If there is a World War 3 though I guarantee the USA will get involved. If Trump wins 2020 (and I hope he does) then he will send the Navy to help India and secure the supply chain across the Atlantic, down the Cape of Good Hope, and into the harbors of Chennai and Kolkata.
Trump will also do anything to re-establish his dominance from the Pacific Ocean all the way to Hong Kong and Taiwan. There will be American military presence everywhere. Japan will help India. South Korea will be the land base for R&R for soldiers in the Far East. Taiwan will be used for air raid missions.
If China even thinks about going to war with India, then the USA will absolutely get involved.
If you want you could sign up for the military right now so you can get a head start.
Not to mention if Pakistan is fighting alongside China against India, then basically the entire Muslim world will be fighting with the Chinks. Iran, Syria, Jordan, Lebanon, Palestine, Egypt, Somalia, etc. The only exceptions are probably Saudi Arabia and the Gulf states (Kuwait, UAE, Bahrain, Qatar, Oman) but even then if Trump keeps up hostilities towards Muslims, then they will turn against Americans too.