Two suspected North Korean spy boats recently invaded Japanese territorial waters in the Sea of Japan. A national controversy still rages over the incident, which came at a time when the Diet was debating legislation covering the new Japan-U.S. defense cooperation guidelines. The intrusion sparked a Cabinet order to the Maritime Self-Defense Force to stop and inspect the ships -- the first such order issued under the postwar Constitution. Japanese destroyers fired a number of warning shots and aircraft dropped warning bombs in a vain attempt to try to stop the boats.

Many Japanese say the MSDF should have captured or even sunk the boats. Such notions, common among both older men who went to war for imperialist Japan and young men who have no war experience, are absurd. If the MSDF had sunk the boats, without determining that they were on a mission to harm Japanese interest, Japan would have faced a grave diplomatic crisis. We should be satisfied that the crisis ended after Japanese authorities determined that the ships fled to a North Korean port. It was appallingly reckless of North Korea to send spy boats into Japanese territorial waters at a time when the Diet was discussing legislation for dealing with the kind of emergency that could result from such an intrusion. If it had occurred decades ago, the incident would have stirred speculation about a possible conspiracy by the U.S. Central Intelligence Agency or its South Korean counterpart. Now there is no such talk.

There is no denying that the incident underscored the need for the defense-guidelines legislation and unwittingly encouraged faster Diet action on the bills. Aside from the legislation, the incident raised disturbing questions about Japan's preparedness to deal with surprise invasions by unidentified ships or aircraft into its territorial waters and air space.