But there are a few obvious actions that Beijing could take that would constitute overt militarization of its Spratly Islands. First, China could station or provide for the regular rotation of military aircraft through Fiery Cross, Subi, or Mischief Reefs. Second, it could station or regularly rotate PLAN vessels through its new island port facilities. Third, and most concerning, it could deploy advanced missiles to the islands, including the DF-21D (often dubbed the “carrier killer” and most recently referred to as an “assassin’s mace” at Beijing’s September 3 military parade). Ideally, U.S. and regional leaders would be able to dissuade China from building up its islands well before it considers rotational fighter or medium-range missile deployments, but these alarming developments would constitute militarization in the third degree.
Read more: http://nationalinterest.org/feature/american-strategy-the-south-china-sea-time-define-13914?page=2