Japan Halts Aegis Ashore; Resumption Looks Unlikely

Locations of the two intended Japanese Aegis Ashore batteries.
Credit: Colin Throm/AW&ST

BEIJING—Deployment of two planned Lockheed Martin Aegis Ashore anti-ballistic-missile batteries in Japan looks improbable, following a decision to indefinitely suspend the program because of potential danger to civilians.

Defense Minister Kono Taro said rectifying the problem—risks from falling boosters—could take more than a decade and cost more than $2 billion. Announcing the decision to halt the deployment process on June 15, he said that he needs to think about what to do next. He suggested no way of resuming the program.

Since the batteries were supposed to take over from Aegis destroyers in providing nationwide ballistic-missile defense, one effect of the decision is to diminish Japan’s deployable naval capability after the middle of the decade. Calling for an alternative to using destroyers, the navy said the ships could not maintain coverage in bad weather.

But Kono suggested that Japan will still deploy two Lockheed Martin SPY-7 radars that it ordered in November for the Aegis Ashore batteries; they may go aboard new destroyers.

The defense ministry discovered in late May that, contrary to a government promise to local residents, boosters of the SM-3 Block 2A missiles from one of the two sites would not always fall onto a military training area, Kono said. The battery was to be built in that training area.

At first the government expected software modifications could ensure the boosters would fall into the training area. Now, following discussions with the U.S. side, the government has learned that hardware would also need to be changed. Kono suggested that physical changes would have to begin with the missile and flow on to the other parts of the system, notably the Mk. 41 vertical launch system (VLS).

Raytheon and Japanese companies developed the SM-3 Block 2A, which is controlled by Lockheed Martin’s Aegis system.

Japan decided in 2017 to buy the two batteries, later confirming that one would be installed at each end of Honshu. In the face of the North Korean ballistic missile threat, deployment of the systems has been regarded as urgent, with the government aiming for delivery in 2025 and Lockheed Martin trying to accelerate the program.

For the time being, the destroyers will keep doing the job that Aegis Ashore was intended for, the minister said. This makes the destroyers vulnerable—tying them down in restricted areas of the sea—and prevents them from deploying freely to defend other ships against aircraft and missiles, which they were built to do.

“We believe equipment that is independent of the weather will still be needed to replace Aegis ships,” navy chief Adm. Yamamura Hiroshi told reporters. Bad weather can drive ships off station, he said.

Japan has already contracted to spend ¥178.7 ($1.664 billion) on Aegis Ashore.

Speaking to reporters, Kono would not go so far as to say that the program was canceled, but his assessment was so bleak as to suggest little alternative.

“It took 12 years to develop SM-3 Block 2A, with the Japanese side paying ¥110 billion and the U.S. probably paying at least as much,” he said. “I think that if a new missile is developed, it will need that much money and time. And if its shape is changed, it is natural that the VLS could also need modification.”

“In considering that, and in view of the [prospective] cost and time period, the process of deploying Aegis Ashore has been stopped.”

Asked by a reporter whether deployment of Aegis Ashore would be possible with the booster problem resolved, Kono said that “this system” could go aboard ships. He apparently referred to the anti-ballistic missile capability of SM-3 Block 2As.

The government said danger from falling boosters arose only for shots from the battery planned for the southwest of Honshu. But deployment of the one for the northern end of the island has also been stopped. As for the possibility of finding another location for the southwestern site, Kono said ensuring a booster fell in any particular area would be hard, so deployment at any site would be difficult.

It is not entirely clear why a location close to the coast facing North Korea is impracticable; from the northern Honshu site, boosters were expected to fall into the sea. The government has previously implied that chosen sites had to already be in government ownership, presumably to avoid the difficulty of buying land. Only two were considered for the southwest.

The government has not explained why going ahead with the northern battery alone is not practicable. And one more issue that notably went without discussion in the press conference was whether, if North Korea was firing a possibly nuclear ballistic missile at a Japanese city, the small risk to people from falling boosters might be justifiable.

As for the radars that are on order, Kono said: “The SPY-7 radar we have been planning to introduce has very high performance, so it can be used in various ways other than with Aegis Ashore … You can use it if you have more Aegis ships.”

And the cost of developing SM-3 Block 2A would not be wasted, since the destroyers can use missiles of that type, he said.

Japan commissioned its seventh Aegis destroyer, Maya, in March. One more is under construction.

Bradley Perrett

Bradley Perrett covered China, Japan, South Korea and Australia. He is a Mandarin-speaking Australian.