China has a different policy against the countries which are or have been aggressors against it and different ones against which it has been an aggressor against. This tweet from Indian Defense Analyst, Brahma Chellaney shows that amply:
China seeks yet another apology from Japan for its past aggression but asks India to “look forward” and not recall the 1962 Chinese invasion
— Brahma Chellaney (@Chellaney) October 24, 2012