India would be largely routed before the US or any western allies could even establish a presence. US could deploy B1’s and offer some air support from regional bases, but by the time we had any sort of military presence of numbers on the continent, much of India would be overrun.
China doesn’t just have a huge military force, they are disciplined trained and determined... China also has a large population conditioned to obey and from birth and for thousands of years, believes China is destiny. India would be overrun quickly.
Yes they would be on defensive, and I am sure some civilians would put up resistance, but I don’t think you would see some giant rising up by the civilian population of India against the Chinese if they invaded.
India is about as close to herding cats as you can get and still call yourself a nation state.
One thing is for sure, if China and India were to go to open war with each other... the world population would see a major decline rapidly... roughly 1/4 of the worlds population is in just those 2 nations... So it would be ugly and bloody whatever happened, but I see no way India can in any way take on China and win in any sort of conventional war.
Conventional warfare?
The average age in India is 20-years-old.
The average age in China is 40. That’s all thanks to its abortion policy, BTW.
You go muster an army of 40-year-old grandpas, and I’ll fight you with an army of 20-year-olds. Let’s see who wins.