December 21, 2005: Japan, concerned over the potential threat from Chinese and North Korean ballistic missile, has agreed to participate in the development of an advanced version of the U.S. Aegis (ship based) anti-missile system. Japan would contribute a third of the $3 billion cost, and develop the nose cone, and two-stage starter motor for the new version of the SM-3 missile. Existing models of the SM-3 are serving on American Aegis warships stationed off North Korea. These ships can use their Aegis radars, and SM-3 missiles, to intercept North Korean ballistic missiles.