing to be had, and so comes with it the accompanying poverty and dirt hovels and the rest. On the other side of these mountains lies Tibet. Why would Red China seek to culturally subjugate Tibet and build high speed rail into it so as to make subjugation easier? Who cares about a bunch of yak milk tea drinkers in some remote mountains? Well, China is also mostly a desert. China needs the water. This is why the boundary between India and China is so contentious and why China has an imperative to control the local Himalyaian population. So where does the Dalai Lama come in? Well obviously the US needs to exploit resource scarcity in order to maintain control over Red China, and the US is run in recent years variously by trotskyite, alinskyite, or other flavors of communists, and the answer for communists is always to agitate and foment a revolution. This is why the CIA makes use of this inclination to keep trouble stirred up between Red China and Tibet because the loss of water supply would be detrimental to Red China's aims for global power.