Why does Japan choose to remain naked to the threat of North Korean missiles?

North Korean leader Kim Jong Il, fearing that he is next on U.S. President George W. Bush's list for "regime change," is openly threatening Japan with his Nodong missiles. Yet Japan chooses to remain naked to this threat. Why doesn't it ask for PAC-3 (Patriot) missiles to be deployed by U.S. forces in Japan?

In the prelude to the Iraq war, PAC-3s were sent to Israel, Kuwait and Turkey to protect Iraq's neighbors from its Scud missiles. These have apparently performed quite well. Although PAC-3s would not nullify the Nodong threat to Japan, they would provide some protection for key installations such as airfields and ports.

Japan should also be drawing attention to the fact that an attack on any of the major U.S. bases in Japan would also constitute an attack on the United Nations. That's because those bases also fly the U.N. flag. Few in Japan or elsewhere seem to know that Camp Zama (40 km southwest of Tokyo) is the rear headquarters of the U.N. Command in South Korea.