Eighty-one years after the atomic bombings of Hiroshima on August 6, 1945, and Nagasaki on August 9, Japan is confronting a profound contradiction: how to maintain its identity as the only nation to have suffered wartime atomic attacks while simultaneously bolstering deterrence against a growing number of nuclear-armed adversaries.
This dilemma became particularly apparent during recent commemorations. Prime Minister Takaichi Sanae affirmed that Japan "maintains" its Three Non-Nuclear Principles and its commitment to a world free of nuclear weapons. However, when questioned about the explicit affirmation of these principles in three key strategic documents slated for revision by year's end, Takaichi declined to predetermine the exact wording, introducing a notable ambiguity.
Japan's Three Non-Nuclear Principles, established by former Prime Minister Sato Eisaku in 1967, prohibit the possession, production, and introduction of nuclear weapons into Japanese territory. These principles have long been a cornerstone of Japan's postwar identity.
The strategic landscape has significantly shifted since the principles' inception. China is rapidly modernizing and expanding its nuclear arsenal, North Korea continues its nuclear weapons development, and Russia remains a major nuclear power with deepening ties to both Beijing and Pyongyang. Concurrently, concerns about the reliability of the U.S. extended nuclear deterrence have intensified. Analysts suggest that adversaries now possess more credible means to strike the U.S. homeland, raising questions about whether Washington would risk retaliation to defend allies like Japan or South Korea, especially under an "America First" policy.
Within Japan, the reluctance to openly discuss nuclear deterrence is diminishing. Defense Minister Koizumi Shinjiro has stated that nuclear issues can no longer be sidestepped in policy discussions. Former Joint Staff Chief Kawano Katsutoshi has also questioned the indefinite assumption of the U.S. nuclear umbrella's strength, advocating for a broader national debate.
Prime Minister Takaichi herself previously voiced concerns about the wording in the National Security Strategy regarding the Three Non-Nuclear Principles. In a 2024 book, she revealed that, as a Cabinet minister in 2022, she had objected to language stating that Japan’s basic policy of adhering to the Three Non-Nuclear Principles would remain unchanged. She ultimately approved the Cabinet decision reluctantly after her request for removal was denied.
This history lends weight to her carefully chosen words during recent commemorations. The tension could become more tangible in the early 2030s with the U.S. Navy's development of a nuclear-armed Sea-Launched Cruise Missile (SLCM-N) for integration onto Virginia-class attack submarines. Japan will face the question of whether strict adherence to the "not permitting the introduction" principle is compatible with port visits by U.S. vessels potentially carrying such weapons, particularly given Washington's policy of neither confirming nor denying their presence.
This dilemma already affects Japan's defense diplomacy. For example, France’s nuclear-powered aircraft carrier, the Charles de Gaulle, has notably avoided Japanese ports, visiting other Indo-Pacific nations like Indonesia, the Philippines, and Singapore during Operation Clemenceau 25, its 2024-2025 Indo-Pacific deployment. While its Rafale M fighters can carry France's nuclear-armed ASMP-A missile, Paris, like Washington, does not confirm or deny the presence of nuclear weapons on its strategic platforms. Rear Admiral Guillaume Pinget, former commander of the French Pacific Command, stated that France respects Japan's laws but indicated that a future visit would depend on an invitation.
Abandoning the Three Non-Nuclear Principles hastily would incur significant political and diplomatic costs, given their strong association with Hiroshima and Nagasaki and Japan's role in advocating global nuclear disarmament. However, treating the principles as immutable in the face of evolving strategic realities risks creating a disconnect between declared policy and the deterrence architecture being built by allies.
For Japan, the choice is not simply between nuclear armament or pacifism. The more immediate challenge lies in whether the principle of "not permitting the introduction" of nuclear weapons can endure while Japan simultaneously seeks to strengthen its reliance on U.S. extended nuclear deterrence. Eighty-one years after the atomic bombings, the decision to avoid this question is, in itself, becoming a strategic choice.
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Put more starkly, the question is this: Would an American president risk Los Angeles to defend Tokyo or Seoul?
