China huminliated India in 1962 war. We lost because of Nehru's lack of vision, his lack of strategic thinking and spying by communists in India. We had plenty of brave army jawans and officers that could have kept china engaged for many many years, not thru open war but thru proxy wars. But Nehru caved in like a coward.
Besides usual public war agreements, then congress leaders to save their seat of power in Delhi entered into a secrete agreement with then chinese military generals that India will be a vassal state of China for 65 years. Since then congress whenever in power in Delhi has adopted beaten-up obedient cow like attitude in front of chinses bullying. Congress has systematically ignored India's strategic interests.
China poses a great threat to India thru its support to pakistan, support to maoists, control of rivers to east India etc etc.