Summary On October 16, 2023, a paper authored by Professor Nobumasa Akiyama, Dean of the School of International and Public Policy, entitled 'How Should Japan Consolidate the Credibility of Extended Deterrence?' was published in the AJISS-Commenttary of the Japan Institute of International Affairs. This paper discusses the building of 'deterrence by punishment' capabilities beyond ‘deterrence by denial' as an effort to increase the credibility of Japan's extended deterrence, and the importance of pursuing diplomatic initiatives for threat reduction, in an international context where confidence in extended deterrence has been shaken following Russia's invasion of Ukraine. Professor Akiyama notes that while strengthening the extended deterrence arrangement with the US is essential for Japan's security, what is required now is an action plan the US and Japan, in cooperation with other partner countries, can swiftly implement to build assets comprising deterrence architecture, a coordination mechanism for the US-Japan alliance to effectively operate assets optimized for the threat landscape and a solid political foundation. He also stated that it is essential for the United States, Japan, and other partner countries to send a closely coordinated and unified signal to China and North Korea to avoid increasing room for coercive action by China at the regional level in East Asia, while at the same time making diplomatic efforts through strategic dialogue with China and North Korea to ensure crisis stability and build confidence leading to future arms control.