Photo: Kim Jae-Hwan/SOPA Images/LightRocket/Getty Images
On March 8, Kim Jong-un reportedly visited unidentified shipyards, where he was photographed with a large vessel North Korea called a “nuclear-powered strategic guided missile submarine.” If this report is true, it would mark the first time the country has unveiled a glimpse of its first nuclear-powered submarine.
Q1: What is the significance of North Korea’s statement?
A1: North Korea’s pursuit of nuclear-powered submarines should not be seen as a surprise to anyone. The country has a long record of expressing its ambitions to develop this advanced submarine technology. Its goal of constructing a nuclear-powered submarine was first announced in January 2021 when Kim Jong-un announced a five-year weapons development plan at the 8th Congress of the Workers’ Party of Korea. In September 2023, when North Korea revealed its first true ballistic missile submarine, the Hero Kim Kun Ok, Kim emphasized his desire for the navy to “go nuclear” and stressed the importance of building a nuclear-powered submarine. During his observation of the submarine-launched cruise missile test in January 2024, Kim referenced the construction of a nuclear submarine once again, highlighting the priority he places on the nuclear-powered submarine program.
Q2: Is this a result of military cooperation between Russia and North Korea?
A2: It is highly likely that the country could develop a nuclear-powered submarine only with Russia’s help. Since the start of the Ukraine war in February 2022, military cooperation between North Korea and Russia has rapidly expanded. North Korea has supplied munitions and troops to Russia in exchange for food, oil, cash, and commercial benefits. This transactional relationship, which has been well documented by CSIS satellite imagery, shows increased border activity around the time of Kim Jong-un’s summit meeting with Putin in September 2023. According to another study, Russia’s arms deals with North Korea are estimated to be worth up to $5.52 billion.
However, as the CSIS Korea Chair noted in our September 2023 report, Russia might send high-end technology to North Korea in exchange for arms and missiles, including (1) ballistic missile technology for international continental ballistic missiles, (2) nuclear-powered submarines, and (3) advanced technology for satellites.
Q3: Are we sure of Russia’s advanced technology transfer to North Korea?
A3: CSIS has been successful in tracking railway traffic between Russia and North Korea at the Tumangang-Khasan railway crossing. But tracking technology transfer has been much harder because there are really no imagery signatures available.
However, we believe Russia’s technology transfer is likely to be the case. First, Kim Jong-un has been clear about what he wants, as evidenced by the sites he visited during his September 2023 trip to Russia, including Russian Pacific Fleet headquarters and frigate Marshal Shaposhnikov in Vladivostok. It is highly doubtful that Kim traveled all the way to Vladivostok just for food. Kim’s willingness to take more than 20 hours of train ride to Vladivostok evinces his strong commitment to building a modern naval program.
Second, U.S. officials’ statements have evolved from speculative to assertive with regard to Russia’s high-end technology transfer to North Korea. In March 2024, as part of the annual threat assessment, Avril Haines, the director of national intelligence at the time, surmised that Russia potentially could be dropping its long-held nonproliferation norms in its interaction with North Korea. Mira Rapp-Hooper, a senior White House official, later acknowledged Russian ballistic missile production equipment as desired by North Korea. White House National Security Communications Advisor John Kirby also confirmed that the United States has seen some technology sharing between the two.
Q4: What are the policy implications?
A4: First, North Korea’s nuclear-powered submarine will complicate U.S. anti-submarine warfare missions, especially in dual contingencies on the Korean peninsula and in the Taiwan Strait.
Second, Russian cooperation on North Korean nuclear submarines is a manifestation of how the new strategic partnership between the two countries is even stronger than in the Cold War days. During the Cold War, the Soviet Union was reluctant to give North Korea such advanced weapons technology. For example, in 1964, it provided a 4 megawatt thermal IRT-2000 research reactor to North Korea, on the explicit commitment that North Korea joins the Non-Proliferation Treaty.
Third, the level of Russia’s advanced technology transfer to North Korea (DPRK) reflects the changing balance of influence between Russia and China over its communist neighbor. China has been unable to stop North Korea’s arms supply and troop deployment to Russia, which suggests that Beijing has lost its control over its neighbor.
Fourth, Russia-DPRK cooperation reduces North Korea’s incentive to engage in dialogue with the United States. As a result of North Korea’s support of Russia in the Ukraine War, it is getting money, fuel, food, sanctions relief, and de facto recognition as a nuclear power—all of which would be hard, if not impossible, for the Trump administration to proffer.
Victor Cha is president of the Geopolitics and Foreign Policy Department and Korea Chair at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Ellen Kim is senior fellow of the Korea Chair at CSIS.
