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.
Available in:
Themes and regions
ISBN / ISSN
Share
This page contains only a summary of our work. If you would like to have access to all the information from our research on the subject, you can download the full version in PDF format.
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.
The Oceania Factor in France’s Evolving Indo-Pacific Strategy
This paper examines the two-way relationship between France’s Indo-Pacific strategy and developments in Oceania. Oceania was not a priority in the initial years of France’s Indo-Pacific strategy, as the region was largely treated as secondary to major strategic hotspots and key partnerships, while overseas territories were primarily handled as domestic issues and recipients of a top-down strategy.
France’s View: From Diplomacy to Public-Private Action
France has emerged as the EU’s IMEC forerunner, combining port infrastructure, diplomatic alliances and public-private cooperation. With Marseille Fos at its core, the country brings a strategic hub for logistics, energy and digital connectivity to the corridor.
Trump II, the Crisis of the Rules-Based Order and Europe’s Indo-Pacific Strategy
This article examines the implications of Trump II for Europe’s engagement in the Indo-Pacific. The piece contends that Trump II is accelerating the erosion of the rules-based order and undermining the relevance of the Free and Open Indo-Pacific (FOIP) concept, while forcing Europe to refocus on its own continental security amid US retrenchment. Paradoxically, these very constraints create conditions for a more autonomous, pragmatic, and explicitly interest-driven European engagement in the Indo-Pacific, rather than outright withdrawal.
China and Trade in Critical Raw Materials (CRMs)
Critical raw materials (CRMs) have become central features of a new dynamic in global power politics, with China now wielding considerable leverage. Amid rising regional and global uncertainty, resource security is back in the spotlight as a key determinant of sovereignty and national security for Europe, its allies and its partners. The very survival of key, even vital industries, from automotive to aerospace to health to energy to defense, is at stake.