Event Report: Nuclear Weapons, Eighty Years After the War and the Atomic Bombings

Reassessing the “Nuclear Weapons Are Cheap” Claim

The conversation began with recent issues concerning nuclear weapons and the international security environment. While nuclear proliferation continues to draw wide attention, the threat of nuclear weapons is also highly recognized internationally, particularly with regard to Russia and the Middle East. In Japan, geographically close to three nuclear-armed states, public debate on the matter has become increasingly intense in recent days.

The notion, sometimes voiced in Japan—including by members of parliament—that “nuclear weapons are cheap” was examined and rejected. North Korea was cited as an example: despite the risk of annihilation from retaliation, it invests enormous resources in nuclear development, demonstrating that nuclear weapons are anything but inexpensive. For Japan, the issue goes beyond cost, encompassing potential economic sanctions and strained relations with the United States. Instead, it was argued that conventional forces should be strengthened, being easier to use and more credible than nuclear weapons. Deterrence was described as a comprehensive framework, with conventional capabilities playing an increasingly important role that nuclear arms cannot fully replace.

Nuclear deterrence theory was also addressed. Three essential elements of deterrence were outlined: the capability to use force, the intent to use it in an emergency, and the adversary’s perception of these two factors. However, many challenges remain, including the fact that the effectiveness of deterrence cannot be confirmed until war actually breaks out, and that in certain contexts, such as suicide terrorism, deterrence fails altogether. In this regard, the importance of “deterrence by denial”—that is, convincing an adversary that an attack would be futile—was emphasized, for example by intercepting incoming missiles comprehensively so as to diminish the effectiveness of any offensive action.

North Korea’s Nuclear Posture and Implications for Integrated Deterrence

One of the most serious nuclear threats around Japan is North Korea. Uncertainty was noted regarding its nuclear strategy and objectives, which also contributes to South Korea’s anxiety. In both South Korea and Japan, debates frequently arise over nuclear sharing with the United States, as well as the possibility of developing indigenous nuclear weapons. However, it was noted that in the case of nuclear sharing with the United States, the final decision would rest with Washington. This implies that the risk of abandonment by the United States persists, and the effectiveness of such an arrangement remains uncertain.

The need for prompt discussions among Japan, the United States, and South Korea on integrated deterrence that goes beyond nuclear sharing was highlighted. At the same time, concerns were raised that U.S. credibility in protecting its allies appears to be weakening as its relative power declines, and that it is unclear whether the Trump administration would support allies in a crisis. In this context, it was argued that deterrence messaging—the signals and assurances used to convey resolve—should not rely solely on the United States, and that allies must reconsider how to strengthen mutual relationships and allocate defense budgets.

Japan’s Choices: Disarmament Goals, Security Realities, and Emerging AI Risks

Japan finds itself in a particularly difficult position: it is the only country to have experienced atomic bombings in war, and at the same time it faces one of the world’s most severe security environments while relying on the U.S. nuclear umbrella. The discussion concluded that although the ultimate goal should be a total elimination of nuclear weapons—an outcome also preferable for Japan—it is equally necessary to confront harsh security realities. This means focusing on how to deter adversaries from using nuclear weapons, how to stabilize the situation, and how to move step by step toward eventual disarmament, rather than framing the issue as a simplistic choice between abolition and developing nuclear weapons.

Finally, questions from viewers were addressed, including one concerning the relationship between geoeconomics and nuclear weapons. In this context, emerging technologies, particularly artificial intelligence, were identified as a major concern. If AI were to determine the targets and scale of nuclear strikes, humans would be unable to keep pace, and it is highly uncertain whether such a system could function effectively as a deterrent.

(Photo Credit: shutterstock)

Disclaimer: The views expressed in the Geoeconomic Online Salon do not necessarily reflect those of the API, the Institute of Geoeconomics (IOG) or any other organizations to which the author belongs.

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