This week’s overflight of Japan by a North Korean missile was a major escalation of Pyongyang’s missile strategy. Although not unprecedented, the overflight of the northern island of Hokkaido was a clear sign that North Korea did not expect Tokyo to actually do anything in response. If Japan wanted to mount a more muscular response, what options would it have?
Japan is an avowedly pacifist country, with a military—actually a Self Defense Force—that is generally incapable of taking action against North Korea. The Self Defense Forces have little to no offensive weapons and rarely if ever train in offensive operations. Still, the country does have options, from actually utilizing its robust ballistic missile defenses to developing an offensive strike capability.
The first response Japan could mount is to attempt to shoot down the next missile that overflies the country. Japan’s ballistic missile defenses (BMD) is second only to that of the United States in capability, and the country has six Aegis destroyers with SM-3 ballistic missile interceptors. Theoretically, two of these destroyers could mount a defense of Japan that could shoot down the next medium or intermediate-range ballistic missile that overflies Japan.
Japan’s ship-based BMD capability has always been more notional than operational, and the Maritime Self Defense Force (MSDF) would have to adjust to the concept of constantly having enough destroyers to respond to a BMD launch event. These destroyers would have to be in position and their crews at a high state of readiness to intercept a North Korean missile. This need not be a 24/7 requirement: there is some evidence the United States knew the latest missile test was set to occur days before it actually did, theoretically giving the MSDF the time to scramble destroyers from Yokosuka.
A longer term option is that Japan purchase or develop a weapon to destroy North Korean missiles on the launch pad. The government of Prime Minister Shinzo Abe has hinted—and coyly denied— it would like to purchase Tomahawk cruise missiles for this purpose, and Abe’s argument will only be bolstered by this latest overflight incident. Japan is close enough that these missiles could be based on land, although embarking them on the country’s excellent Soryu-class diesel electric attack submarines is another possible deployment strategy. Japan could also develop its own missile system, perhaps using ramjet technology from the new ramjet-powered XASM-3 anti-ship missile .
As a pacifist country, there are obvious problems with Japan procuring cruise missiles. That having been said, the country was able to justify its creation of an amphibious brigade—previously considered an offensive weapon of war—on the grounds it could be used to reinforce or take back Japanese territory. Cruise missiles, Tokyo might argue, could be used to pre-emptively strike North Korean missiles in a crisis when a launch is imminent.
A naval show of force in the Sea of Japan (East Sea) is another option. Japan has one of the largest surface force fleets in the world, with nearly fifty destroyers, and deploying them off the coast of North Korea would send a powerful message. Although these ships do not carry surface-to-surface missiles, they could certainly carry Tomahawk land attack cruise missiles in the future.
Mounting a show of force is less dangerous than it sounds, but not completely without risk. Despite North Korea’s large armed forces there are few weapons that could actually hit a Japanese naval task force, let alone find it. The only possible exception are North Korea’s copies of the Kh-35 anti-ship cruise missile, known to the Pentagon as the KN-01 . Even then, Japanese anti-ship missile defenses are some of the best in the world, and are almost certainly up to the task of identifying and destroying incoming an ASCM threat.
Yet another option is scheduling regular, annual exercises with the United States designed to support a Korean war contingency. North Korean leader Kim Jong-un is well known to loathe the annual Ulchi Freedom Guardian wargames . A U.S.-Japan exercise designed to complement Ulchi Freedom Guardian could spark similar North Korean resentment.
The U.S.-Japan exercise could simulate, for example, the evacuation of American nationals and casualties from the Korean peninsula to Japan, the deployment of U.S. naval power from Japan and Okinawa to the Sea of Japan, the beefing up of security at military bases in Japan and even coordination with South Korean forces. The exercises could become a bargaining chip for Japan against North Korea, forcing it to give up something in order to halt the exercises.
Japan’s deep pacifist streak is an example to all nations. That having been said, being pacifist doesn’t mean accepting bullying, or being unable handle unprovoked threats to security. The problem with provocations of the North Korean kind is that they must continue to escalate or they will lose their power to provoke. If Japan’s government does not respond forcefully to missile overflights of its country, it should strongly consider what North Korea’s next step will be.