The Defense Agency's plan to build a missile-defense system is causing much controversy here. The basic question is whether such a system is urgently needed and whether it is suitable for ensuring the peace and security of Japan. The question should be addressed very carefully from various angles. The agency is seeking related funding for fiscal 2004.

On the face of it, the plan looks premature since the current Japan-U.S. technological research project has yet to produce a conclusion. The agency's plan is said to differ from this project, yet the government does not seem to have fully discussed whether to introduce an antimissile system. So why the rush to build it? The plausible answer is that the plan stems from the U.S. decision to start deploying its own missile network in 2004; in other words, Japan appears to be going along with the United States under the bilateral security alliance.

According to the Defense Agency plan, a ballistic missile fired against Japan would be first detected by sensors and then destroyed in space by a missile launched by an Aegis-equipped destroyer. If that first-stage defense failed, a ground-to-air Patriot guided missile would be launched to shoot down the incoming missile before it hit a target.