North Korea recently showcased its nuclear submarine construction efforts, but multiple experts argue that technical challenges will persist even if Pyongyang receives Russian assistance.
On Thursday, Sam Tangredi, director of the Institute for Future Warfare Studies at the U.S. Naval War College, told Voice of America (VOA) that North Korea cannot independently build nuclear submarines. He explained that constructing a nuclear-powered submarine requires an extensive supply chain and infrastructure to acquire the necessary materials and knowledge for nuclear propulsion.
He particularly emphasized the difficulty of developing a nuclear reactor suitable for submarines, noting that even countries operating nuclear power plants struggle to design submarine reactors. He added that China also took considerable time to master this technology.
Bruce Bennett, senior researcher at the RAND Corporation, pointed out that even the U.S. requires 8–9 years to build its next-generation strategic nuclear submarine (SSBN), the Columbia-class. He argued that North Korea could not develop a submarine reactor without substantial Russian assistance.
Bennett further explained that nuclear submarine construction requires various advanced technologies, including noise reduction technology to evade enemy detection, submarine-launched ballistic missiles (SLBMs) development, and nuclear warheads and atmospheric reentry vehicles.
A German missile expert, Dr. Robert Schmucker, highlighted North Korea’s reliance on barges for SLBM test launches, suggesting that Pyongyang’s SLBM capabilities remain insufficient.
Bradley Martin, senior policy researcher at the RAND Corporation, acknowledged that Russia could theoretically transfer nuclear submarine technology within one to two years. However, he predicted it would take North Korea significantly longer to operate and maintain a nuclear submarine. He also stressed that even if North Korea attempted to build a nuclear submarine based on Russian designs, the technical complexity would be immense.
Makino Yoshihiro, a visiting professor at Hiroshima University and a diplomatic journalist at Asahi Shimbun, expressed skepticism in an interview with Radio Free Asia (RFA). He pointed out that submarines must be capable of withstanding immense water pressure at great depths, making North Korea’s sudden acquisition of such advanced technology highly questionable. He also noted that there is no confirmed evidence that North Korea can build a small nuclear reactor that is both safe and quiet enough for submarine use.
Makino further emphasized that Russia has never exported offensive weapons it cannot defend against. He argued that if North Korea were to possess nuclear-powered submarines and later deteriorated its relationship with Russia, Moscow could not entirely rule out the possibility of Pyongyang using nuclear weapons against it. For this reason, he stated that Russia is unlikely to provide North Korea with nuclear propulsion submarine technology.
Kim Jong Won, a research fellow at the Institute for National Security Strategy (INSS), released a report titled “The Background and Implications of North Korea’s Nuclear Submarine Construction Disclosure.” He assessed North Korea’s announcement as a strategic move to reinforce internal unity amid economic struggles and strengthen political leadership.
Externally, he noted that North Korea aims to counter U.S. strategic asset deployments during South Korea-U.S. joint military exercises by escalating its nuclear threats. Additionally, he suggested that Pyongyang seeks to enhance its negotiating leverage against Washington by showcasing its close military ties with Russia.
Meanwhile, on March 8, Rodong Sinmun, the official newspaper of the Workers’ Party of Korea, reported that Kim Jong Un inspected shipbuilding projects at keWorkers’rds and personally reviewed the construction status of a nuclear-powered strategic guided missile submarine.