The latest generation of the Dongfeng 21D (DF-21D)[1]…is a supercarrier killer according to experts on China's armaments. The missile can be launched from land and strike an aircraft carrier 900 miles away.

Toshi Yoshihara, an associate professor at the U.S. Naval War College asserts that now "China can reach out and hit the U.S. well before the U.S. can get close enough to the mainland to hit back."

Considering the implications and significant threat of China's new generation of carrier-killing missiles, Yoshihara foresees the possibility that they "could have an enduring psychological effect on U.S. policymakers. It underscores more broadly that the U.S. Navy no longer rules the waves as it has since the end of World War II. The stark reality is that sea control cannot be taken for granted anymore."

[1] Background on Dong Feng 21 missile series
http://en.wikipedia.org/wiki/DF-21