I think I mentioned this in the US vs world thread but my friends had an argument about the same thing. Chinese guy said China because they had the people's army, as well as a billion+ people. Plus Chinese work hard and can produce masses of cheaply produced weapons, ammunition etc. Indian friend said India would win because they had elephants.
Honestly, if I were the US I would side with India. If you're massloads in debt with China, wipe out China and that debt is gone. Logical no?