Japan and Nuclear Weapons: Between Extended Deterrence and Normative Dilemmas
Since the late 1950s, Japan’s nuclear weapons policy has been based on the coexistence of two competing normative rationales: the rejection of nuclear weapons, rooted in the legacy of Hiroshima and Nagasaki, and the recognition of the central role of US extended nuclear deterrence for Japan’s security.
The deterioration of the security environment in Northeast Asia is undermining the balance between these two approaches. Faced with the unprecedented expansion of China’s nuclear arsenal, North Korea’s consolidation as a regional nuclear power, and the resurgence of the Russian threat, Japan is confronting growing risks that are testing the credibility of extended deterrence—concerns that have intensified since Donald Trump’s return to power.
In this context, despite persistent calls for domestic nuclear proliferation, the rejection of a military nuclear program stems from a deliberate choice, reaffirmed since the 1960s, based on constraints that remain valid to this day. At the same time, the public debate on nuclear issues is broadening to focus on three questions that heighten the tension between the two normative approaches: the revision of the principle of not introducing nuclear weapons onto national territory; nuclear sharing with the US, which is officially rejected but is attracting growing interest; and naval nuclear propulsion, whose strategic value faces legal and political obstacles.
These debates indicate that the future of Japan’s nuclear weapons policy is increasingly shaped by the regional strategic environment and is now playing out in the tension between the strict commitment to the three non-nuclear principles and the reality of deterrence imperatives.
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Japan and Nuclear Weapons: Between Extended Deterrence and Normative Dilemmas
Center for Asian Studies
Asia is a nerve center for multiple global economic, political and security challenges. The Center for Asian Studies provides documented expertise and a platform for discussion on Asian issues to accompany decision makers and explain and contextualize developments in the region for the sake of a larger public dialogue.
The Center's research is organized along two major axes: relations between Asia's major powers and the rest of the world; and internal economic and social dynamics of Asian countries. The Center's research focuses primarily on China, Japan, India, Taiwan and the Indo-Pacific, but also covers Southeast Asia, the Korean peninsula and the Pacific Islands.
The Centre for Asian Studies maintains close institutional links with counterpart research institutes in Europe and Asia, and its researchers regularly carry out fieldwork in the region.
The Center organizes closed-door roundtables, expert-level seminars and a number of public events, including an Annual Conference, that welcome experts from Asia, Europe and the United States. The work of Center’s researchers, as well as that of their partners, is regularly published in the Center’s electronic journal Asie.Visions.
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