South Korean Hypersonic Ambitions: The Implications of Hypersonic Weapons on the Korean Peninsula

In August 2020, South Korean Defense Minister Jeong Kyeong-Doo pledged to accelerate hypersonic missile development at the Agency for Defense Development’s 50th-anniversary celebration.^[1] In line with long-term aims to achieve “complete missile sovereignty,”^[2] Jeong’s statement marked the first public announcement on the country’s intentions to build hypersonic weapons––highly maneuverable missiles that can travel at five times the speed of sound, and higher, for sustained periods. Experts predict that less than a decade is needed to prepare these weapons for military deployment as evidenced by the rapidly intensifying hypersonic weapons arms race between China, Russia, and the United States.^[3] Such risks, intensified by the novel features of hypersonics, warrant greater attention on how the Republic of Korea’s entry into the emerging hypersonic arms race may impact nuclear security and stability on the Korean peninsula.

Strategic Motivations

What sets hypersonic missiles^[4] apart from traditional ballistic and cruise missiles is their ability to travel at extremely high speeds and maneuver without a fixed flight path.^[5] The immense velocity, extensive maneuverability, and wide altitude range of hypersonic weapons make them nearly imperceptible to existing surveillance systems, presenting challenges even for the strongest of missile defenses. Seoul’s military anticipates deploying hypersonic missiles against Pyongyang to boost current conventional deterrence and missile capabilities. The existing “nuclear-WMD response system” (핵·WMD 대응체계)^[6]––intended to prevent, pre-empt, defend, retaliate, and decapitate––has faced much criticism regarding its effectiveness in countering North Korean nuclear and missile attacks. Without a nuclear weapons program, South Korean military assets are technologically insufficient to meet the aims of the nuclear-WMD deterrence system.^[7]

The nuclear-WMD response system consists of three components: Strategic Target Strike, Korean Missile Defense, and Overwhelming Response. With respect to strategic target strikes, general assessments suggest that the South Korean military’s ability to gather information and attack the North’s weapons is inadequate. The limitations of C4ISR (Command, Control, Communications, Computers Intelligence, Surveillance, and Reconstruction) make it difficult to identify the intent behind North Korean attacks within the 30 minutes needed for preparing a response. Even if attack information is obtained in advance, the reality is that the South does not possess the technological capacity to prevent incoming attacks: a simulation operation revealed that the probability of success would only be around 0.12-2.64% if the “kill-chain” system were to be performed on a single North Korean transporter ejector launcher in the ballistic missile operation area (BMOA).^[8]  In terms of Korean Missile Defense, despite plans to deploy L-SAM for multi-layered defense, there remains disagreement over whether it can effectively intercept high-angle projectiles (such as Musudan and Hwaseong),^[9] not to mention the need for a system that can intercept before the final stage to prevent incidental damage caused by falling debris. Likewise, the ROK military lacks the range and diversity of weapons systems requisite for the Overwhelming Response system.

As a deterrent against nuclear attack,^[10] hypersonic weapons would eliminate the need for the Republic of Korea (ROK) to develop its own nuclear program, resolving pro-nuclear aspirations that stem largely from perceptions of achieving a balance of power between the two Koreas. Those who support Seoul’s ambitions for going nuclear point to the insufficiency of a purely conventional response and the progressively tenuous reliance on US nuclear deterrence.^[11] A hypersonic weapons system offers a compressed response time, buttressing overall defense capabilities and improving the likelihood of intercepting ballistic missiles during the ascent phase.^[12] The perceived advance nature of hypersonics will mitigate the dangers involved with relying solely on conventionally armed missiles and a ballistic missile defense against nuclear threats, albeit persistent concerns with regard to the US nuclear umbrella.^[13] In short, hypersonics help fill the current gap in military capabilities against the DPRK.

Nuclear Risks

Despite these advantages, hypersonics may exacerbate the North Korean nuclear security dilemma. Even if the ROK does not intend to build nuclear-armed hypersonic weapons like China or Russia, the reality is that conventional applications of hypersonic technologies are likely to have the greatest impact on regional defense dynamics.^[14] The three foremost areas of concern revolve around the weapon’s nuclear “ambiguities,” possible AI flash wars, and the threat of a new hypersonic arms race with the DPRK.

The fast, unpredictable nature of these missiles heightens the risk of miscalculation and may spark a series of destabilizing escalatory steps, potentially leading to nuclear war. The reduced reaction time to mere minutes may lead to uncertainty about whether incoming missiles are armed with conventional or nuclear warheads.^[15] This “warhead ambiguity” makes it challenging to assess the severity of the threat and prepare a proportional response, hence increasing the likelihood of nuclear entanglement––mischaracterizing a non-nuclear hypersonic missile for a nuclear one.^[16] For instance, it would take only seconds for a conventional hypersonic weapon to fly from Seoul to Pyongyang, potentially leading the targeted nation to assume the worst and launch its own attacks. Absent advanced detection technologies, the DPRK may have difficulty determining the instigator and nature of the approaching missiles, placing the ROK and United States at risk.^[17]

The growing incorporation of emerging AI technologies further amplifies the mounting risk of unintended nuclear escalation. Open-source reports indicate that both the ROK and DPRK have already initiated the development of AI-enhanced platforms, specifically the integration of machine learning into military capabilities.^[18] Even though such automated programs are only in their nascent stages, the deployment of hypersonics will likely expedite the application of AI software to early-warning and command-and-control systems.^[19] Militaries will progressively rely on AI to overcome the critical challenges arising from hypersonic speed, nuclear entanglement, and the probability of human error.^[20] On the one hand, well-programmed machines may help avert inadvertence owing to the unpredictable qualities of hypersonic missiles.^[21] Yet analysts also note that this same unpredictability can prove detrimental to automated systems: algorithmic learning limitations may impede machines from adapting promptly to new, dynamic situations that depart from training models.^[22] The convergence of hypersonics and AI could therefore prove a catastrophic combination where the misinterpretation of signals and loss of human control may weaken crisis stability and erupt into a “flash war.”^[23]

Seoul’s decision to develop hypersonic missiles may not only inflame the extant arms competition with Pyongyang but may incite the North to build their own hypersonic weapons­­.^[24] Seoul’s entry into the hypersonic arms race should be concerning when considering the military postures of the two Koreas as well as ongoing North Korean provocations. The ROK’s growing investment in hypersonic vehicles and other missile technologies suggests an offensive military strategy that emphasizes intimidation and deterrence of the DPRK. Likewise, Kim Jong-un appears adamant in advancing and diversifying the regime’s WMD arsenal.^[25] According to reports, the North Korean Academy of National Defense Science recently established the Hypersonic Rocket Research Center, demonstrating intentions to test and deploy hypersonic weapons in the future.^[26] The DPRK’s pursuit of hypersonic missiles would increase the capability of its nuclear program, lowering the nuclear threshold and threatening the security of its regional neighbors including the ROK, Japan, and even the United States. The acquisition and development of hypersonics on the Korean peninsula may push the DPRK into adopting an escalatory, first-strike nuclear strategy, increasing the risks of crisis instability and raising the odds of military conflict.

Conclusion

Although hypersonic missiles unlock new strategic options for Seoul, they also present risks that are inimical to regional and global nuclear stability. Before the hypersonic competition devolves into another arms race, policymakers should begin the formulation of nonproliferation and arms control frameworks to match the accelerating pace of hypersonic weapons development. Early reflection and restraint are necessary to curb the deleterious effects hypersonics may have on nuclear security in the Korean peninsula the Asia-Pacific region, and the world at large. We cannot allow hypersonic technologies to grow unabated in today’s increasingly turbulent geopolitical climate.

About the Author

Katie Yoon is a former APLN Research Intern.

Disclaimer: The opinions articulated above represent the views of the author(s) and do not necessarily reflect the position of the Asia Pacific Leadership Network or any of its members. The APLN’s website is a source of authoritative research and analysis and serves as a platform for debate and discussion among our senior network members, experts and practitioners, as well as the next generation of policymakers, analysts and advocates. Comments and responses can be emailed to apln@apln.network.

Image: Pixabay stock.

Notes

1. Shin Kyu-jin, “정경두 ‘극초음속 미사일 기술개발 가속’ [Jeong Kyeong-Doo, ‘Accelerated Development of Hypersonic Missile Technologies’],” Dong-A Ilbo, August 6, 2020, www.donga.com/news/Politics/article/all/ 20200806/102319457/1.
2. Stated by President Moon Jae-in upon the lifting of fuel restrictions for missiles earlier this year. View Lee Chi-dong, “Moon urges continued efforts for ‘complete missile sovereignty,’” Yonhap News Agency, July 29, 2020, en.yna.co.kr/view/ AEN20200729006100315.
3. Richard H. Speier et al., Hypersonic Missile Nonproliferation: Hindering the Spread of a New Class of Weapons (Santa Monica, CA: RAND Corporation, 2017), xii.
4. Richard H. Speier et al., Hypersonic Missile Nonproliferation; Sander Ruben Aarten, “The Impact of Hypersonic Missiles on Strategic Stability,” Militaire Spectator, April 21, 2020, www.militairespectator.nl/thema/strategie/artikel/ impact-hypersonic-missiles-strategic-stability.
5. Ibid.
6. No Jiwon, “‘한국형 3축체계’ 명칭, 역사속으로 사라진다 [The Name ‘Korean 3-Axis System’ Disappears Into History,’” The Hankyoreh, January 10, 2020, www.hani.co.kr/arti/ politics/ defense/877873.html.
7. Ibid.
8. Ibid.
9. Song Sang-Ho, “S. Korea Renames ‘Three-Axis’ Defense System Amid Peace Efforts,” Yonhap News Agency, January 10, 2019, en.yna.co.kr/view/AEN20190110014000315.
10. Ibid.
11. In-Taek Hyun, “An Enduring Dilemma on the Korean Peninsula; Threat Perception, Perceived National Capability and Nuclear Proliferation,” The Korea Journal of Defense Analysis 28, no. 2 (June 2016): 163-180.
12. Hyung Hyuk-gyu, 극초음속 무기체계 국제개발동향과 군사안보적 함의 [International Trend of Hypersonic Weapon Systems Development and Implications for Military Security], (Seoul: National Assembly Research Service, 2020).
13. Joshua H. Pollock and Minji Kim, “South Korea’s Missile Forces and The Emergence Of Triangular Strategic (In)stability,” The Nonproliferation Review (September 2020), Taylor & Francis Online.
14. John T. Watts, Primer on Hypersonic Weapons in the Indo-Pacific Region, Atlantic Council, August 17, 2020, www.atlanticcouncil.org/wp-content/uploads/2020/08/Hypersonics- Weapons-Primer-Report.pdf.
15. Michael T. Kare, “An ‘Arms Race in Speed’: Hypersonic Weapons and the Changing Calculus of Battle,” Arms Control Association, June 2019, www.armscontrol.org/act/2019-06/ features/arms-race-speed-hypersonic-weapons- changing-calculus-battle.
16. James M. Acton, “Technology, Doctrine And The Risk Of Nuclear War,” in Nina Tannenwald et. al, Meeting the Challenges of the New Nuclear Age: Emerging Risks and Declining Norms in the Age of Technological Innovation and Changing Nuclear Doctrines (Cambridge, MA: Carnegie Endowment for International Peace, 2018), 32; James M. Acton, “Escalation through Entanglement: How the Vulnerability of Command-and-Control Systems Raises the Risks of an Inadvertent Nuclear War,” International Security 43, no. 1 (August 2018), 56-99.
17. See for more information on nuclear entanglement and target ambiguity James M. Acton, Silver Bullet? Asking the Right Questions About Conventional Prompt Global Strike, (Cambridge, MA: Carnegie Endowment for International Peace, 2013); Matteo Frigoli, “The Implications of the Advent of Hypersonic Weapon Systems for Strategic Stability,” British Pugwash, December 17, 2019, britishpugwash.org/wp-content/uploads/2019/12/M.Frigoli-Hypersonics-Stability-and -arms-control-PDF-2.pdf
18. The Impact of Artificial Intelligence on Strategic Stability and Nuclear Risk Volume II: East Asian Perspectives, ed. Lora Saalman, (Solna, Sweden: Stockholm International Peace Research Institute, 2019).
19. Sander Ruben Aarten, “The Impact of Hypersonic Missiles”; Edward Geist and Andrew J. Lohn, “How Might Artificial Intelligence Affect the Risk of Nuclear War?” RAND Corporation, 2018, www.rand.org/content/dam/rand/pubs/perspectives/PE200/PE296/ RAND_PE296.pdf.
20. Ibid.
21. Ibid.
22. Paul Scharre, “A Million Mistakes a Second,” Foreign Policy, September 12, 2018, foreignpolicy.com/2018/09/12/ a-million-mistakes-a-second-future-of-war/.
23. Paul Scharre, Army of None: Autonomous Weapons and the Future of War (New York: W.W. Norton, 2018), 229.
24. Read for greater context on the arms race between North and South Korea Edward A. Olsen, “The Arms Race on the Korean Peninsula,” Asian Survey 26, no. 8 (August 2018), 851-867; Jun Sik Bae, “An Empirical Analysis of the Arms Race Between South and North Korea,” Defence and Peace Economics 15, no. 4 (2003), 379-392.
25. This is evidenced by how North Korea recently boasted a range of new weapons technologies. See for more details Oh Seok-min, “N. Korea showcases new intercontinental ballistic missile (ICBM) during military parade,” Yonhap News Agency, October 10, 2020, en.yna.co.kr/view/AEN20201010003951325; “North Korea’s New ICBM ‘Built with Latest Missile Technologies,’” The Korea Times, October 11, 2020, www.koreatimes.co.kr/www/ nation/2020/10/ 103_297379.html.
26. Jeong Tae Joo, “North Korea forms new research center focused on ‘hypersonic missiles,’” Daily NK, January 6, 2020, www.dailynk.com/english/north-korea-forms-new-research-center-focused-on-hypersonic-missiles/.