When North Korea recently revealed that it is constructing a nuclear-armed, nuclear-powered ballistic missile submarine (SSBN), there was no response from China. By contrast, when South Korea and the United States announced a security agreement to construct conventionally-armed, nuclear-powered submarines (SSN) and enrich uranium at last October’s leaders’ summit, Chinese state media and military experts claimed that South Korea’s SSNs would undermine the Nuclear Non-Proliferation Treaty (NPT) and pose a high risk of nuclear proliferation. They portrayed South Korea as if it were making a dangerous choice in violation of international norms. However, behind these claims is the intention to obstruct the expansion of South Korea’s defense capabilities and the development of the ROK–U.S. alliance.

China’s “nuclear non-proliferation” claims directly contradict its own actions. Over the past several years, China has significantly strengthened its nuclear forces by building a full nuclear triad consisting of intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and strategic bombers. According to the U.S. Department of Defense’s 2025 Report on Chinese Military Power, China currently possesses approximately 600 nuclear warheads, a number projected to reach 1,000 by around 2030. In addition to its existing arsenal of roughly 400 ICBMs, China is constructing 100 new nuclear missile silos. This represents a dramatic increase compared to the early 2000s, when China possessed around 230 nuclear warheads and only about 20 ICBMs. China claims that its nuclear buildup is a “defensive measure,” but this directly contradicts Article VI of the NPT, which calls on nuclear-weapon states to pursue gradual nuclear disarmament.

A more serious problem is China’s de facto toleration of North Korea’s nuclear buildup, which is a direct challenge to the international non-proliferation regime. North Korea has advanced the miniaturization of nuclear warheads and brought its SLBM capabilities to the stage of operational deployment. In addition, Kim Jong Un has pledged to “exponentially” increase his nuclear arsenal, but China has defended this under the pretext of North Korea’s “legitimate security concerns” while blocking sanctions and resolutions at the United Nations Security Council together with Russia.

China’s attitude of taking issue with South Korea’s SSNs and defense capability buildup is a blatant double standard. South Korea’s SSNs will be defensive assets that do not carry nuclear warheads and are fully compatible with the international non-proliferation regime. By contrast, North Korea’s SLBMs and SSBNs, which are explicitly intended to carry nuclear warheads, represent textbook violations of non-proliferation norms.

Given North Korea’s growing nuclear and missile threats and China’s rapid expansion of its nuclear forces, mere “promises of extended deterrence” by the United States are insufficient to guarantee South Korea’s security. South Korea must therefore pursue the redeployment of U.S. tactical nuclear weapons on the Korean Peninsula in order to send a clear and unmistakable deterrent signal to both North Korea and China. Just as NATO’s forward deployment of tactical nuclear weapons in Europe during the Cold War deterred Soviet miscalculation, the Korean Peninsula likewise requires a credible and visible deterrent.

Furthermore, as the authoritarian coalition among China, North Korea, and Russia deepens in Asia, there is also a need for an Asian version of NATO. With South Korea, the United States, and Japan as its axes, and linked with Australia, the Philippines, and India, such a multilayered cooperative grouping is essential to deter China’s unilateral military expansion.

South Korea must now make its position clear: our security is our prerogative, and no other country has the right to dictate our choices. The redeployment of tactical nuclear weapons and establishment of an Asian version of NATO are not provocations but rather deterrence measures, which are realistic choices to safeguard peace on the Korean Peninsula and in Northeast Asia.

* The view expressed herein was published on January 2 in The Dong-A Ilbo and does not necessarily reflect the views of The Asan Institute for Policy Studies.