[Global NK Commentary] An Assessment of North Korea’s ICBM Technology and South Korea’s Countermeasures

1. Assessment of the Hwasong-17 Test Launch

On March 25, 2022, North Korea's Korean Central News Agency (KCNA) released photos and specifications of the new Hwasong-17 intercontinental ballistic missile (ICBM) launched on the 24th. KCNA reported that the Hwasong-17 reached an apogee of 6,248.5 km, flew 1,090 km for 4,052 seconds, and accurately impacted a designated area in the high seas of the East Sea. This success came just eight days after a failed test launch on March 16th. Compared to the Hwasong-15, which was successfully launched in a single attempt on November 29, 2017, the Hwasong-17 can be assessed as having a reliability rate of approximately 50%. However, the success achieved just eight days after a failure is judged to have been possible due to technical confidence. Nevertheless, given that the greatest challenge in ICBM development lies in re-entry technology—hitting ground targets by penetrating the Earth's atmosphere at speeds exceeding Mach 20—it is premature to evaluate the Hwasong-17 as a complete weapon system. The remaining tasks for North Korea in developing the Hwasong-17 are the Multiple Independently-targetable Reentry Vehicle (MIRV) technology, which guides multiple warheads to separate targets, and the Earth's atmospheric re-entry technology.

2. Prospects and Challenges for North Korea's ICBM Development

Through this test launch, North Korea showcased its rapid launch capability for ICBMs by releasing a video of the missile being launched from a Transporter-erector Launcher (TEL) in a short period. However, solid-propellant systems, which allow for faster launches than liquid-propellant systems, are ultimately preferred for ICBMs. North Korea has also displayed a model of a solid-propellant ICBM, similar in appearance to China's DF-31A and Russia's Topol-M, at a military parade in 2017. Therefore, a test launch of a solid-propellant ICBM is expected in the near future. North Korea's solid-propellant ballistic missiles are generally named "Pukguksong" (Polaris), with Pukguksong-1, -3, -4, and -5 being Submarine-launched Ballistic Missiles (SLBMs), excluding Pukguksong-2.

Once North Korea succeeds in developing a large-caliber, long-range SLBM, it is expected to adapt it for land-based deployment. The Pukguksong-2, similarly, is merely a land-based TEL-mounted version of the Pukguksong-1. The delay in North Korea's solid-propellant ICBM development is believed to be due to challenges in developing the nozzle for solid-propellant rockets. As the range increases, the time the nozzle is exposed to high temperatures and pressures lengthens, requiring advanced heat-resistant material technology. In 2017, North Korea expressed its commitment to developing such technology by releasing a bird's-eye view of new facilities at the Institute of Materials Research. As these are designated strategic materials, their import is difficult, and the technological level required for indigenous development is high; thus, North Korea is expected to take a considerable amount of time to develop related technologies. This technology is identical to the high-speed re-entry technology for nuclear warheads, making it a crucial task that North Korea must resolve.

3. After the Development of North Korea's Strategic Nuclear Weapons

While the Hwasong-17 may represent North Korea's ultimate ICBM goal, it likely does not signify the completion of its strategic nuclear weapons program. Nuclear-armed states that possess ICBMs also develop SLBMs and strategic bombers because they are useful for implementing nuclear strategy. North Korea's parallel development of strategic submarines and SLBMs, or its attempts to launch military satellites, despite its economically challenging situation, indicate that these are considered essential for its nuclear strategy. Not content with developing the Hwasong-17, capable of striking the U.S. mainland, North Korea is striving to acquire North Korean-style Anti-Access/Area Denial (A2/AD) capabilities to deter the intervention of U.S. and allied forces on the Korean Peninsula. It appears to be attempting to isolate the Korean Peninsula through the development of military satellites capable of detecting and tracking moving targets at sea, as well as missiles such as cruise missiles or Anti-ship Ballistic Missiles (ASBMs) that can strike moving maritime targets.

4. North Korea's Threat of Tactical Nuclear Weapon Development

It is assessed that North Korea is accelerating the development of nuclear weapons premised on their use on the Korean Peninsula. North Korea is developing strategic nuclear weapons like the Hwasong-17, capable of striking the U.S. mainland with nuclear weapons to deter U.S. intervention in a conflict on the peninsula. Concurrently, it is developing tactical nuclear weapons to offset its conventional force inferiority and secure military superiority around the Korean Peninsula. North Korea itself declared its goal of developing tactical nuclear weapons at the 8th Party Congress. Recently developed weapons such as the North Korean version of the Iskander, referred to as new tactical guided weapons, railway-mobile ballistic missiles, hypersonic missiles, small SLBMs, and short-to-medium range cruise missiles, all have relatively short ranges, suggesting they are intended as delivery vehicles for tactical nuclear warheads across the Korean Peninsula. North Korea is expected to continue miniaturizing nuclear warheads to a level that can be mounted on these various delivery systems. Furthermore, it is anticipated that North Korea will develop neutron bombs, which enhance lethality for various tactical purposes, and nuclear electromagnetic pulse (EMP) bombs, which can cause widespread electromagnetic destruction. These tactical nuclear weapons can be achieved by simply adding specific materials around conventional fission bombs to increase the emission of neutrons or gamma rays generated during fission, but the possibility of advancing this technology through nuclear testing cannot be ruled out.

5. South Korea's Countermeasures for North Korean Nuclear Deterrence

South Korea has strived to build nuclear deterrence through conventional means, namely its strategic strike system, Korean Missile Defense system, and overwhelming response capabilities against Weapons of Mass Destruction (WMD). Although our WMD response system relies on conventional forces, the U.S.'s newly proposed Integrated Deterrence signifies deterrence that mobilizes all capabilities possessed by both South Korea and the U.S., in addition to our conventional forces. Even if North Korea acquires the capability to strike the U.S. mainland with nuclear weapons, making the U.S. hesitant to retaliate with nuclear weapons, should North Korea use nuclear weapons on the Korean Peninsula, South Korea and the U.S. could strike North Korean leadership with their formidable conventional forces, including low-yield U.S. nuclear weapons (tactical nuclear weapons). However, North Korean leadership has fortified Pyongyang in preparation for nuclear war and is known to have long established protective facilities for evacuation. For instance, the Pyongyang subway is constructed at depths exceeding 100 meters underground, whereas Seoul has minimal nuclear protection measures in place. This "asymmetry in protection" has led to an "imbalance of fear." Because we are vulnerable to nuclear attack, we experience greater fear, while Pyongyang residents, being relatively less vulnerable, may experience less fear. Without addressing this imbalance, deterring North Korea's use of nuclear weapons will be limited. To achieve a "rebalancing of fear," there are two approaches: making North Korea feel fear or reducing our own fear. Rather than choosing one, it is advisable to prepare by prioritizing both.

※ This commentary is the Korean translation of "An Assessment of North Korea’s ICBM Technology and South Korea’s Countermeasures."

■ Lee Sang-min_Head of the North Korean Military Research Division, Center for Security Strategy Research, Korea Institute for Defense Analyses. Graduated from Korea Military Academy, he holds a Master's degree from the National Defense Academy of Japan and a Ph.D. from Tohoku University. He has served as a special advisor to the Ministry of Foreign Affairs' Korean Peninsula Peace Regime Negotiation Bureau, a member of the Ministry of National Defense's task force, a postdoctoral researcher at the Institute for Materials Research in Japan, and a visiting scholar at the University of California, Berkeley. His areas of expertise include North Korea, nuclear weapons, missiles, and weapons of mass destruction.

■ Editor: Lee Seung-yeon _EAI Researcher | Contact: 02 2277 1683 (ext. 205) | slee@eai.or.kr