China and Pakistan suffer from concentration of population in only few areas. Whole of china can be taken out by just attacking few of their cities in east coast just like Pakistan wherein we can target only Sindh and Punjab to kill over 80% of the population. Chinese must remember that. 1962 happened when we trusted China. We don't trust them anymore. So their will be no 1962 but 1971, china will loose Tibet and with that their entire nuke force as that is where they have kept them.
Russia and the United States are the only two nations that can do a credible countervalue strike against China.
China has over 660 cities with more than 200,000 people (300 cities with over a million); most of them sprawling manufacturing hubs linked via excellent infrastructure. They're spread out over 40% of China's landmass (an area about the size of the entire country of India
). India has 120 nukes, of which a sizeable quantity would be aimed at Pakistan; what's more, India is adding long-range ballistic missiles at about the same rate China is adding advanced S-300 and S-400 ABM systems, which means its paltry response would be diluted even further. At most, maybe 20 or 30 Indian could land on China. China, from bases in Sichuan, Gansu, and Anhui (not in Tibet) could dump over 300 nuclear warheads on India if it so chose to do so--this, on top of whatever nukes Pakistan launches towards India.
In short: in an Indo-Pak nuclear confict, India will be bending over backwards to keep China from intervening, because a Chinese intervention would lead to instant annihilation of India as a functioning state--and I doubt Russia or the United States would punish China for responding to an Indian first strike.