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Aug 21, 2023

Pyongyang and Its Nuclear Weapons Programme

A Credible Threat?
Kim Jong Un
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North Korea’s nuclear capabilities are catching up with its doctrine. Setting out how to fight nuclear war is one thing, having the means to do so yet (fortunately) another.


North Korea’s nuclear capabilities are catching up with its doctrine. Setting out how to fight nuclear war is one thing, having the means to do so yet (fortunately) another. Pyongyang communicates a strategy of assured asymmetric escalation through its nuclear law and high-level political statements. Its missile programme seeks to establish the capabilities to implement this strategy, turning a declaratory doctrine into an actual nuclear posture that aligns weapon systems with mission goals and employment procedures. Notably, this doctrine and posture emphasizes strike capabilities, barely featuring defensive capabilities. Building and showcasing such a nuclear force posture aims to communicate that the threat of North Korea’s nuclear weapons is credible, which is fundamental for its nuclear deterrence strategy.

Refining its Nuclear Strategy

Nuclear threats coming from Pyongyang have long been very blunt. Over the past two decades, North Korea’s state media has carried a variety of statements with crude threats communicating a message of escalation. In past few years, however, authoritative texts have built more nuance into Pyongyang’s bombastic rhetoric. High-level statements, reports about its test-events, and its nuclear law communicate its nuclear doctrine and clarify when and how North Korea would employ its nuclear weapons.

Escalation is built into its conditions for launching nuclear weapons: North Korea has repeatedly and clearly stated that it would launch nuclear strikes if attack is imminent or underway. While state media texts have long threatened “preemption”, the 2022-updated nuclear law clarifies the forms of imminent or underway attack that Pyongyang would meet with nuclear strikes: an attack on the country with nuclear or other weapons of mass destruction as well as an attack on its leadership, nuclear command structure or other strategic objects. North Korea’s nuclear doctrine rests on using nuclear weapons (very) early in a conflict and escalating asymmetrically from a conventional to a nuclear level of warfighting.

In addition to nuclear escalation, Pyongyang threatens to expand its nuclear war from the Korean Peninsula to Japan and US islands in the Pacific if not to the US mainland. US and its allies’ military bases, command structures and capitals are potential targets for nuclear strikes. High-level statements suggest either immediate all-out regional escalation or two-phased regional escalation, the latter holding the US mainland hostage. North Korea’s doctrine of asymmetric escalation is thus twofold, nuclear and regional.

Notable has been Pyongyang’s explicit consideration of contingencies if its supreme leadership and default launch authority is decapitated or impeded: the 2022 nuclear law suggests pre-determined launch orders to be in place which would take effect “automatically and immediately” in given contingencies. State media reports about “tactical nuke drills” such as in March 2023 referenced the presence of “the combined unit chief in charge of commanding all the tactical nuclear operation units”. North Korea thereby aims to signal that asymmetric escalation is certain.

Building Nuclear Capabilities for Asymmetric Escalation

The missile testing spree since late 2019 showcases that North Korea is developing a diverse arsenal of nuclear-capable missile systems, including different basing and launch modes that involve silos and road-mobile, rail-mobilelakebed and sea surface launch platforms – even unmanned underwater vehicles. This diversity might itself increase the survivability of Pyongyang’s nuclear forces, making it more difficult to discover storage and launch sites as well as impeding early detection and warning. Importantly, North Korea is building the missile capabilities it needs to implement its nuclear strategy and turn its doctrine of assured asymmetric escalation into a credible nuclear force posture.

With regard to rapid nuclear escalation across the Korean Peninsula, Pyongyang has shifted focus from liquid-fueled to solid-fueled missile systems (i.e. KN-24, KN-25) in order to take advantage of their road-mobility. Some of these short-range ballistic missiles (SRBM) fly on quasi-ballistic trajectories (i.e. KN-23), making tracking and interception by missile defense systems more complicated. This quality also applies to North Korea’s SRBMs with maneuverable re-entry vehicles (KN-18) and its Hwasal cruise missiles. The explicit drills with “tactical nukes” in October 2022 and March 2023 sought to underscore that Pyongyang has its fleet of nuclear-capable SRBMs and cruise missiles deployed and ready.

As regards the plans for regional escalation, Pyongyang has developed at least six different theatre-range systems. These include road-mobile liquid-fueled systems capable of targeting US strategic bases on Guam (Hwasong-12) as well as solid-fueled systems capable of being launched from underwater and threatening bases in Japan (Pukguksong-3). North Korea has also tested boost-glide vehicles and maneuverable re-entry vehicles on shortened versions of its intermediate-range ballistic missile Hwasong-12, likely in pursuit of challenging enemy’s tracking and interception.

Most notable is Pyongyang’s success in developing at least four different road-mobile intercontinental ballistic missiles (ICBM) for nuclear strikes against the US mainland. The liquid-fueled Hwasong-15 and Hwasong-17 might be deployed while solid-fueled Hwasong-18 might be close to deployment. Hwasong-17 and Hwasong-18 could be capable of carrying multiple nuclear warheads rendering interception more difficult.

Missing Pieces

All of this is impressive and unsettling, particularly the diversity and speed of developments. A few questions and missing pieces remain in place for now, but their relevance might become secondary if technical progress accelerated and Pyongyang turned more risk-acceptant.

Analysts question the accuracy and reliability of the above-mentioned missile systems, particularly North Korea’s ICBMs and their re-entry vehicles. Pyongyang has threatened, but refrained so far from flight-testing their ICBMs on other than highly lofted trajectories. Doing so would stress-test the re-entry of the ICBM’s payload as well as increase the risk of escalation if countries in the Pacific are affected by falling debris.

North Korea has already threatened to use the Pacific Ocean as a testing ground, when its then-foreign minister mentioned to reporters in 2017 the possibility of an atmospheric nuclear test. Pyongyang conducted its last nuclear test underground in September 2017 even if satellite imagery has shown restored a testing tunnel since March 2023 and its nuclear engineers might want to test a lower-yield nuclear warhead for its “tactical nukes”.

There are at least two missing pieces to complete North Korea’s above-mentioned nuclear doctrine and posture of assured asymmetric escalation: a submarine capable of launching ballistic missiles and capabilities for intelligence, surveillance and reconnaissance (ISR). Pyongyang has launched a number of short- to medium-range ballistic missiles from sea surface or underwater platforms. These missile capabilities add to general diversity but would be particularly survivable if deployed in submarines at sea. The relevant submarine, however, seems to be still in development and was last showcased in 2019. Furthermore, ISR capabilities present the more crucial missing piece since launching nuclear strikes in response to an attack that is imminent or underway requires reliable and real-time information about adversaries’ activities. Kim Jong Un emphasized the ambition of putting military reconnaissance satellites into orbit in 2021 and 2023, but – even though the new satellite launch vehicle is notable – it’s a long way to operating the needed and proclaimed network of ISR satellites.

In January 2021, Kim Jong Un laid out the current five-year plan to build his country’s nuclear posture, all fitting to its doctrine of assured asymmetric escalation. We are at the half-way point and recent missile developments check many of boxes already. There is time for North Korea to make good on the two missing pieces – or at least present itself as doing so.

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This article has first been published by ISPI on August 4, 2023.

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