Key Facts
• July 2024: Japan-U.S. ministerial meeting on extended deterrence held in Tokyo.
• December 2024: First “Guidelines on Extended Deterrence” established, detailing nuclear use coordination.
• Multiple tabletop exercises conducted to simulate crisis scenarios in East Asia.
• U.S. set scenarios involving potential nuclear weapon use during these exercises.
• Discussions aimed at ensuring the effectiveness of the U.S. “nuclear umbrella.”
• Japan, as the only nation to experience wartime nuclear attacks, balances nuclear disarmament goals with reliance on U.S. deterrence.
• Rising military activities by China, North Korea, and Russia prompted these discussions.
• December 2024: Delegations visited Japan Ground Self-Defense Force base in Kumamoto City.
Summary
Japan and the United States have deepened discussions on nuclear deterrence, conducting multiple tabletop exercises to simulate crisis scenarios in East Asia. These exercises, part of regular extended deterrence consultations, included scenarios where U.S. nuclear weapons might be used. In December 2024, the two nations established their first “Guidelines on Extended Deterrence,” outlining procedures for intergovernmental coordination during nuclear use and formalizing Japan’s ability to provide input. The discussions aim to ensure the effectiveness of the U.S. “nuclear umbrella” amid increased military activities by China, North Korea, and Russia. While Japan continues to advocate for a nuclear-free world as the only country to have suffered wartime nuclear attacks, its reliance on U.S. nuclear deterrence has grown. The collaboration highlights the evolving security dynamics in the region.
