In late December, Japan’s government approved acquisition of two Aegis ashore missile defense systems. Aegis ashore is the land-based missile defense component derived from the same technology that sails on board new-construction Arleigh Burke–class destroyers. It includes SPY-1 radar, Mk-41 vertical-launch systems housing SM-3 missiles, and linkages to C4I systems. The two land-based assets are not expected to be in service until 2023, at which time they will begin working in concert with Japan’s already formidable air defense umbrella of Patriot surface-to-air missiles and a growing number of JMSDF Aegis destroyers outfitted for missile defense. The new locations for Japan’s Aegis ashore elements have not yet been finalized, but they almost certainly will be positioned to optimize defense against the ever-present threat from North Korean missile attack. Aegis ashore is also in use by the NATO alliance, which has operated a system in Romania since 2016 (pictured here), and a second system is expected to come online in Poland later this year.
By Eric Wertheim