Instead of taking the spoils of war they returned all Indian military equipment . If it were Americans and British in the shoes of China, they will bringback those weapons and display in museums, and each soldier will keep one as war trophies. Anything of vaue the West are known to bring them home. China on the other hand do not play by the western standards of being barbarians. India is our neighbor and as token of reconciliation Chairman Mao did the right thing to ease the pain of Indian superego. The younger generation of Indians dont know about this but those who were in the know when it happened are thankful.
Unlike the North Vietnamese who were helped by China during their fight against France and America, they were ungrateful , In just four years after taking the whole Vietnam their ego become too big. Flushed with hate against local Vietnamese Chinese they began to purge them out. Deng Xiao Peng saw a growing Asian style pogrom and had to act fast so war with Vietnam happened in 1979.