Considering that Japan already has the SM-3 missile fielded on their Aegis ships the acquisition of Aegis Ashore batteries makes since over competing ballistic missile defense systems such as THAAD:
An Aegis Ashore missile-defense system is tested at the Pacific Missile Range Facility in Hawaii in May 2014. COURTESY OF THE MISSILE DEFENSE AGENCY
The Japanese government is pushing ahead with plans to boost its missile defenses in response to the growing threat from North Korea.
The nation’s Cabinet on Tuesday approved the acquisition of two Aegis Ashore systems capable of defending the entire country against incoming missiles.
“North Korea’s nuclear and missile development has become a more serious and imminent threat to our security, entering in a new phase,” a Cabinet statement said. “It is necessary to drastically expand our ballistic missile defense capability in order to continuously and persistently protect our country even during normal circumstances.” [Stars & Stripes]
You can read more at the link, but the 2023 timeframe is reportedly when the batteries will be in place. So this is definitely not a near term mitigation to North Korea’s ballistic missile threat.
