Military Officials Speak Out Successively, Taking the Opportunity to Share "Security Responsibilities," the U.S. Disturbs East Asia, Encouraging Japan and South Korea to Introduce Nuclear Submarines

[Global Times Special Correspondent Wu Yan, Global Times Reporter Liu Yang] Nuclear submarines are symbols of great power maritime authority, and due to their formidable combat capabilities and potential nuclear proliferation risks, their technology export is generally restricted. However, in recent years, the U.S. government has taken the opposite approach, promoting Australia's AUKUS nuclear submarine project while simultaneously encouraging South Korea and Japan to acquire nuclear submarines, bringing the risk of an underwater arms race to East Asia.

Continuously Promoting South Korea's Nuclear Submarine Program

According to a report by South Korea's Seoul Economic Daily on November 8, the chairman of the National Defense Committee of the South Korean National Assembly, Jeon Seong-jun, stated that after his meeting with the commander of the U.S. Pacific Fleet, the U.S. side expressed a willingness to actively cooperate on South Korea's plan to acquire nuclear-powered submarines. A delegation led by Jeon Seong-jun visited the U.S. Pacific Command and its subordinate units in Hawaii from November 1 to 5, discussing alliance issues with senior U.S. military commanders. According to Jeon Seong-jun, Admiral Stephen T. Koehler, commander of the U.S. Pacific Fleet, stated that South Korea's acquisition of nuclear submarines "would contribute to the development of the alliance between the two countries." Jeon Seong-jun mentioned that when he requested cooperation on the submarine project, Koehler conveyed the U.S. position, stating, "If a policy decision is reached between South Korea and the U.S., the U.S. will actively cooperate." Koehler praised the capabilities demonstrated by the South Korean military during the "Rim of the Pacific-2026" military exercise and promised continued cooperation to expand defense relations related to shipbuilding.

This is not the first time the U.S. has expressed support for South Korea's development of nuclear submarines. On October 30 last year, U.S. President Trump stated on social media that he had approved South Korea's construction of nuclear submarines, claiming that the submarines would be built at the Philadelphia shipyard acquired by South Korea. U.S. Secretary of Defense Mark Esper also confirmed at a press conference held in South Korea on November 4 of that year, "I would like to reiterate that President Trump has approved South Korea's construction of nuclear-powered submarines."

In recent years, South Korea has vigorously promoted its independent nuclear submarine program, citing that "neighboring countries are rapidly enhancing their underwater nuclear capabilities, making it difficult to effectively respond to potential threats." However, South Korean media previously acknowledged that while South Korea has the capability to build large-tonnage hulls and onboard weapon systems for nuclear submarines, it still requires U.S. assistance for the most critical nuclear power reactor. According to the U.S.-South Korea Nuclear Cooperation Agreement, South Korea can only enrich uranium to below 20% purity with prior written consent from the U.S. This also means that South Korea needs to obtain permission from the U.S. to acquire nuclear fuel for its nuclear submarines.

After Trump and Esper expressed support for South Korea's nuclear submarine construction last year, the project's progress has noticeably accelerated. According to the Korea Herald, on May 26 of this year, during the first meeting of South Korea's Future Defense Strategy Committee, Defense Minister An Gye-beom outlined the "Basic Plan for the Development of South Korea's Nuclear-Powered Submarine," confirming that South Korea's first nuclear submarine will use low-enriched uranium as fuel.

Acting as a Backer for Japan's Nuclear Submarine Project

The U.S. support for South Korea's nuclear submarine program has, to some extent, stimulated Japan. Previously, Japan had been quietly advancing its nuclear submarine program. An expert group from the Ministry of Defense responsible for strengthening Japan's defense capabilities suggested in a report in September 2025 that the Japan Maritime Self-Defense Force should study the adoption of "next-generation power sources" for submarines equipped with vertical launch systems (VLS), which is interpreted as a hint towards nuclear propulsion. This is also the first time an official advisory body in Japan has publicly supported the concept of nuclear submarines.

After Trump signaled the green light for South Korea's nuclear submarine project, Japan's Defense Minister Kono Taro, who has long advocated that Japan should possess nuclear submarines, publicly stated in November of that year that, given South Korea's advancement of its nuclear submarine project, "the environment surrounding Japan is becoming so severe that we must discuss whether to continue using diesel power or choose nuclear-powered submarines." Japan's Asahi Shimbun interpreted this as the movements in South Korea adding momentum to the debate over Japan acquiring nuclear submarines. The U.S. has further fueled this trend. In December 2025, Kono Taro visited the U.S. Navy's Yokosuka base in Japan and specifically boarded the U.S. Navy's Seawolf-class nuclear submarine, which Japanese media interpreted as tacit approval from the U.S. for Japan's introduction of nuclear submarines.

Subsequently, Japan, disregarding opposition from neighboring countries such as China, insisted on advancing its nuclear submarine introduction project, with the U.S. playing a behind-the-scenes role as a backer. According to Kyodo News, on September 9 of this year, a U.S. Navy official expressed "affirmation" regarding Japan's exploration of acquiring nuclear submarines during a media interview in Hawaii. He stated that Japan already has nuclear power plants and possesses the foundational technology for power generation, and that both nuclear power plants and nuclear submarines "utilize nuclear energy," indicating a technical commonality. Other U.S. Navy officials and experts have suggested that Tokyo "should consider purchasing nuclear submarines," with the aim of "helping the Japan Self-Defense Forces more effectively deter China." A report from the American Enterprise Institute advocates that Japanese nuclear submarines could "play a greater role in countering the expansion and modernization of the Chinese Navy."

Triggering an Underwater Arms Race in East Asia?

Chinese experts interviewed by the Global Times stated that the U.S. is promoting the development of nuclear submarine programs in South Korea and Japan for dual purposes. Firstly, the U.S. hopes that by enabling South Korea and Japan to possess nuclear submarines, they can better share the so-called "security responsibilities" with the U.S., helping to reduce U.S. military investment in Northeast Asia and the entire Asia-Pacific region. Due to the deterioration of the overall condition of the U.S. Navy, particularly the "gap" in attack submarines due to inadequate maintenance, the number of nuclear submarines that the U.S. can deploy in the Pacific is insufficient, necessitating reliance on the support of allies. It is under this line of thinking that the U.S. has successively promoted Australia's AUKUS nuclear submarine project and South Korea's nuclear submarine project, while tacitly allowing Japan to break through the red line in developing nuclear submarines.

On the other hand, the U.S. also hopes that South Korea's nuclear submarine project will assist in the construction of U.S. nuclear submarines. In recent years, due to outdated shipyard equipment and processes, the construction speed of U.S. nuclear submarines has significantly lagged behind the planned schedule. According to Trump's unilateral request, South Korea's nuclear submarines will be advanced at the U.S. shipyard in Philadelphia. This also means that the South Korean nuclear submarine project will not only bring new orders to the U.S. shipbuilding industry but also, after introducing South Korea's advanced shipbuilding experience and technology, will benefit the recovery of related U.S. industries, create jobs, and promote the development of upstream and downstream industrial chains.

Experts warn that the consecutive promotion of nuclear submarine projects by Japan and South Korea will inevitably trigger an arms race in nuclear submarines in the East Asian region. In fact, the nuclear submarine plans of these two countries have already provoked opposition from neighboring countries. Regarding the cooperation between the U.S. and South Korea on nuclear-powered submarines and uranium enrichment, some Chinese experts have stated that this move will undermine the non-proliferation system. Chinese Foreign Ministry spokesperson Lin Jian stated that regarding U.S.-South Korea nuclear submarine cooperation, China has repeatedly expressed its position on related issues and hopes that South Korea will handle them prudently. Concerning Japan's nuclear submarine plan, the Chinese Foreign Ministry spokesperson criticized that Japan, as a defeated nation in World War II and a non-nuclear weapon state under the Treaty on the Non-Proliferation of Nuclear Weapons, has "no room for so-called 'discussion'" on nuclear issues. Chinese Foreign Ministry spokesperson Mao Ning explicitly pointed out that the current Japanese regime's behavior of "seeking to abandon the 'three non-nuclear principles' and introduce nuclear submarines" is part of its "expanding nuclear ambitions" and "gradual nuclear loosening," which seriously threatens regional peace. In October of this year, in response to Japan's revision of the "three security documents" and consideration of including discussions on introducing nuclear-powered submarines, Chinese Defense Ministry spokesperson Chen Xi criticized that "the new militarism is a gray rhino that is mutating out of control and accelerating its charge."