Missile Deployments on the Korean Peninsula: An Accelerating Arms Race

(Source: Rodong Sinmun)

South Korea’s significant improvements in its conventional force capabilities are an important driver of North Korean efforts to accelerate its development of more advanced ballistic missile and nuclear weapons capabilities. The North’s incorporation of new technologies into its ballistic missiles will significantly increase the threat to South Korean and US national security. The Biden administration’s announcement that it will seek a pragmatic and phased approach to North Korean denuclearization could give Pyongyang incentives to reach agreements favorable to Washington and Seoul. These future negotiations could curb the North’s further missile development and stop or decelerate the arms race underway between the two Koreas, while creating opportunities to build the kind of confidence needed to continue working toward denuclearization.


North Korea conducted two short-range missile tests at the end of March—the first such tests in a year and the first since US President Joseph Biden took office. Just before the tests, First Vice Foreign Minister Choe Son Hui said North Korea felt no need to respond to the recent attempts by the Biden administration to establish dialogue, dismissing them as a “delaying-time trick.”[1] Kim Jong Un has probably judged that, at least in the near term, Biden is not interested in meeting the regime’s major demands, such as an end to America’s “hostile policy” and security guarantees and sanctions relief for the North. From the regime’s perspective, reaching a nuclear deal now with the new administration seems less likely than it was during the Trump presidency, as Biden has already placed emphasis on the threat North Korea poses and its human rights record.

As a result, the missile tests conducted in late March were seen as a signal to Washington that Pyongyang would continue developing its nuclear weapons program in the current “hostile” environment. Ri Pyong Chol, vice chairman of the Central Committee of the Workers’ Party of Korea, made a statement proclaiming that North Korea is solely exercising its right to self-defense and condemned the unfairness of the security situation on the peninsula by stating the US brought “strategic nuclear assets into the Korean Peninsula and launch[es] ICBMs [intercontinental ballistic missiles] any time it wants,” and criticizes “the North when it conducts ‘even a test of a tactical weapon.’”[2] On March 28, Jo Chol Su, a senior foreign ministry official, similarly described the test as “an exercise of the righteous self-defensive right to deter military threats posed to the Korean Peninsula and safeguard peace and prosperity of our state.”[3]

Missile Race With South Korea

In many ways, North Korea’s most recent missile advancements have focused on capabilities to counter South Korean defense improvements, including ballistic missile capabilities and missile defenses. Despite the protection of US extended deterrence, over the next five years, the South Korean government plans to spend more than 80 percent of its $90 billion defense budget to boost defense capabilities, especially its missile defenses. Meanwhile, the US agreed to lift weight limits for South Korean ballistic missiles in 2017, “leading to the development of at least one heavier weapon that could play a key role” in implementing “strategies aimed at preempting North Korean attacks or ‘decapitating’ its leadership.” One of the significant outcomes is the Hyunmoo-4 missile with a range of 800 km and a warhead weight of two tons. This missile can be used to strike deeply buried underground facilities in North Korea.

Another big part of South Korea’s recent missile development is a new submarine-launched ballistic missile (SLBM), the Hyunmoo-2B; these conventional missiles, with a 500-km range, are expected to be deployed with the 3,000-ton class KSS III or larger submarines. South Korea’s SLBM development and latest flight test may have been a potential motivation for North Korea’s new Pukguksong models, shown at recent military parades.

In a speech at the Eighth Party Congress in January, Kim Jong Un criticized South Korean President Moon for remarks made on a visit to the state-run Agency for Defense Development (ADD), where he proclaimed that the country’s ballistic missile development had “sufficient range and the world’s largest warhead weight,” most likely referring to the Hyunmoo-4.[4] These developments show an emerging arms race between the two Koreas, as both Seoul and Pyongyang work to match each other’s military advancements.

However, North Korea is focusing on developing offensive missiles to deter South Korea’s military strength because it has no missile defense system to ensure the survivability and second-strike potential of its strategic arsenal. Thus, its recent tests were intended to demonstrate a missile attack capability surpassing South Korea’s Hyunmoo-4 in terms of the sophistication of its guidance system and warhead weight. For instance, North Korea’s Korean Central News Agency (KCNA) reported that the new missiles could carry a payload of 2.5 tons—more than double the weight of its KN-23’s one-ton warhead.[5] In theory, the new ballistic missile would be capable of carrying a heavier warhead than South Korean missiles, which maxes out at two tons.

KCNA also claimed that the missiles were solid-fuel tactical and carried a “new-type tactical guided projectile” that could perform “gliding and pull-up” maneuvers in low-altitude flight.[6] This advancement could render useless the Terminal High Altitude Area Defense (THAAD) system deployed in South Korea in 2017. North Korea also announced that the two missiles flew 600 kilometers toward the East Sea (Sea of Japan), while the South Korean military estimated a flight distance of around 450 kilometers with an altitude of 60 kilometers. Some missile experts suggest “gliding and pull-up” maneuvers would enable the missiles to avoid radar detection systems in South Korea, creating new challenges for its missile defenses. In addition to the development of short-range ballistic missiles (SRBMs), Pyongyang has reportedly announced plans to deploy nuclear-powered submarines armed with nuclear weapons by 2022, and has said that they would carry the Pukguksong-5, the country’s most recently revealed (but not yet flight tested) SLBM. Kim Jong Un has said that such a weapon will be of great importance in raising North Korea’s surprise attack and long-range nuclear strike capabilities.[7]

The Race Between Offense and Defense

US missile defense systems have also been evolving to deal with North Korea’s nuclear and missile threats. In March 2020, the Trump administration asked the US Congress to provide “$380 million over the next five years” to develop and test a “prototype space-based laser weapon” by 2023 that can destroy ICBMs. On November 16, 2020, the US Navy successfully launched the SM-3 Block IIA from Kwajalein Atoll toward an area northeast of Hawaii—a missile designed to eliminate an incoming “ICBM-representative target,” such as North Korea’s ICBMs.

North Korea’s new class of SRBMs currently poses a serious threat to South Korean and American troops on the Korean Peninsula—a threat that will grow as Pyongyang fields SRBMs with solid-fuel engines, hypersonic missiles and maneuverable warheads. During the Eighth Party Congress, Kim Jong Un said North Korea is “conducting research into perfecting the guidance technology for multi-warhead rocket[s] at the final stage.”[8] Based on North Korean ICBM development and testing to date, its new ICBM might have sufficient payload to allow the deployment of multiple, independently targetable warheads; further North Korean progress in warhead miniaturization could enable it to deploy four multiple warheads for its ICBMs by 2022. If these technologies are fielded, the North’s missiles will be less vulnerable to missile defenses. North Korea is, therefore, increasingly likely to accelerate strategic weapons testing in the years ahead to make those improvements. However, in order to avoid additional sanctions and external military pressures as much as possible, Pyongyang appears to be taking partial and gradual steps to obtain the necessary know-how and technologies for a new ICBM, rather than conducting additional tests of the long-range missile.


South Korea’s significant improvements in its conventional force capabilities have driven North Korea to advance its strategic weapons and nuclear capability. What we are witnessing today on the Korean Peninsula is the same kind of action-reaction dynamic that developed between the United States and the Soviet Union during the Cold War—a destabilizing and expensive arms race that prompted both sides to pursue arms control agreements to promote strategic stability, reduce arms racing, and lessen the burden of defense expenditures. North Korea might find arms control attractive because it would make it easier to pursue parallel development of its nuclear deterrent and economic growth.

  1. [1]

    “Statement of First Vice Foreign Minister of DPRK,” KCNA, March 18, 2021.

  2. [2]

    See: “Ri Pyong Chol Expresses Deep Apprehension over U.S. President’s Statement Faulting DPRK’s Regular Testfire,” KCNA, March 27, 2021; and “N.K. says Biden’s remarks on recent missile launches a ‘provocation’,” Yonhap News Agency, March 27, 2021, https://en.yna.co.kr/view/AEN20210327000800325.

  3. [3]

    “Double Standard Will Invite More Serious Consequence: Director-General of Department of International Organizations, Ministry of Foreign Affairs of DPRK,” DPRK Ministry of Foreign Affairs, March 29, 2021, http://www.mfa.gov.kp/en/double-standard-will-invite-more-serious-consequence-director-general-of-department-of-international-organizations-ministry-of-foreign-affairs-of-dprk/.

  4. [4]

    See: “조선로동당 제8차대회에서 하신 경애하는 김정은동지의 보고에 대하여,” KCNA, January 9, 2021; and “S. Korea to accelerate development of hypersonic missiles: defense chief,” Yonhap News Agency, August 5, 2020, https://en.yna.co.kr/view/AEN20200805008300325?section=search.

  5. [5]

    See: “Academy of Defence Science Test-fires New-type Tactical Guided Missiles,” KCNA, March 26, 2021; and “(News Focus) New KN-23 ballistic missile to boost N. Korea’s tactical nuclear capabilities: experts,” Yonhap News Agency, March 26, 2021, https://en.yna.co.kr/view/AEN20210326006800325.

  6. [6]

    See: “Academy of Defence Science Test-fires New-type Tactical Guided Missiles,” KCNA; and Laura Bicker, “North Korea claims ‘new tactical guided’ missiles launched,” BBC, March 26, 2021, https://www.bbc.com/news/world-asia-56533260.

  7. [7]

    “Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory On Report Made by Supreme Leader Kim Jong Un at Eighth Congress of WPK,” DPRK Ministry of Foreign Affairs, January 9, 2021, http://www.mfa.gov.kp/en/on-report-at-eighth-congress-of-wpk/.

  8. [8]

    See: “Great Programme for Struggle Leading Korean-style Socialist Construction to Fresh Victory On Report Made by Supreme Leader Kim Jong Un at Eighth Congress of WPK,” DPRK Ministry of Foreign Affairs; and Joshua Berlinger and Yoonjung Seo, “Kim Jong Un says North Korea is developing tactical nukes, new warheads and a nuclear-powered submarine,” CNN, January 9, 2021, https://edition.cnn.com/2021/01/09/asia/north-korea-nuclear-development-intl-hnk/index.html.

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