The U.S. Department of Homeland Security (DHS) and the Government of Japan conducted a tabletop exercise from August 21-22 to enhance maritime cybersecurity and incident response capabilities. The exercise simulated a significant cyber incident at a Japanese port, testing response policies and fostering discussions on improving mutual preparedness for threats to interconnected critical infrastructure.

This collaboration aligns with Secretary Mayorkas’s priority to strengthen cooperation with Indo-Pacific partners, focusing on incident response protocols, information sharing, and future bilateral efforts to mitigate cyber threats to maritime infrastructure. The exercise also provided an opportunity for DHS and Japan's Ministry of Land, Infrastructure, Transport and Tourism to engage on relevant maritime cybersecurity policies, including President Biden's February 2024 Executive Order.

"Exercises like these bolster our nation’s capabilities and establish reliable channels for coordination with key international partners,” said Under Secretary for Policy Robert Silvers. “Cyber attacks pose a shared risk, beyond any single nation’s control, making it imperative for the United States and Japan to collaborate in addressing these challenges to thrive in such interconnected environments.”

Admiral Linda Fagan, Commandant of the U.S. Coast Guard, emphasized the importance of this collaboration: “Malicious cyber actors recognize ports worldwide possess the same critical vulnerabilities and are increasingly willing to target them. Coordinating together to share risk information, improving operational coordination between incident responders, and building our collective capacity to withstand the targeting of port infrastructure is a necessary step to safeguard the global maritime system."

Dr. Masahiro Inada, Director General of the Ports and Harbours Bureau at Japan's Ministry of Land, Infrastructure, Transport and Tourism added: “Cyber attacks to ports and harbors could potentially disrupt key international logistics functions which serve as a lifeline of Japan... I intend to share best practices gained through this exercise and continue to promote the reinforcement of cyber security of ports and harbors.”

CISA’s Executive Assistant Director for Infrastructure Security Dr. David Mussington remarked on the significance of international planning: “This joint exercise underscores the importance of international planning to ensure we are equipped to respond to cyber threats and reduce risks to global maritime activities.”

This was DHS's second maritime security tabletop exercise this year following a similar event with Indonesian counterparts in June 2024. The two-day event was organized by various DHS offices including CISA and the U.S. Coast Guard, with participation from U.S. Embassy in Tokyo officials among others. On the Japanese side, participants included several governmental agencies such as NISC, Prefectural Police, Port Authorities, National Security Secretariat, Japan Coast Guard, National Police Agency.