The Defense Ministry is considering introducing a new ground-based type of interceptor missile that the United States is developing, in an effort to bolster Japan’s ballistic missile defense system, ministry sources said.
The ministry intends to introduce new ground-based SM-3 missiles, in addition to the sea-based SM-3s that the Maritime Self-Defense Force (MSDF) already possesses, to enhance Tokyo’s readiness to intercept ballistic missiles heading toward Japan. The ministry is expected to allocate tens of millions of yen from the fiscal 2015 state budget for research on the missile.
Since a ground-based SM-3 can defend an area within a radius of about 500 kilometers, three missile posts could cover the whole of Japan. Launch pads for the SM-3 can be disassembled in five to 10 days and can easily be built in other locations.
SM-3s are equipped with a high-performance radar. Since sea-based SM-3 missiles are installed on Aegis destroyers, ground-based SM-3s are dubbed “Aegis ashore.”
In the current ballistic missile defense system, SM-3s installed on Aegis destroyers are intended to intercept missiles flying in space, while ground-based PAC3 missiles are supposed to shoot down missiles that sea-based SM-3s fail to intercept.
Each PAC3 can cover an area within a radius of about 20 kilometers. Altogether, 30 of the missiles have been deployed across the country, but there are concerns that PAC3s could not respond if a massive number of ballistic missiles were to be simultaneously launched toward Japan.
As such, the ministry intends to double the MSDF’s Aegis destroyers equipped with ballistic missile defense capabilities from four to eight by fiscal 2018. The capabilities of sea-based SM-3s are almost equal to those of ground-based SM-3s. However, since the MSDF is also supposed to use Aegis ships for air defense operations, such vessels cannot concentrate on ballistic missile defense operations. This played a part in the ministry’s intention to improve Japan’s ability to intercept ballistic missiles by introducing ground-based SM-3s.