Inauguration of the Jang Bogo H Project
On May 27, 2023, it was revealed that South Korea is initiating a new program to build nuclear-powered submarines, designated the Jang Bogo H Project. This initiative comes as a direct response to North Korea's development of its own nuclear submarine. The project's name honors the first South Korean submarine ever built, and the new vessels will be armed with conventional weapons only. Notably, Seoul has no intention of acquiring nuclear weapons, and the reactors for these submarines will operate on low-enriched uranium.
All submarines in the series will be constructed exclusively at South Korean shipyards, with the first vessel expected to launch in the mid-2030s. Commissioning of the new submarines is anticipated closer to the end of the decade. To carry out this project, South Korea will collaborate with the International Atomic Energy Agency (IAEA). In November 2025, the country reached an agreement with the United States to work jointly in this field, which is expected to bolster maritime security.
Submarine Development and International Cooperation
North Korea's nuclear submarine development became public in 2025, when Pyongyang announced plans to build its own strategic submarine equipped with guided missiles and a nuclear propulsion system. While South Korea accelerates its efforts to produce new submarines, Hanwha Ocean has already built a diesel-electric KSS-III class submarine, currently docked in Canada as a demonstration model. Meanwhile, the Canadian government is seeking a contractor to purchase 12 conventional submarines.
“The goal of this project is to enhance operational endurance and survivability, thereby strengthening maritime security capabilities and achieving a higher level of deterrence, particularly against the Democratic People’s Republic of Korea (DPRK).”
South Korean Ministry of Defense
This project marks a significant step for South Korea in reinforcing its defense capabilities within the region.
The launch of the Jang Bogo H Project underscores the growing tension on the Korean Peninsula and the need for South Korea to fortify its defense posture. Amid North Korea's active development of military technologies, these new submarines could become a critical element in Seoul's deterrence strategy and the protection of national interests. Cooperation with the IAEA and the United States also signals South Korea's commitment to adhering to international nuclear safety standards, which may enhance its global reputation as a responsible state.
As South Korea advances its submarine program, it is crucial to understand the broader context of regional security dynamics. The ongoing developments in North Korea's military capabilities are prompting Seoul to bolster its defenses. For a deeper insight into how these efforts are shaping the security landscape in East Asia, read more about South Korea's strategic initiatives to counter North Korea's advancements.