For decades, South Korea has been a responsible member of the international nuclear nonproliferation regime.
As a nonnuclear-weapon state, South Korea has faithfully complied with the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and has maintained transparency in its nuclear activities under the safeguards system of the International Atomic Energy Agency (IAEA).
At the same time, based on the Korea-U.S. alliance, Seoul has relied on the U.S.’ extended deterrence commitment while trying to live up to its commitment to be a responsible NPT member state. This was not merely a policy choice but a strategic judgment grounded in international norms and alliance trust.
In recent years, the security environment on the Korean Peninsula and in East Asia has dramatically changed. Geopolitical disruptions have become a new normal. North Korea is believed to have multiple nuclear warheads and is advancing the miniaturization and diversification of its nuclear arsenal. In particular, Pyongyang’s continued development of submarine-launched ballistic missile capabilities has emerged as a fresh security threat. China is rapidly expanding its naval power and strategic weapons systems.
Facing such grave security risks, South Korea has begun to explore options to better defend itself from geopolitical risks. The situation facing South Korea raises a question: How can it effectively respond to geopolitical disruptions while continuing to stand firm in its commitment as an NPT member?
The U.S.-Korea Nuclear Cooperation Agreement serves as the central institutional foundation for this discussion. Concluded in 1974, the agreement established the framework for nuclear cooperation between the two countries. The 2015 revision expanded the scope of cooperation while maintaining strict procedural controls over uranium enrichment and spent fuel reprocessing. These provisions reflect the principles of nonproliferation, which South Korea has consistently respected.
Nevertheless, in light of the evolving security environment, it is both reasonable and necessary to consider institutional adjustments that reflect a strategic division of roles within the alliance. In particular, expanding limited and manageable forms of nuclear autonomy within the bounds of international norms and transparency would not weaken the nonproliferation regime. On the contrary, such measures could help reinforce the stability of the alliance’s deterrence architecture.
There are already precedents for such arrangements in the international community. A representative example is Japan. Under the U.S.-Japan Nuclear Cooperation Agreement concluded in 1988, Japan was granted programmatic consent for uranium enrichment and the reprocessing of spent nuclear fuel. This arrangement allowed Japan to develop nuclear fuel cycle technologies centered on the Rokkasho reprocessing plant, all of which operate under the strict safeguards system of the IAEA. Although Japan is a nonnuclear-weapon state, it has been granted a relatively high degree of autonomy in the nuclear fuel cycle based on alliance trust and international transparency.
Another recent example is the AUKUS partnership. The cooperation among the United States, the United Kingdom and Australia includes provisions to support Australia — also a nonnuclear-weapon state — in operating nuclear-powered submarines. This initiative does not clash with the existing nonproliferation regime; rather, it is being pursued in coordination with the IAEA to establish a new safeguards model. In other words, it represents an attempt to meet both military requirements and nonproliferation principles through alliance trust and transparency.
Article 14 of the IAEA Comprehensive Safeguards Agreement also provides an institutional basis for such discussions. This provision allows for adjustments to safeguards application under certain conditions when nuclear material is used for non-explosive military activities. For example, naval reactor fuel using low-enriched uranium below 20 percent enrichment clearly falls into a category distinct from weapons-grade highly enriched uranium. Such technological choices enable the management of nonexplosive military nuclear activities — such as naval propulsion — while maintaining the integrity of the nonproliferation regime.
Today, Korea is one of the world’s top 10 economies and also one of the countries with the world’s leading military capabilities. South Korea plays a significant role in global supply chains and security networks. These changes in Korea’s status in the global economy and military field have not been fully reflected in the Korea-U.S. alliance structure.
One of the most effective ways to prevent nuclear proliferation is to institutionally integrate trusted allies and deepen cooperation within transparent and well-defined norms. As demonstrated by Japan’s case and the AUKUS partnership, institutional trust among allies can strengthen — not weaken — the stability of the nonproliferation regime.
Therefore, discussions on expanding limited and manageable forms of nuclear autonomy for South Korea should be approached within this broader context. Such an approach would not weaken the alliance. Rather, it could strengthen strategic trust within the alliance in institutional terms and contribute in the long run to both the stability of the nonproliferation regime and security in Northeast Asia.
The Korea-U.S. alliance has evolved over the past 70 years on the foundation of mutual trust. Future cooperation should likewise aim to elevate that trust to a more mature institutional level. In a rapidly changing strategic environment, building a new model of cooperation — one that simultaneously strengthens alliance burden-sharing and the principles of nonproliferation — has become a shared task for both Seoul and Washington.
Moon Keun-sik is an adjunct professor of the Graduate School of Public Policy at Hanyang University in Seoul. The views expressed in this article are the author’s own and do not represent the official stance of The Korea Times.