Nuclear-weapon endorser

Did not participate in TPNW negotiations

Has not yet joined TPNW

Japan has not yet signed or ratified the Treaty on the Prohibition of Nuclear Weapons. It did not formally participate in the negotiation of the treaty at the United Nations in New York in 2017 and thus did not vote on its adoption.

Japan supports the retention and potential use of US nuclear weapons on its behalf, as indicated in various policy statements, including the country’s national security strategy of 2013, which states that “the extended deterrence of the US, with nuclear deterrence at its core, is indispensable [to Japan]”.

A public opinion poll conducted by Japan’s national broadcaster, NHK, in December 2019 found that 66 per cent of Japanese people believe that their government should join the treaty, with 17 per cent opposed to joining and the remainder undecided.

In February 2017, a month before the commencement of treaty negotiations at the United Nations, the US president, Donald Trump, and Japanese prime minister, Abe Shinzō, issued a joint statement declaring that “[t]he US commitment to defend Japan through the full range of US military capabilities, both nuclear and conventional, is unwavering”.

The Japanese government has indicated that it does not intend to sign or ratify the treaty, despite significant public pressure on it to do so. 

The government’s unwillingness to date to support the treaty has angered many of the remaining survivors of the 1945 atomic bombings of Hiroshima and Nagasaki, known as hibakusha, who have said that they feel betrayed by Japan’s official stance.

Many Japanese cities, including Hiroshima and Nagasaki, have called on the Japanese government to sign and ratify the treaty.

The mayor of Nagasaki, Tomihisa Taue, said in August 2017, at a ceremony to mark the atomic bombing of his city, that the adoption of the treaty a month earlier “was a moment when all the efforts of the hibakusha over the years finally took shape”.

In August 2019, on the anniversary of the atomic bombing of Hiroshima, the mayor of that city, Kazumi Matsui, called on “the government of the only country to experience a nuclear weapon in war to accede to the hibakusha’s request that the [treaty] be signed and ratified”.

The former Japanese prime minister Hatoyama Yukio, former foreign minister Tanaka Makiko, and former defence minister Tanaka Naoki were among the signatories to an open letter in September 2020 calling on current leaders to “show courage and boldness – and join the treaty”.

Japan voted against a UN General Assembly resolution in 2019 that welcomed the adoption of the treaty and called upon “all states that have not yet done so to sign, ratify, accept, approve, or accede to the treaty at the earliest possible date”.

However, Japan attended the opening session of the conference and delivered a statement explaining its decision not to participate. It said that “it would be difficult for Japan to participate in this conference in a constructive manner and in good faith”.

In 2016, Japan voted against the UN General Assembly resolution that established the formal mandate for states to commence the negotiations in 2017 on “a legally binding instrument to prohibit nuclear weapons, leading towards their total elimination”.

Many media outlets and civil society groups in Japan criticised the government’s decision to oppose the negotiations. The Japan Times, for example, argued that the decision “contradicts the nation’s long-standing call for the elimination of [nuclear] weapons as the sole country to have suffered nuclear attacks”.

The atomic bombs detonated over Hiroshima and Nagasaki in the final days of World War II killed more than 200,000 people instantly or within a few months of the attacks. Many thousands more died in the years following the attacks from illnesses caused by their exposure to radiation from the bombs. Almost all of the victims were civilians.

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ICAN Parliamentary Pledge

These are the elected representatives in this country that support and promote the TPNW:

Shinji Morimoto

Satoshi Inoue

Ayaka Shiomura, Member of House of Councilors


ICAN Cities Appeal

These are the cities and towns in this country speaking out in support of the TPNW:

See also the Mayors for Peace appeal on the TPNW

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