Changing U.S. commitments spark nuclear armament debates, including in Japan

When the world's de facto "sheriff" for the past 80 years steps down, does that return us to a lawlessness like that of the 1800s Wild West, where every town had to find its own lawman?

Ukraine has become the poster case for what happens when you have aggressive neighbors who disregard international law and past agreements. The country's case is even more poignant, as it held the third-largest nuclear arsenal when the Cold War ended and the Soviet Union broke up. Newly independent, Ukraine joined the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and became a non-nuclear state.

To ensure its defense in this new world, Kyiv entered the Budapest Memorandum agreement in December 1994. It agreed to destroy its ballistic missiles and hand over its nuclear warheads to Russia for dismantling. In exchange, it received commitments from the United States, the United Kingdom and the Russian Federation to respect Ukraine's territorial integrity and the inviolability of its borders, and to refrain from using or threatening military force.

Then in 2014, Russia violated the agreement by invading eastern Ukraine and annexing Crimea, followed by a full-scale invasion of its neighbor in 2022, which to date has caused an estimated 1 million casualties.

Since the second inauguration of U.S. President Donald Trump, many long-held assumptions that have shaped the world order are being urgently reexamined.

As the global sheriff seems ready to ride off into the sunset, fundamental questions about Europe's ability to defend itself and NATO's future viability without the U.S. at its core are being heavily debated. America's willingness to continue extending strategic deterrence to a militarily weak and disunited Europe is under challenge. France has begun a public dialogue with Germany and other EU members about extending its modest nuclear umbrella to replace a potentially retreating U.S. Poland has stated it too must explore developing nuclear weapons quickly.

In the Indo-Pacific, the situation is similar. Over the past month, the debate over developing and deploying nuclear weapons has intensified in South Korea and Australia, driven by growing concerns over abandonment. The rapid expansion and increasing sophistication of nuclear arsenals in China and North Korea further exacerbate those concerns.

Adding more fuel to the fire is the growing cooperation among Russia, North Korea and China, which experts believe is accelerating the development of hypersonic missiles and glide bombs, multiple independently controlled warheads and even nuclear submarines. There is also genuine concern that Trump could be willing to cut a deal with North Korea and China, benefiting the retiring sheriff but leaving the townspeople to fend for themselves.

That’s a lot of change to process and assess calmly, given its impact on national security, never mind the emotional and precipitous rhetoric that dominates the media.

Also, with some members of the NPT no longer playing ball, the treaty faces a serious risk of becoming a dead letter. Once the dike breaks, it is not inconceivable to see a 50% increase in the nuclear club members in three to five years. A traditional security plan would, in addition, require the acquiring and deploying of fleets of stealth fighters, bombers, naval groups, submarines and anti-missile defense systems, among others — an enormously expensive proposition that would take decades to implement.

In today's world, tactical nuclear weapons are, in some sense, relatively crude compared to an F-35 or anti-ballistic missile defense system. But they are also cheaper and far less complex to build and deploy if you have access to the basic raw materials, engineering capabilities and simple delivery platforms.

Imagine a situation where a country is significantly behind in conventional military capabilities compared to an aggressive nuclear-armed neighbor and faces an existential threat. Would some governments view tactical nuclear weapons as a quicker, more effective path to achieving an acceptable level of deterrence?

Poland is expressing just that. If confidence in the U.S. strategic deterrence commitment is lost, could Seoul follow suit? During his first term, Trump even suggested that South Korea could develop its own nuclear weapons. Would Taiwan do the same if the U.S. removed any doubt about coming to its defense?

And what about Japan? Recently, The Japan Times published two opinion pieces from frequent commentators. Professor Brad Glosserman and Bloomberg columnist Gearoid Reidy each raised the need for Japan to begin a debate on developing nuclear weapons. Glosserman cited credible Japanese security experts who argued that U.S. deterrence can no longer be trusted, while Reidy concluded, "This debate, which must consider what becoming a nuclear power would entail, must begin now."

While intellectually I can understand the arguments, I fully appreciate how unready the Japanese are to hold an open debate, much less take active steps to develop such weapons. Nor does Japan have the courageous political leadership that such a public discussion would require. Any talk of and discrete inquiries into updated contingency plans will inevitably occur out of the public’s eye.

Given Japan's unique history in 1945, it will take more than fear or harsh rhetoric to push the country into considering the development of nuclear weapons. It will require actual abandonment, leaving it completely alone to face the combined threats of nuclear-armed China, Russia and North Korea, before the nation even opens that door. And should that ever occur, woe to those who forced it to go there.