Should Japan Have a Nuclear-Sharing Agreement?

By Koichi Hamada, Former Special Adviser, Former Japanese Prime Minister Shinzo Abe

As the only country to suffer a nuclear attack, Japan has a unique responsibility to fight for the elimination of nuclear weapons, writes Koichi Hamada. But that does not mean it should not be able to protect itself with its own nuclear deterrent.

World War II transformed the world, but nowhere more than Japan. The only country in the world to have suffered the devastation of nuclear bombs, Japan rejected the militarism that had defined its politics for decades. In 1947, it adopted a pacifist constitution, drafted largely by Americans, which formally renounced war as the right of a sovereign nation and the threat or use of force as a means of resolving disputes. Needless to say, Japan would not be seeking to become a nuclear power.

But while the world changed profoundly in the ensuing decades, Japan’s security policy largely did not. Japan’s security remained the responsibility of the United States, which had pledged to defend the country in the event of armed attack. Accordingly, the US maintained a significant troop presence and several bases in Japan, and extended its nuclear umbrella to the country.

Even this was too much militarism for many Japanese, who remained overwhelmingly committed to pacifism and, in many cases, opposed the presence of US bases on Japanese soil. When Prime Minister Nobusuke Kishi sought in 1960 to increase Japan’s role in its own defence, student protests erupted. Even I – not generally an activist during my time at university – participated in the demonstrations. In later years, moreover, I wrote the occasional commentary applying game-theoretic thinking to make the case for pacifism during the Cold War – making me one of many voices in the media touting such an approach.

In recent years, however, the risks to Japan’s security have grown substantially. The late Japanese Prime Minister Abe Shinzō, for whom I served as an economic adviser, began sounding the alarm a decade ago, arguing that intensifying threats – not least from China – demanded an updated security posture. To that end, Abe’s government introduced a National Security Strategy, revised the National Defense Program Guidelines and Midterm Defense Plan, and in 2014, reinterpreted Japan’s constitution to allow Japanese troops to come to the aid of an ally under attack.

Abe’s advocacy of a more active role for Japan in managing its own security gained new impetus after US President Donald Trump was elected in 2016. As Abe once confessed to me in a private conversation, he was not entirely convinced that Japan could depend on Trump’s White House to defend it. But Abe ran up against significant popular resistance, rooted in enduring antipathy to militarism, and he never achieved his goal of revising Japan’s constitution.

Now, however, resistance to strengthening Japan’s hard power seems to be weakening. Russian President Vladimir Putin’s invasion of Ukraine – an effort to revive the empire of his fantasies – has raised fears that Chinese President Xi Jinping may decide to launch a similar invasion of Taiwan for his personal glorification as the ruler of a Sinocentric universe. This would upend security in Asia, just as the Ukraine war has done in Europe, potentially even opening the way for an attack on Japan. Compounding Japan’s sense of vulnerability, North Korean leader Kim Jong-un continues to fire missiles toward its shores.

Abe’s successor, Prime Minister Fumio Kishida, has now taken up the mantle of bolstering Japanese security. In recent months, the longtime dove has announced a plan that would nearly double Japan’s military spending and, under the new National Security Strategy, use some of the increase to acquire counterstrike capabilities.

But no discussion of defence nowadays can ignore nuclear weapons. After all, it is Russia’s nuclear arsenal that deterred the US and NATO from mounting a direct defence of Ukraine. Well aware of his trump card, Putin has repeatedly issued veiled threats to deploy nuclear weapons in Ukraine. Moreover, he has now suspended Russia’s participation in New START, the last remaining nuclear treaty with the US.

Beyond maintaining its “no-limits” partnership with Russia – which makes Russia’s nuclear arsenal an indirect threat to those China might seek to subjugate – China continues to expand its own nuclear arsenal: the US Pentagon reports that the country will possess 1,500 nuclear weapons within the next decade. And a nuclear arsenal has of course long been a goal of the Kim regime.

Last year, Abe argued that it was time for Japan to hold an honest discussion on “how security is maintained around the world” and to consider a nuclear-sharing agreement, with Japan potentially joining NATO countries in hosting American nuclear weapons. The call was contentious, to say the least, and was quickly rejected by Kishida.

Opponents of the proposal argue that holding nuclear weapons would amount to a betrayal of Japan’s pacifist constitution and the three non-nuclear principles – that it will not produce or possess nuclear weapons, nor allow them on its territory – to which it has long adhered. In fact, they insist, Japan should be at the forefront of the quest to abolish nuclear weapons globally.

But this is a false dilemma. Abe himself believed that Japan must work to advance the goal of eliminating nuclear arms, not least because the hellish experiences of Hiroshima and Nagasaki lend the country credibility in this area. But this effort does not preclude self-defence. If you have been beaten by a stick, does that mean that you can never carry a stick of your own to deter another beating? And with the approach Abe proposed, the stick would merely be borrowed. In other words, Japan could employ nuclear deterrence without becoming a nuclear power.

While Japan may be softening to the idea of taking a more active role in its own security, persuading the Japanese to accept the idea of hosting nuclear weapons will not be easy. As for the US, some politicians might be less willing to share such arms with an Asian ally than with Europeans. But as Abe said, discussion of a nuclear-sharing agreement should not be taboo. In fact, the idea may well be Abe’s final critical legacy for his beloved country.


Koichi Hamada, Professor Emeritus at Yale University, was a special adviser to former Japanese Prime Minister Abe Shinzō.

Copyright: Project Syndicate, 2023. www.project-syndicate.org