Draft on Japan’s Active Cyber Defense System Moves Ahead

The Yomiuri Shimbun

15:04 JST, December 12, 2025

A draft of guidelines on how police and the Self-Defense Forces will implement measures as part of Japan’s active cyber defense to neutralize servers behind a cyberattack was presented at a Liberal Democratic Party meeting on Monday.

Under the draft, serious cases in which “intrusion and neutralization” is considered — such as attacks from overseas servers — would be reviewed in advance by the National Security Council (NSC). The roles of the police and the SDF have also been clarified.

Active cyber defense is meant to strengthen Japan’s cyber response capabilities in three areas: public–private cooperation, monitoring communications data, and intrusion and neutralization. The related legislation is being implemented in stages. With the provisions for the third area scheduled to take effect as early as October of next year, the government is moving ahead with drafting operational guidelines.

According to the draft, the NSC would review such matters as attacks from overseas servers and attacks targeting systems of the SDF or U.S. Forces Japan. Attacks originating from domestic servers will also be subject to review if they affect national security.

In the event of a cyberattack, the NSC will convene a meeting with the prime minister, the chief cabinet secretary, the foreign minister and the defense minister and the minister in charge of cyber security and other relevant people to discuss whether the measures are appropriate. Once approved, the National Police Agency or the SDF would remotely log into the server by exploiting its vulnerabilities and neutralize it such as by deleting attack programs.

Incidents involving overseas servers will be handled either jointly by the police and the SDF or solely by the police. Cases involving the SDF or U.S. Forces Japan will fall under the SDF’s responsibility.

An independent body, the cyber communications information oversight commission, is also planned to be established in April to oversee the system’s operation.