North Korea has become Japan’s main security concern in the post-Cold War era, as underscored by Pyongyang’s July 5 test-firing of seven ballistic missiles into the Sea of Japan.
The launches put the spotlight on Japan’s plans for an elaborate antiballistic missile system, raising a key security question: Will the system, estimated to cost 1 trillion yen, actually work?
Japan plans to create a two-layer missile defense, composed of two types of intercepter missiles developed by the United States — the Aegis destroyer-armed Standard Missile-3, designed to hit missiles in space, and ground-based Patriot Advanced Capability-3 missiles, which have a 20-km range and are for hitting missiles descending in the atmosphere toward their target, assuming they got past the SM-3s.
Under the plan, four Maritime Self-Defense Force Aegis destroyers will be armed with SM-3s between fiscal 2007 and 2010.
The ground-based PAC-3s will be deployed to 16 units between now and fiscal 2010 at Air Self-Defense Force bases in Iruma, Saitama Prefecture; Hamanatsu, Shizuoka Prefecture, the city of Gifu and at another undecided location. The cost of the entire missile defense system is estimated at 1 trillion yen.
Although the government plans to deploy the systems, many experts question their effectiveness, and even advocates agree the government has not disclosed enough information about the interceptors’ accuracy and say it is too soon to know if they will work.
“The system is still under development, and many experiments are ongoing,” said Tomohiko Tada, a defense technology analyst well-versed in missile defenses.
“It’s a combination of various systems still being developed. You cannot say anything (about effectiveness) right now,” Tada said.
Developing an effective defense against ballistic missiles is considered difficult, if not impossible.
An intermediate range ballistic missile fired from North Korea could reach Japan in less than 10 minutes, speeding toward its target at Mach 8.8 or higher.
According to the Defense Agency, in terms of relative speed, shooting down a ballistic missile with an interceptor is more difficult than hitting a bullet fired from a rifle with another bullet.
The Defense Agency has refused to provide information on the system’s accuracy and other key details, citing the need to keep its capabilities secret from potential enemies.
The SM-3 is designed to knock out ballistic missiles at an altitude of more than than 200 km, during the “midphase” of flight.
The Defense Agency said two Aegis destroyers deployed to the Sea of Japan could provide protection from North Korean ballistic missiles for most of Japan.
The PAC-3 is meant to destroy missiles that get past the SM-3s, intercepting them during their “terminal phase.”
The Pentagon has conducted nine SM-3 tests, claiming they succeeded in destroying their targets eight times. Many experts, however, are skeptical.
“The key question remaining, however, centers around levels of effectiveness, particularly in wartime. Under test-range conditions, most military systems perform better than they do in an operational environment,” said a 2005 report by the Congressional Research Service of the U.S. Library of Congress.
Hiromichi Umebayashi, president of the Yokohama-based nonprofit peace research group Peace Depot, also claimed that decoys, or chaff — metal strips or foil released to confuse enemy radar — can fool interceptor missiles relatively easily.
“I think the argument that the system won’t work in practical (terms) is prevailing,” Umebayashi said.
He also said the missile defense system will only escalate an arms race between countries that possess ballistic missiles and those trying to build ABM systems.
Defense Agency officials nonetheless say North Korean ballistic missiles are a serious threat and the U.S.-developed system is the only means now available to defend against them, should the U.S. deterrence fail.
According to a 2006 paper by Gen. Burwell Bell, commander of U.S. forces in South Korea, North Korea has 200 Rodong missiles with a range of 1,300 km, putting most of Japan within their range.
“Conditions in a real war are different from those in tests. You cannot say (Japan) will be 100 percent safe” by building the missile defense system, Defense Agency chief Fukushiro Nukaga told reporters at the Japan National Press Club on July 21.
Thus, while building up the defenses, Japan should ensure its military alliance with the U.S. is strong enough to deter North Korea, Nukaga said.