By Kenta Kamimura / Yomiuri Shimbun Staff WriterShooting down high-altitude North Korean ballistic missiles that fly over Japan en route to Guam could be both technically and legally challenging, according to some observers.
On Thursday, the state-run Korean Central News Agency reported that Pyongyang is considering a plan to simultaneously fire four intermediate- and long- range Hwasong-12 ballistic missiles into waters around the U.S. territory of Guam.
The report prompted Defense Minister Itsunori Onodera to later that day raise the possibility of declaring a “survival-threatening situation.” Such a declaration would enable Japan to exercise its right of collective self-defense, with a view to intercepting North Korean missiles on behalf of the United States.
Conditions difficult to judge
Asked how the government would respond to North Korea’s planned ballistic missile launch during a House of Representatives’ Committee on Security meeting on Thursday, Onodera said, “We’ll be able to respond [to North Korea’s missiles] if the situation threatens Japan’s survival and is judged to meet the three new conditions [for the use of force].”
The security-related laws that took effect in March 2016 stipulate that a “survival-threatening situation” could arise if the United States — an ally of Japan — is subject to an armed attack. Japan would be able to intercept ballistic missiles headed toward the United States if three new conditions permitting the use of force are met. The three conditions were approved by the Cabinet in July 2014 after a new interpretation of the Constitution was adopted.
Recognition of a survival-threatening situation in this case would presuppose a North Korean attack on the United States. “If it is judged that North Korea indicates a clear intention to attack the United States and starts missile launch preparations, an armed attack would be considered to have occurred,” a government official said. That would precipitate the declaration of a survival-threatening situation.
However, a lack of clarity on intent to attack would complicate such a declaration.
North Korea said that it plans for the missiles to fall into waters 30 to 40 kilometers off the U.S. island, beyond its territorial waters.
“If North Korea says it’s targeting the missiles outside [U.S.] territorial waters, it would be difficult to call it an attack against the United States and declare a survival-threatening situation,” a senior Defense Ministry official said.
As a result, Onodera refrained from commenting on the prospective recognition of a declaration, saying, “I’ll refrain from discussing any individual and specific case.”
There are also technical problems in intercepting missiles.
Japan’s missile defense system has two stages of preparedness. The Standard Missile-3 (SM-3) system mounted on Aegis-equipped destroyers represents the first line of defense. The SM-3 interceptors shoot down incoming ballistic missiles in outer space at a maximum altitude of about 500 kilometers. The SM-3 system is designed to shoot down missiles traveling on a parabolic path when they start descending.
If North Korea fires missiles toward Guam, it is highly likely that they would ascend at a high speed when flying over the Sea of Japan, where Aegis-equipped destroyers are deployed. “It’s difficult to intercept [missiles] with the SM-3 system,” a senior Defense Ministry official said.
There are also worries about unexpected events, such as stray ballistic missiles or their fragments falling onto Japan.
Surface-to-air Patriot Advanced Capability-3 (PAC-3) guided missiles represent the second layer of the country’s missile defense system. PAC-3 missiles can destroy targets at altitudes between 10 and 20 kilometers if SM-3 interceptor missiles are not effective.
However, the country’s 34 PAC-3 units attached to 17 anti-aircraft units are mostly deployed in densely populated areas like the Tokyo metropolitan and Kyushu regions as well as at major Self-Defense Forces bases.
A single PAC-3 unit covers an area only several dozen kilometers in radius, leaving many “blank areas” across the country where they have yet to be deployed.
Shimane, Hiroshima and Kochi prefectures, which might fall under the trajectory of North Korea’s missiles, are not covered by the PAC-3 system. At Thursday’s meeting of the Committee on Security, Onodera stressed that the government will strengthen preparedness for those prefectures, saying, “We’ll thoroughly implement various measures.”Speech