But do you really know they are with you?
The people around the McMahon side with India not out of any fondness, but rather a fear of losing religious freedom. Given the casual racism of mainstream Indian media against them and their cultural identity apart.
China has been actively courting these people and trying to assure them of their religious rights if they were to come under Chinese governance. These people already see that their future would literally be brighter with China.
The thing that strikes most people visiting the border is how the Chinese side is lit and the roads excellent while the Indian side is dark and the roads crumbling.
Now before people start claiming BS, this is the assessment given by a Tibetan Tibetologist living in India giving a lecture in England.
See: Tsering Topgyal (London School of Economics)
Full lecture here
A Conference on ?Revisiting the China-India Border Dispute? (with podcast) China-India Border Dispute