On June 15, Japanese Minister of Defense Taro Kono announced that Japan would suspend plans to deploy the Aegis Ashore missile defense system due to “cost and schedule” concerns, triggering a government-wide review of Japan’s missile defense program.
The plan, which would deploy Aegis Ashore systems in Yamaguchi and Akita prefectures, has faced multiple schedule delays. The Yamaguchi deployment plans were previously delayed over concerns that Aegis interceptors could drop their booster rockets outside of the training range; according to Kono, software modifications were inadequate for eliminating this possibility. Plans to emplace Aegis Ashore in the city of Akita also faced local opposition. Following the suspension, the government of Japan announced its intent to continue deploying its sea-based Aegis missile defense systems while reviewing future requirements.