The Japanese public now favours discussion on nuclear sharing. In multiple opinion  surveys conducted after the Russian invasion of Ukraine, around 70 to 80% of respondents said they supported discussing whether Japan should consider a nuclear sharing agreement with the U.S. Nuclear sharing is an agreement that would allow Japan to use American nuclear weapons on its soil and operate them jointly upon an order from the U.S. It is based on the NATO model of nuclear sharing used during the Cold War, when NATO countries in Europe, overpowered by the Warsaw Pact countries, formed the nuclear sharing framework to deter invasion. A populace open to discussing a nuclear sharing policy is a new phenomenon, considering that Japanese public opinion had been staunchly anti-nuclear since World War II.

Despite the shift in public opinion, a nuclear sharing agreement is far from becoming a reality. The government is nowhere near accepting of the idea because it goes against Japan’s position forbidding nuclear weapons on its soil. “It is unacceptable from the standpoint of adhering to the three non-nuclear principles,” stated current Prime Minister Kishida, though adding that he isn’t opposed to internal discussions within parties. It’s safe to say that Japan won’t be signing an agreement that strays away from the official government stance, nevertheless, it is worthwhile to analyze what created such a big shift in public opinion in a country with an anti-nuclear sentiment. 

Why It’s Odd for Japan to be Talking About Nuclear Sharing 

Japan’s sudden shift in public opinion is odd considering its historic commitment to non-proliferation. Non-proliferation is the effort to prevent the spread of nuclear weapons, a position Japan has taken as the only country to have suffered the effect of atomic bombs during WWII. In 1967, Japan introduced the three non-nuclear principles: to not possess, not produce and not permit the introduction of nuclear weapons into Japan’s territory. These principles remain untouchable to this day, referred to frequently by politicians and learned by children early on in social studies class. Aside from political reforms, a massive outpouring of literature and memorials has made the public strongly averse to nuclear weapons. The widely read manga “Hadashi no Gen (Barefoot Gen)” depicting a boy’s life affected by the atomic bomb and the Hiroshima Peace Memorial Museum displaying burned children’s clothing are some examples of the horrors of nuclear warfare deeply ingrained in the collective memory of the Japanese people. 

Japan’s decades-long national security strategy has also been well-maintained, not warranting the need for nuclear weapons. Relying on the U.S. for security worked both ways: it supported Japan’s non-nuclear status and the U.S. pursuit of arms control. Japan wanted to pursue a non-nuclear status after World War II but had to do so without jeopardizing its security. Simply disapproving of nuclear weapons would have left Japan vulnerable and defenseless if attacked. The solution to this was to rely on U.S. extended nuclear deterrence, a strategy in which Japan avoided outside attack by allying with the nuclear-armed U.S. committed to defending Japan in the event of an attack. While Japan benefited from U.S. protection, the U.S. benefited from a non-nuclear Japan in the pursuit of its non-proliferation objective. After being on the brink of nuclear war during the Cold War, U.S. foreign policy focused heavily on limiting nuclear weapon production to prevent another crisis from occurring again. Also, the U.S. benefits from limiting the number of nation-states with nuclear power. 

Since the 1950s, however, Japan clarified that it reserves the right to develop a nuclear arsenal to prevent the U.S. from taking advantage of its non-nuclear status. Japan is the only non-weapons state with full fuel cycle capabilities, meaning it can do everything from extracting uranium to disposing of nuclear waste on its own. Though there are too many legal and political barriers for Japan to produce nuclear weapons, it has always been important for Japan to keep that option open. Showing a more realistic side of what it takes to uphold a non-nuclear stance is an important aspect that has sustained Japan’s security strategy. 

This delicate but long-functioning nuclear arms control and security policy has generally worked to protect Japan from nuclear attacks. “Under the Japan-U.S. alliance, extended deterrence is working,” Kishida confirmed in a parliamentary session in March. Thus, it comes as a surprise that the Japanese public is growing open to nuclear talk. The public’s openness to nuclear sharing likely reflects a fear of deteriorating regional security, which is further reinforced by timely remarks by politicians. 

Why Japan is Open to Nuclear Sharing Talks

Japan’s public is likely to be open to nuclear sharing talks due to heightened fear after the Russian invasion of Ukraine. The impression that Ukraine was invaded by Russia despite its security assurances has triggered an interest in nuclear weapons. In the 1994 Budapest Memorandum, Ukraine agreed to give up its nuclear weapons in exchange for security promises from the U.S.  

This security assurance was not legally binding, but it was understood that there was an obligation on the U.S. to respect Ukraine’s sovereignty. This is much like how Japan functions regarding nuclear disarmament and foreign policy. However, the U.S. response was limited in the wake of the Russian invasion, avoiding any direct intervention for fear of being dragged into a war with Russia. While this limited response fulfilled the strict interpretation of the U.S. commitment under the Budapest Memorandum, it created the impression that the U.S. left Ukraine to fend for itself against a nuclear-armed aggressor. 

The growing shift in opinion in Japan in response to Ukraine thus likely shows the public drawing strong parallels between Ukraine and Japan and worrying whether the U.S. security assurance is reliable enough to ensure Japan’s long-term security. If Ukraine couldn’t count on the U.S. at the cost of giving up nuclear weapons, why should Japan? As international relations expert David Yost explains, Russia’s behavior has created incentives among the Japanese public to initiate its national nuclear weapons program because security guarantees from major powers have lost credibility.

Fear is reinforced when coupled with well-timed remarks by savvy politicians. Against the backdrop of the Russian invasion of Ukraine, one politician suggested that nuclear sharing could increase Japan’s security. Former Prime Minister Abe Shinzo, who has long yearned for a fully re-armed Japan, stated that Japan should debate nuclear sharing without “put[ting] a taboo on discussions about the reality we face.” Hundreds of articles followed the broadcast, and citizens began discussing nuclear sharing on social media. 

It’s no coincidence that this call to action came right after the Russian invasion of Ukraine. Any attempt to suggest discussing nuclear weapons would have been shut down a few months back. But Abe understands that considering Ukraine’s situation, the pursuit of nuclear weapons to safeguard Japan’s security may be seen as more legitimate. “He [Abe] thinks it’s imperative for Japan to have some kind of independent attacking power against China or North Korea. And that includes possibly a nuclear arsenal. But he also knows it would be suicidal for any politician to advocate for Japan to have nuclear weapons, so he wants to activate the debate,” said Professor Yoichi Shimada, a long-time friend and advisor to Abe. It would be hasty to say that politicians are trying to manipulate the public, but they too have their ideas about how the country should be ruled and may use good timing to steer public discourse toward that vision. 

A Malleable Public Opinion

Public opinion can easily shift in an environment clouded by fear in any country. It’s odd for Japan to be talking about nuclear sharing considering its well-respected non-nuclear stance and decades-long security system. However, fear stemming from the Russian invasion of Ukraine, amplified by influential remarks, has begun to shift public opinion in a direction unthinkable a decade ago. Security policies evolve, but when the public is using a major international event to justify military expansion, it is crucial to weigh whether their motivations are based on fear and shrewd, responsive policymaking. 

Edited by Bethlehem Samson

Yulina Goto

Yulina Goto (she/her) is a Japanese undergraduate student at Georgetown University’s School of Foreign Service. She is Japanese and grew up in the US, Japan, Denmark, and Taiwan. In her free time, she...