TOKYO -- Building two Aegis-equipped warships as an alternative to the American-made, land-based Aegis Ashore missile shield would cost Japan 20% to 25% more, according to Defense Ministry estimates compiled Tuesday.
The price tag for two superdestroyers ranges between 480 billion and 500 billion yen ($4.59 billion to $4.79 billion), compared with 400 billion yen for the now-canceled plan to install a pair of Aegis Ashore systems. The figures, based on numbers provided by two private contractors, will be presented to the ruling Liberal Democratic Party's defense committee Wednesday.
The calculation was based on building warships with capabilities similar to those of a Maya-class destroyer. With machine guns, autocannons and missiles, the total comes to 240 billion to 250 billion yen per ship -- about 40% more than the Maya's roughly 170 billion yen cost.
High-performance radars capable of covering all of Japan, likely SPY-7 radars developed by Lockheed Martin, to be installed in the ships push up the cost.
The vessel would need to be several meters longer than a Maya-class ship in order to accommodate the large radar system and other equipment, which requires reworking its overall specifications and such details as the center of gravity. This means additional costs for design, as well as for systems needed to use the radar at sea.
The ministry also looked at the cost of deploying the Aegis defense system on a tanker or other large ship, or on an offshore structure similar to an oil rig, which were among its original proposals.
The former, while costing less than the envisioned warships, would still carry a price tag of 190 billion yen or more. The rig is the most expensive of the four options if equipped with the necessary defenses.
The technical survey did not show any of the proposals standing out from a cost perspective. The government will continue considering its options, focusing on building new Aegis-equipped destroyers, which are easier to handle in terms of speed and defensive capabilities.
The government originally decided in 2017 to deploy the Aegis Ashore system to handle North Korean missiles. The price per battery was initially estimated at 70 billion to 80 billion yen, with two batteries providing round-the-clock coverage for the entire nation.
But this jumped to more than 120 billion yen at the contract stage and was inflated further by efforts to address concerns about booster rockets falling on residential neighborhoods. The total expense per battery ultimately clocked in at more than 200 billion yen.
The estimates show that switching to an Aegis ship will not solve the cost problem. Within the LDP, some say that the focus now should be on China, not North Korea, and argue for switching to a system that can handle Chinese missiles regardless of the cost.