The Indo-Pacific geostrategic environment is rapidly evolving, including a shifting US regional posture, a rapid Chinese nuclear build-up, growing tensions in the Taiwan Straits, a deepening Russia-North Korea military partnership, rising defence spending, and rapid advances in military technologies. What do these developments mean for the future of nuclear weapons in the Indo-Pacific?
Drawing on consultations with more than thirty nuclear weapons and Indo-Pacific security experts from Australia, Japan, South Korea, and the United States, this resource outlines the key forces driving and restraining six regional nuclear proliferation scenarios. It offers a useful introduction to regional proliferation dynamics for those looking to build their knowledge in this area.
Causal pathways
Credible causal pathways that could lead to the People’s Republic of China (PRC) achieving a secure, second-strike capability vis-à-vis the US homeland by 2035.
Credible causal pathways that could lead to the Democratic People’s Republic of Korea (DPRK; North Korea) achieving a secure, second-strike capability vis-à-vis the US homeland by 2035.
Credible causal pathways that could lead to Japan possessing at least one functional nuclear weapon under independent command and control by 2035.
Credible causal pathways that could lead to South Korea possessing at least one functional nuclear weapon under independent command and control by 2035.
Credible causal pathways that could lead to the Democratic People’s Republic of Korea (DPRK; North Korea) no longer possessing nuclear weapons by 2035.
Credible causal pathways that could lead to the United States and the PRC engaging in direct military conflict involving the offensive use of at least one nuclear weapon (by either side) by 2035.
These proliferation pathways were developed by nuclear weapons and Indo-Pacific security experts from Australia, Japan, South Korea, and the United States at a tabletop exercise (TTX) held in Sydney in March 2026. They have been edited for length and clarity and reflect the authors’ interpretations of the discussions; they do not necessarily reflect the views of the TTX participants.
The authors coded the likelihood of occurrence and wrote the contextual information for each step in the proliferation pathway. In doing so, they drew on the TTX discussions as well as virtual focus groups with Australian, Japanese, South Korean, and US experts held in February 2026.
The authors thank the more than thirty experts who participated. These pathways are notional and are not intended as a comprehensive account of the factors driving and restraining nuclear proliferation in the Indo-Pacific. Any errors are the authors’ own.