After two missile flyovers, Japan is sick and tired of North Korea’s nonsense. On Tuesday, September 19, Japan moved a Patriot Advanced Capability-3 missile defense unit (PAC-3) to the Hakodate base on the island of Hokkaido. The PAC-3 was moved from its previous location in Yakumo in response to North Korea’s most recent missile test, which flew over southern Hokkaido. The PAC-3 system now placed near the flight path of that test.
Two-Step Defense
Japan’s current missile defense structure is a two-step process. If the island nation were to respond to such an attack, Standard Missile-3 (SM-3) interceptors would shoot down the missiles mid-flight. The SM-3 interceptor is a ship-borne missile used to intercept short and mid-range ballistic missiles. Produced by Raytheon, it is a part of the Aegis Ballistic Missile Defense System and used on guided missile destroyers.
The Japanese Maritime Self-Defense Force currently fields six ships with the Aegis system. There are two Atago-class destroyers, the JDS Atago and the JDS Ashigara, as well as four Kongō-class destroyers, the JDS Kongō, JDS Kirishima, JDS Myōkō, and the JDS Chōkai.
The second step is the PAC-3 system. Should the destroyer-based missile systems fail, the PAC-3 system would engage the target. This surface-to-air missile system has a range of 20 kilometers and a flight altitude of over 79,000 feet. With speeds of Mach 4.1, it’s a capable interceptor.
PAC-3’s on the move
Japan currently has 34 PAC-3 units. Most of these systems are used to defend the capital and surrounding regions. However, four of them were relocated to southwestern Japan after North Korea threatened the U.S. territory of Guam.
Japanese Defense Minister Itsunori Onodera said that the Hakodate move was “a precaution” against another possible emergency. Emergency has been the term Japan used for the past two missile fly-overs. Japan has significant constitutional limits on the use of force and can only act in self-defense. Although Minister Odonera has previously said that a 2015 security law would potentially allow Japan to shoot down missiles heading for Guam, the Japanese Constitution otherwise limits their engagements to those that threaten Japan proper.
Debate over Pre-emptive strikes
North Korea’s consistent provocations have led many in the Japanese government to reconsider the limits of their constitution and their options in dealing with the rogue state. A 1956 ruling determined that pre-emptive strikes fell within the right of self-defense, but many within Japan are not so sure.
A significant item of debate within Prime Minister Shinzo Abe’s government is the acquisition of cruise missiles. While cruise missiles, like the Tomahawk, Japan would be able to strike at a North Korean launch site if they detected an imminent threat of attack. While this ability is a major boon to Japan’s overall national security, the policy established since reconstruction after World War II has been to avoid offensive weapons.
Japan is taking legitimate steps to further its ability to defend itself, but constitutional limitations and public opinion may hamstring its efforts. Further North Korean aggression may push their government towards further reform, especially in the face of our unique alliance.
