The missile defense strategy is of the utmost importance among Japan’s security issues. The Japanese land and territorial waters have been protected by seven see-based Aegis destroyers, and one more Aegis destroyer, which becomes the eighth, is scheduled to be commissioned by March 2021. Furthermore, the government planned in 2017 to deploy two land-based Aegis Ashore missile defense systems, one in Akita Prefecture and the other in Yamaguchi Prefecture, and the deployment was scheduled to be completed by 2021. The two Aegis Ashore systems, which would have been complementary to see-based Aegis destroyers and land-based PAC-3 interceptor missiles, were expected to have the capacity of countering the missile threat by North Korea.
However, on June 15, Minister of Defense Taro Kono abruptly announced that the government had suspended the deployment of the two land-based Aegis Ashore systems in Akita and Yamaguchi prefectures. He cited technical issues and high costs as the reasons for the suspension. Technical reliability to enable rocket boosters to fall within the missile launching site and not on the surrounding area could not be ensured, and in order to ensure the technical reliability, it was found out that not only improvements of the software but also modifications of the missiles were required. The government calculated the overhauls would cost an extra $1.8 billion and take ten years to implement. Defense Minister Kono decided it was unreasonable. Now the government needs to work out a new strategy on Japan’s missile defense.
On September 4, Defense Minister Kono attended the joint committee of the Research Commission on National Security and the National Security Division of the Liberal Democratic Party (LDP). The Minister explained regretfully to the joint committee members regarding the details of the suspension of the two Aegis Ashore systems, and expressed his view on Japan’s future strategy for missile defense. Participating members expressed their opinions and some made critical comments.