Korea's nuclear-powered submarines could take on broader Indo-Pacific role

South Korea’s nuclear-powered submarine debate is shifting toward how the vessels would operate and whether they should go beyond peninsula defense. Experts say they could counter North Korea first, then expand into Indo-Pacific missions such as protecting sea lanes and supporting undersea cooperation with the United States. The discussion follows U.S. concerns that Seoul needs a clear security rationale for the costly program, while the government still plans to move ahead.

Moon Keun-sik said diesel-powered submarines must surface several times a day to recharge, while nuclear-powered submarines can stay submerged for a long time.

Moon said the submarines would be critical for continuously tracking North Korean submarines capable of carrying nuclear weapons.

The Ministry of National Defense aims to launch the first submarine in the mid-2030s and put it into service in the late 2030s.

The government has allocated 100 billion won, or $74.4 million, in next year’s defense budget for initial design and research work.

The ministry has formally notified the International Atomic Energy Agency of its intention to begin consultations related to the program.

Published Sep 13, 2026 3:54 pm KST

Experts point to Pyongyang deterrence, sea lane protection, alliance cooperation

North Korea's submarine Hero Kim Kun Ok, which Pyongyang claims is capable of launching tactical nuclear weapons, is unveiled during a ceremony in North Korea, Sept. 6, 2023. Yonhap

As South Korea moves ahead with plans to acquire nuclear-powered submarines, the debate is shifting from whether the country needs them to where and how they should operate.

South Korean military experts say Seoul has a strong case for acquiring nuclear-powered submarines to counter North Korea, even if their initial mission is focused on waters around the Korean Peninsula. Over time, however, they expect the submarines’ role to expand into the broader Indo-Pacific, from protecting vital sea lanes to supporting undersea cooperation with the United States.

The assessments come after a U.S. Navy official said last week that South Korea needs a clear security rationale and concept of operations for the costly assets, reviving questions over whether Seoul needs nuclear-powered submarines if they are to operate mainly close to home.

Moon Keun-sik, a submarine expert who formerly headed the nuclear-powered submarine project team at Navy Headquarters and is now a professor at the Graduate School of Public Policy at Hanyang University in Seoul, said that argument overlooks the ability of nuclear-powered submarines to remain submerged and undetected for extended periods.

“Diesel-powered submarines have to come close to the surface several times a day to recharge their batteries, exposing themselves in the process,” Moon told The Korea Times. “A nuclear-powered submarine can remain submerged for a long time and surface only when necessary.”

That capability would be critical for continuously tracking North Korean submarines capable of carrying nuclear weapons, he said. Pyongyang is also pursuing a nuclear-powered submarine, which would be difficult for a conventional diesel-electric submarine to keep pace with.

Moon, however, said Seoul should not confine its future nuclear-powered submarine fleet to the peninsula.

South Korea relies heavily on sea lanes that carry energy supplies from the Middle East through the Indian Ocean and the Strait of Malacca. In a contingency around the Strait of Hormuz or other critical waterways, nuclear-powered submarines could be rapidly dispatched for long-range missions, he said.

President Lee Jae Myung discusses a plan for developing nuclear-powered submarines during the inaugural Future Defense Strategy Meeting in Jinhae, Changwon, South Gyeongsang Province, May 26. Korea Times photo by Wang Tae-seok

Moon has also argued that the submarines could protect South Korea’s sea lines of communication and enable more reciprocal undersea cooperation with the U.S. Navy in the Indo-Pacific, rather than leaving Seoul dependent on U.S. nuclear-powered submarines.

Cheng Seong-chang, vice president of the Sejong Institute, similarly said the primary mission should be deterring North Korea’s nuclear-powered submarines, while the strategic implications would extend further.

“The primary objective is, of course, to counter North Korean nuclear-powered submarines,” Cheong said. “But secondarily, they could help maintain the balance of power in Northeast Asia and take the South Korea-U.S. alliance to another level.”

He said a South Korean nuclear-powered submarine fleet would inevitably complicate China’s strategic calculations and could ultimately support U.S. strategy in the Indo-Pacific.

The debate follows remarks last week by a U.S. Navy official who said Seoul must identify a “valid reason” for acquiring nuclear-powered submarines and warned against pursuing them simply for national prestige given their enormous cost. Adm. Daryl Caudle, the U.S. chief of naval operations, previously suggested that South Korea might not need such submarines if it had no plans to operate them beyond nearby waters.

Seoul, meanwhile, is moving ahead with the program.

President Lee Jae Myung last month described the project as one that could symbolize the future of a stronger, more constructive South Korea-U.S. alliance and called for faster progress.

The Ministry of National Defense aims to launch the first submarine in the mid-2030s and put it into service in the late 2030s. It says the vessel’s prolonged underwater endurance and high mobility would make it a key asset against North Korea’s submarine-based nuclear and missile threats.

The government has also allocated 100 billion won ($74.4 million) in next year’s defense budget for initial design and research work and has formally notified the International Atomic Energy Agency of its intention to begin consultations related to the program.

Defense minister nominee Kang Shin-chul has described nuclear-powered submarines as providing a “persistent and stealthy deterrent” against North Korea, while also pointing to their potential role in securing sea lanes and their broader impact on the defense, nuclear energy and shipbuilding industries.

The U.S. Congress is also taking a closer look. The Senate Armed Services Committee has called for an assessment of how South Korea’s nuclear-powered submarine program could affect Indo-Pacific security, proliferation risks, costs and the scope of future bilateral cooperation.

韩国关于核动力潜艇的争论正转向这些潜艇的作战方式以及它们是否应该超越半岛防御的范畴。专家表示，它们可以首先用于对抗朝鲜，然后扩展到印太地区任务，例如保护海上航道和支持与美国的水下合作。此前，美国曾担忧首尔需要为这项耗资巨大的项目提供明确的安全理由，而韩国政府仍计划推进该项目。

文根植表示，柴油动力潜艇每天必须浮出水面几次进行充电，而核动力潜艇可以长时间潜航。

文在寅表示，这些潜艇对于持续追踪能够携带核武器的朝鲜潜艇至关重要。

国防部计划在 2030 年代中期建造第一艘潜艇，并在 2030 年代后期投入使用。

政府已在明年的国防预算中拨款 1000 亿韩元（约合 7440 万美元）用于初步设计和研究工作。

该部已正式通知国际原子能机构，其打算就该计划展开磋商。

发布于2026年9月13日下午3:54（韩国标准时间）

专家指出，平壤此举旨在威慑、保护海上航道和加强联盟合作。

2023年9月6日，朝鲜举行仪式，朝鲜“英雄金坤玉”号潜艇正式亮相。平壤方面声称该潜艇具备发射战术核武器的能力。（韩联社）

随着韩国推进其购置核动力潜艇的计划，争论的焦点也从韩国是否需要核动力潜艇转移到核动力潜艇应该在何处以及如何运行。

韩国军事专家表示，首尔有充分的理由采购核动力潜艇以对抗朝鲜，即便其初期任务主要集中在朝鲜半岛周边海域。然而，他们预计随着时间的推移，这些潜艇的作用将扩展到更广阔的印太地区，从保护重要海上航道到支持与美国的水下合作。

此前，一位美国海军官员上周表示，韩国需要为这些昂贵的资产提供明确的安全理由和作战概念，这再次引发了人们对首尔是否需要核动力潜艇的质疑，因为这些潜艇主要在近海区域活动。

曾任海军总部核动力潜艇项目组组长、现任首尔汉阳大学公共政策研究生院教授的潜艇专家文根植表示，这种说法忽略了核动力潜艇能够长时间潜航而不被发现的能力。

“柴油动力潜艇每天都必须多次接近水面充电，在这个过程中会暴露自身，”文在寅告诉《韩国时报》。“核动力潜艇可以长时间潜航，只在必要时才浮出水面。”

他表示，这种能力对于持续追踪朝鲜可携带核武器的潜艇至关重要。平壤也在研发核动力潜艇，而传统的柴电潜艇很难与之匹敌。

然而，文在寅表示，首尔不应将其未来的核动力潜艇舰队局限于朝鲜半岛。

韩国严重依赖经由印度洋和马六甲海峡从中东运送能源的海上航线。他表示，一旦霍尔木兹海峡或其他关键水道发生紧急情况，核动力潜艇可以迅速部署执行远程任务。

5月26日，韩国总统李在明在庆尚南道昌原市镇海举行的首届未来国防战略会议上，讨论了发展核动力潜艇的计划。（韩国时报 王泰硕 摄）

文在寅还认为，这些潜艇可以保护韩国的海上交通线，并促进韩国与美国海军在印太地区开展更多互惠的水下合作，而不是让首尔依赖美国的核动力潜艇。

世宗研究所副所长郑成昌也表示，首要任务应该是威慑朝鲜的核动力潜艇，而其战略意义则更为深远。

“首要目标当然是遏制朝鲜的核动力潜艇，”郑先生说。“但其次，它们有助于维护东北亚的权力平衡，并将韩美同盟提升到一个新的水平。”

他表示，韩国的核动力潜艇舰队势必会使中国的战略考量变得复杂，并最终可能支持美国在印太地区的战略。

这场争论源于上周一位美国海军官员的言论。该官员表示，首尔必须为采购核动力潜艇给出“正当理由”，并警告称，鉴于核动力潜艇的巨额成本，不应仅仅为了提升国家声望而追求此类潜艇。美国海军作战部长达里尔·考德尔海军上将此前曾表示，如果韩国没有计划在近海以外海域使用核动力潜艇，那么它可能并不需要这类潜艇。

与此同时，首尔方面正在推进该项目。

李在明总统上个月将该项目描述为象征着未来更强大、更具建设性的韩美同盟，并呼吁加快推进速度。

韩国国防部计划在2030年代中期建造首艘潜艇，并在2030年代后期投入使用。国防部表示，该潜艇的超长水下续航能力和高机动性将使其成为对抗朝鲜潜射核武器和导弹威胁的关键武器。

政府还在明年的国防预算中拨款 1000 亿韩元（7440 万美元）用于初步设计和研究工作，并已正式通知国际原子能机构，打算就该计划展开磋商。

国防部长提名人姜信哲表示，核动力潜艇对朝鲜构成“持续且隐蔽的威慑”，同时还指出它们在保障海上航道安全方面的潜在作用，以及它们对国防、核能和造船业的更广泛影响。

美国国会也在密切关注此事。参议院军事委员会已要求评估韩国核动力潜艇计划可能对印太地区安全、核扩散风险、成本以及未来双边合作范围产生的影响。