Managing First-Strike Pressures, the Nuclear Taboo, and Proliferation Risks in Northeast Asia

A Joint Research and Policy Dialogue Project

Toda Peace Institute & Asia-Pacific Leadership Network (APLN)

Northeast Asia faces a convergence of nuclear escalation and proliferation risks more acute and interconnected than at any point since the end of the Cold War. China is undertaking a significant expansion of its nuclear arsenal, and its commitment to No First Use is coming under question. North Korea has codified a first-use doctrine and unveiled its first SSBN in late 2025. Arms control frameworks are eroding, with New START having expired in February 2026 without a replacement. The credibility of US extended deterrence is under unprecedented strain, with growing proliferation pressures in both Japan and South Korea. These challenges are closely interconnected, yet they are rarely analysed together. This joint project brings them into a single, integrated framework, building on prior research by both organisations, including APLN’s Asia-Pacific Strategic Risks project and TPI’s Research Clusters on Cooperative Security, Arms Control and Disarmament, and Reassurance in Northeast Asia.

The project brings these threads together and extends them into the domains of (1) first-strike pressures, and No First Use policy; (2) reinforcing the nuclear taboo; and (3) regional threat perceptions and the risk of proliferation. It asks: given what we now know about regional threat perceptions and the limits of deterrence, what concrete policy measures can address first-strike pressures, reinforce the norm of non-use of nuclear weapons, and reduce the risk of nuclear proliferation in Northeast Asia?

The project will combine commissioned research papers with a workshop and policy dialogue taking place in Tokyo, 21-24 September 2026 among experts in Japan, South Korea, China, the United States and Russia.