The Aegis Ashore Missile Defense Test Complex at the Pacific Missile Range Facility at Kauai, Hawaii, conducts a flight test. Photo: US Defense Department

Japan’s cancellation of the two Aegis Ashore missile defense systems was not caused by local complaints about the basing of the missiles, despite what Japanese politicians claim.

It looks more and more as if Japan does not want to be “caught in the middle” in a confrontation between the United States and North Korea, or a confrontation with China.

According to Japan’s defense minister, the country will rely on Patriot and ship-mounted Aegis for missile defense and protection of critical base and infrastructure assets in Japan.

Patriot is not an answer to protecting either Japanese or American forces and their bases. Patriot is a poor point defense system and Japan does not have enough of them, even if they worked perfectly to protect all Japanese and American bases.

Today, the US maintains major airbases at Misawa, Yokota and Kadena on Okinawa. Japan bases its F-35s at Misawa and will soon become the world’s second-largest F-35 operator. There also is a US Naval air facility at Atsugi and the large US naval base at Yokosuka, which is the forward-deployed base for the US aircraft carrier USS Ronald Reagan.

The Japanese arguments for canceling Aegis Ashore are mainly about dangers to civilians. But there are just as many dangers from military and civilian jet aircraft to local communities, and the Patriot is a bad substitute – if it can be considered that – for Aegis Ashore for many reasons.

Japan originally bought two Aegis Ashore systems to provide full-time coverage of all Japan’s territory against missile attacks from North Korea or China.

No full-time coverage

The existing sea-based Aegis systems in Japan’s inventory, even if enlarged with more ships in the future, cannot provide full-time coverage. Aegis Ashore can.

On Thursday, June 25, Defense Minister Taro Kono said the decision was reached by Japan’s National Security Council to cancel the Aegis Ashore systems slated for deployment in Akita and Yamaguchi. 

Japan’s National Security Council is an organization under the Foreign Affairs and Defense ministries. It is led by the prime minister and the chief cabinet secretary and includes the foreign minister, the defense minister and an NSC chief adviser.

The cancellation order, therefore, reflects an all-government decision under the prime minister.

US Defense Secretary Mark Esper and Japanese Defense Minister Taro Kono speak with reporters at the Pentagon on January 14, 2020. Photo: Handout/Agencies

Officially, at least, as explained by Defense Minister Tara Kono, the reason for the cancellation was that the Defense Ministry could not guarantee that, if a missile was fired at an enemy target or in a test, it would not land on a civilian population center. 

According to Kono, the Defense Ministry could not find any way to ensure missiles land on a military base – presuming they missed a target that was overhead, or failed in flight – rather than a civilian population center.

This kind of objection to missile sites is not unknown. Years ago in the United States in the days when Nike air defense batteries were located in or near local communities, objections were raised that the sites themselves were dangerous. 

In the 1950s, 14 Nike missile bases were built between New York and Philadelphia to protect against a Soviet bomber attack. On May 22, 1958, while crews were installing missile parts in a fielded Nike Ajax, the 32-foot-high missile exploded, and that in turn led to the explosion of seven more Nike Ajax missiles.  

On June 7, 1960, at Bomarc Base #1 at McGuire Air Force base in New Jersey, a Bomarc missile (CIM-10) exploded at Launch Shelter 204 after a helium tank in the missile ruptured. The Bomarc that exploded had a W40 nuclear warhead that was a plutonium boosted fission warhead that had a yield of 10 kilotons. 

The warhead did not explode, but much of it melted down as the Bomarc burned in its shelter, spreading parts of the warhead around the area where the fire raged. 

Both these accidents were in the early days of rocket-based air defense systems. These explosions involved little or no collateral damage to the public.

Too close for comfort

Patriot is an old design. Despite multiple updates, its field performance has been relatively unsatisfactory.

Both Saudi Arabia and the UAE have been attacked by ballistic missiles coming from Yemen – most likely operated by Iran, perhaps with North Korean advisers. In a number of cases, Patriots have hit incoming missiles, but almost always when the missiles were very close to their final target, roughly half a mile and at an altitude of 600 to 800 meters.

The Japanese Defense Ministry installed the Patriot PAC-3 antimissile air defense units at its headquarters in Shinjyuku Ward, Tokyo, on January 30, 2016, to defend against possible North Korean long-range missile strikes. Photo: AFP/The Yomiuri Shimbun

Patriot can be used as a point defense system and, in fact, it appears that is its main value. However, experience shows that Patriot has trouble distinguishing a warhead from the missile body from which it detaches. 

The most modern Iranian missiles, including the Yemeni Burkhan H2, separate the warhead from the last rocket stage precisely to make it more difficult to kill the warhead. 

The video and photo evidence reveals that the fragmentation warhead characteristic of Patriot is capable of causing heavy damage to the incoming missile’s last rocket stage, but unfortunately, the warhead still hits the ground relatively near its target if not right on top of it, and explodes.  

A good example is a missile fired at the King Khalid International Airport in Riyadh in Saudi Arabia on November 4, 2017.  The warhead exploded on the outer edge of the airport compound, but within the airport grounds. It missed the terminal building. 

The Burkhan H2 missile “circular error of probability,” or CEP, the likelihood it will hit dead center on a target, is about one mile. China has better missiles. Maybe North Korean missiles are poorer in accuracy – it’s anyone’s guess.

The SM-3 system is much safer than Patriot because it does not use an explosive warhead. Aegis uses a kinetic warhead – hit to kill by disintegrating the incoming missile.

Whether Aegis Ashore is capable of selecting the incoming warhead as opposed to the attacker’s missile body is unclear, but since multiple shots can be fired at a threat that can be quite far away, the chances are better than for the Patriot, because Patriot only reacts when the incoming missile is practically overhead.

China selecting targets

Experts have warned for some time that China was practicing targeting US bases in Japan along with Japanese military bases. Two US Naval officers, Commanders Thomas Shugart and Javier Gonzalez, made this case in 2017. 

Their conclusions were based on simulations and on intelligence. In their presentation, the two naval officers said that commercial satellite imagery of Chinese missile test ranges near the Gobi Desert “show they’ve fired test shots at mock-ups of airfields and life-sized outlines of ships, positioned in the same configuration as the US Navy piers in Yokosuka.” 

They went on to reveal: “Using public data on US bases in Japan to find targets and published Chinese doctrine to prioritize them, they came up with 500 targets: airfields and ports, command posts, communications equipment, fuel tanks and all the other essential infrastructure of military operations. China has enough munitions to destroy all of them.”

In 2018, both Russia and China warned Japan “in stringent terms” not to deploy Aegis Ashore. In 2019, North Korea made similar warnings. The full extent of more recent diplomatic activity by China, Russia and the DPRK is not known, but Japan’s decision to cancel makes it look like its officials were under a lot of pressure.

DF-26 missiles at a 2015 WW II victory parade in Beijing. PHOTO: China Central TV screen grab

Operationally, it is vital to be able to defend air and naval bases from missile strikes. Because of that, Japan previously opted for a viable solution with Aegis Ashore, which was a sensible and important strategic decision. 

Backing away and canceling the Aegis Ashore deal exposes Japanese and American defense installations dangerously. The Japanese decision also raises issues in Washington about Japan’s reliability, especially under crisis conditions.

Would Japan allow the US to take action to militarily block China or North Korea? What about an attack on Taiwan? Would US forces in Japan and on Kadina on Okinawa have a free hand, or would Japan stop them from responding to aggression? 

And even if Japan was not a political obstacle to US action, would China or North Korea be able to knock out US and Japanese land bases?

The Aegis Ashore cancellation is a major setback for regional security and leaves Japanese and US bases exposed to attack.