Adm. Robert Willard told Japan’s Asahi Shimbun newspaper that he believed the Chinese anti-ship ballistic missile program had achieved “initial operational capability,” meaning that a workable design had been settled on and was being further developed.

Known among defense analysts as a “carrier killer,” the Dong Feng 21D missile would be a game-changer in the Asian security environment, where U.S. Navy aircraft carrier battle groups have ruled the waves since the end of World War II…

Years of tests are probably still needed before the missile can be fully deployed, he said. The system requires state-of-the-art guidance systems, and some experts believe it will take China a decade or so to field a reliable threat.