Japan's ruling Liberal Democratic Party (LDP) and its coalition partner, the Japan Innovation Party (JIP), plan to begin working-level consultations in November 2026 on revising the country's three key security documents by year's end, with nuclear-powered submarines and a potential review of the country's Three Non-Nuclear Principles expected to dominate talks, according to reports citing multiple sources familiar with the matter.

Key Proposals on the Table

The LDP has called for an early feasibility study into possessing submarines capable of launching long-range missiles, including vessels that use 'next-generation propulsion' systems. The JIP has gone further, arguing explicitly that nuclear power is the only viable propulsion option for such submarines and calling for their introduction 'as soon as possible.'

Beyond submarine propulsion, the JIP has also urged a review of the principle that prohibits the introduction of nuclear weapons into Japan — one of the country's three longstanding Three Non-Nuclear Principles — calling for a reassessment to 'reflect current realities.'

What the Government Has Said

Japanese Prime Minister Sanae Takaichi recently acknowledged there was 'room for further discussion' on the specific wording of the Three Non-Nuclear Principles. Defence Minister Shinjiro Koizumi has repeatedly called for discussions on nuclear weapons and related security policies 'without taboos,' signalling a broader shift in the administration's posture.

The two coalition parties are expected to coordinate their positions through working-level consultations before any formal revision is finalised. This approach mirrors the LDP's earlier playbook: when Japan formulated its current three key security documents in 2022, the acquisition of counterstrike capabilities triggered multiple rounds of consultations between the LDP and its then-coalition partner, Komeito, before an agreement was reached.

Opposition and Public Concern

The administration's moves have drawn pushback from within Japanese civil society. On Monday, 20 October 2026, Japanese nuclear experts and peace advocates held a symposium in Tokyo to oppose the introduction of nuclear-powered submarines, warning that such a step could undermine regional security and the international nuclear non-proliferation regime. The administration's moves on nuclear-related security policy have, according to reports, raised concerns across various sectors of Japanese society.

Why This Revision Matters

Japan's Three Non-Nuclear Principles — not possessing, not producing, and not permitting the introduction of nuclear weapons — have been a cornerstone of the country's postwar security identity since the 1960s. Any revision would represent a historic departure from decades of policy, with significant implications for the security architecture of the Indo-Pacific region and for Japan's relationships with neighbours including China and South Korea. This comes amid a broader regional trend of military capability expansion, with North Korea's nuclear advancements and China's assertiveness frequently cited by Japanese officials as justifications.

The outcome of the November consultations is expected to set the direction for Japan's security posture well into the next decade.