The Shield Makes the Sword Usable

In response to North Korea's nuclear tests, Japan has been urged to totally revamp their missile defense system. MP Gen Nakatani, who is a former defense minister and the ruling head of the Liberal Democratic Party, has been a vocal supporter of the shift:

"We have no choice but to consider switching from the existing passive missile defence to an active missile defence, where launch targets on enemy ground can be directly attacked."

As of right now, Japan has two different layers to its missile defense program, which has been active since the Strategic Defense Initiative ("Star Wars") under Ronald Reagan. The Japanese currently operate the PAC-3 surface-to-air missile system for terminal phase defense and the Aegis Ballistic Missile Defense system for sea based mid-course phase defense. Both these systems have been extensively tested by the Japanese military, although the success rates vary widely depending on who you listen to. That being said, the systems have not been extensively tested by the Japanese in a combat scenario, so it's really anyone's guess as to how they would perform if a North Korean IRBM was headed towards Tokyo.

On a strategic level, what does all of this really mean? Japan's politicians are doing what one would expect, talking up a missile defense system in order to give a sense of security to the people. Going back to a previous post, would an enhanced (and effective) Japanese BMD system foretell the acquisition of nuclear weapons? Does the shield make the sword usable? And what to make of Nakatani's comments?

I think boost-phase missile defense is probably a bad idea for Japan to employ against North Korea. For one thing, that technology is highly risky and even war provoking on some level (especially against the belligerant DPRK government). The Boeing YAL-1 is one of the few developed boost phase missile defense systems, but that has been targeted by Sec. Gates for discontinued production. In addition, boost phase defense only leaves you about 2-3 minutes to take our your target, so planning has to be extremely accurate.

In the end, instead of building an "offensive" missile defense system, Japan should take the initiative with China, Russia, South Korea, and the United States to deal with the North Korea issue. The condemnation by Beijing and Moscow cannot be underlooked, this has huge strategic importance, because with their presence, North Korea has nobody else to turn to. Overreaction is a much worse strategy than underreaction in this instance.