Report

Securing the future of US-Japan-South Korea cooperation

This report from UK think tank Chatham House examines how to strengthen the trilateral partnership and maintain stability in the Indo-Pacific.

In August 2023, US president Joe Biden, Japanese prime minister Fumio Kishida and South Korean president Yoon Suk Yeol agreed a bold strategic vision for the development of trilateral cooperation between their countries. However, the structural and personal factors that led to that bold vision are now in doubt. Changes of leadership in all three countries since 2023 may mean a lack of personal and political will at the top level.

This paper argues that while trilateral cooperation is likely to persist, officials and policymakers in all three countries will need to keep the momentum going without much in the way of support from the very top, as the Trump administration’s new national security strategy perhaps shows. If they are to succeed, policymakers in Seoul, Tokyo and Washington must rethink the role of ‘values’ such as democracy promotion as coalescing factors in their partnership. Instead, their focus must shift to demonstrating tangible benefits from cooperation by securing mutual interests such as freedom of navigation, increasing burden-sharing in regional defence and security, and deepening collaboration on economic security and technology.