Japan might deploy the land-based Aegis Ashore missile defense system in Akita and Yamaguchi prefectures to address North Korea's aggressive provocations, a government source said Saturday.
Under the plan, the Ground Self-Defense Force would operate the Aegis Ashore system at Self-Defense Forces facilities in the two prefectures. But some in the Defense Ministry oppose the plan, the source said.
Aegis Ashore uses the same components as those fitted on Aegis-equipped destroyers in the U.S. and Japanese fleets. Japan would only need two Aegis Ashore batteries for full coverage, but to avoid an overlap the government plans to deploy one battery each in eastern and western Japan.
Placing a battery in Yamaguchi, however, would leave some of the southwestern islands in Kagoshima and Okinawa prefectures vulnerable, the source said. So the government will continue studying candidate sites.
Under Japan's current missile defense scheme, Maritime Self-Defense Force Aegis destroyers are to stop missiles in the outer atmosphere using Standard Missile-3 interceptors. If they fail, the Air Self-Defense Force's Patriot Advanced Capability-3 surface-to-air interceptors are the next line of defense. The introduction of Aegis Ashore is meant to further reinforce the system.
Compared to the sea-based defenses, the land-based Aegis Ashore makes it easier to prepare for missile intercepts because the system will be permanently installed.