Right now it's being used to build out the Air Defense Identification Zone they claimed over the south china sea a couple years ago and back up their claim with the threat of shoot down. By projecting force over the South China Sea, they, in essence, use the islands to turn it into their own private lake and effectively take over what are considered international waters render moot the ongoing arguments at the UN regarding islands and mineral rights. If the geological estimates concerning the amount of oil in the SCS are correct, it's a major coup and has the possibility of turning China into a net oil producer.