Eric Gomez analyses recent tests in the North Korean missile programme and asks what comes next

In early January 2021, at the 8th Party Congress – a landmark political event where the world’s most secretive state sets forth its goals for the next five years – a report set out by the country’s dictator Kim Jong Un underscored the importance of nuclear weapons for North Korea’s survival. It also pledged to both improve existing missile capabilities and develop new systems.

Recent missile systems displayed at military parades and high-profile political statements indicate that North Korea is pursuing improvements to both its strategic and regional missiles.

On the strategic side, Pyongyang wants to field larger liquid-fuel intercontinental-range ballistic missiles (ICBMs) capable of carrying heavier payloads than its current ICBMs. Another important strategic priority is the development of larger solid-fuel ballistic missiles.

On the regional side, North Korea’s near-term priority is to field large numbers of solid-fuel missile systems to counteract American and South Korean conventional forces. These short-range, solid-fuel missiles are probably only armed with conventional warheads for the time being, but the 8th Party Congress report mentioned tactical nuclear warheads as a top priority.

Strategic solid-fuel missiles
North Korea’s strategic missiles include intermediate-range ballistic missiles (IRBMs) and ICBMs that can reach US territory from North Korean territory. By March 2021, all these missiles used liquid fuel and were carried by transporter erector (TE) vehicles, which are capable of moving missiles to launch positions but are not capable of firing the missile from the vehicle.

North Korea tested three types of missiles in 2017 that form the core of its strategic missile arsenal—the Hwasong-12 IRBM, and Hwasong-14 and -15 ICBMs.

Test impasse
As of March 2021, North Korea has not tested a strategic missile since November 2017. While there was a successful flight test of a nuclear-capable submarine-launched ballistic missile (SLBM) in October 2019, it would have to be transported far beyond North Korea’s coasts before it could strike any US territory.

This absence of recent strategic missile tests means that analysts must depend on military parade imagery, propaganda statements, and satellite imagery to glean information about Pyongyang’s development priorities. Paraded missiles and propaganda statements are less reliable sources of information compared to flight test data, but they offer a starting point for assessing North Korea’s intentions.

On 10 October 2020, North Korea celebrated the 75th anniversary of the foundation of the Worker’s Party with a night-time military parade that featured some new strategic missile systems alongside existing capabilities. Two strategic missiles displayed for the first time at the parade are particularly noteworthy: the Pukguksong-4 SLBM and an unnamed ICBM.

The Pukguksong-4
The Pukguksong-4 stands out because it is a large solid-fuel missile, which makes it easier to transport and faster to fire than missiles that use liquid fuel. Unlike liquid rocket fuel, which tends to be loaded into the missile after it has reached its firing area, solid rocket fuel is manufactured into the body of the missile.

This cuts back on the supporting vehicles necessary to accompany the missile in the field and shortens the time between arriving at a firing area and launch, thereby making solid-fuel missiles much harder to destroy before they can be fired. While the Pukguksong-4 is not large enough to have ICBM range, it shows that North Korea is making progress toward mastering solid-fuel missile technology.

The Hwasong-16
The unnamed ICBM, commonly referred to as the ‘Hwasong-16’ by analysts, stands out because of its size. The Hwasong-16 was carried by an 11-axle TE at the parade – two axles and thus several metres longer than the Hwasong-15 ICBM – and appears to be powered by two engines compared to the Hwasong-15’s one.

While the missile’s precise dimensions and performance are unknown, its size and statements in North Korean propaganda suggest that it can carry a very heavy payload. A large payload capacity means that the Hwasong-16 will have an easier time defeating US missile defences – either by deploying multiple warheads to overwhelm defensive systems, or carrying countermeasures to trick them.

Adding solid-fuel missiles and improving the payload capacity of ICBMs are the two most pressing priorities for North Korea’s strategic missile forces. If both steps succeed, then Pyongyang will be able to significantly improve the survivability of its nuclear deterrent.

Greater protection against a disarming attack could encourage US-North Korea strategic stability in theory, but Washington is unlikely to accept mutual vulnerability. Absent a change in US policy that places greater emphasis on arms control instead of full denuclearisation, North Korea’s new strategic missile systems will likely accelerate an existing offense-defence arms race that will in turn encourage greater US missile defence spending.

Regional missiles
North Korea’s regional missiles are used to hold targets on the peninsula and in Japan at risk. Until recently, this arsenal primarily consisted of dual-capable, liquid-fuel Scud variants alongside nuclear-armed SLBMs that could fly 2,000 km. The most likely targets for this portion of North Korea’s missile arsenal are allied capitals and US military bases that would be used to conduct a war against North Korea.

North Korea did not test a single ballistic missile in 2018 as it engaged in high-level diplomacy with both South Korea and the US. Testing resumed after the failure of the US-North Korea summit at Hanoi in February 2019.

Testing spree
According to the James Martin Center for Nonproliferation Studies database of North Korean missile tests, 2019 was the most active year to date with 27 launches taking place. This rapid pace of testing seemed set to continue in 2020 until the Covid-19 pandemic reached North Korea.

Every missile that North Korea has tested since the Hanoi summit breakdown has been a solid-fuel regional system. Moreover, none of the missile designs had been tested prior to 2019. Only one of the new regional capabilities, the Pukguksong-3 SLBM, is clearly nuclear-armed.

The other three new designs, the KN-23 short-range ballistic missile (SRBM), KN-24 SRBM, and the KN-25 large-calibre multiple rocket launcher, appear to be conventional-only systems based on state media reports that excluded words and phrases commonly associated with nuclear-capable missiles. In March 2021, North Korea tested a missile that was visually similar to the KN-23 SRBM that, according to propaganda statements, was a “new-type tactical guided missile” capable of carrying a 2.5-ton payload. While the “tactical” label suggests that the missile has a conventional warhead, its payload capacity would enable it to carry a nuclear weapon.

A growing arsenal of conventional, solid-fuel SRBMs substantially improves North Korea’s ability to conduct attacks on US and South Korean military assets on the peninsula. Air force bases are an especially high-priority target due to allied advantages in numbers and quality of strike aircraft and North Korea’s relatively weak air defence capabilities.

South Korea’s acquisition of F-35 stealth aircraft is particularly threatening from Pyongyang’s perspective and will likely be one of the principal targets of the KN-23, KN-24, and KN-25.

“Smaller and lighter”
However, it is important to note that North Korea’s new short-range ballistic missiles may not stay conventional for long. Making nuclear weapons “smaller and lighter for more tactical uses” was a prominent goal in Kim’s report to the 8th Party Congress. The KN-23, KN-24, and new SRBM tested in March could probably carry tactical nuclear weapons if North Korea successfully developed them.

Moreover, tactical nuclear weapons would mark a significant and substantive change in North Korea’s nuclear forces than the heavier payload or solid-fuel ICBMs due to the difficulty of creating compact nuclear devices.

North Korea is coming into its own as a nuclear power. After successfully demonstrating a rudimentary ICBM capability in 2017, Pyongyang now seeks to improve the survivability of its strategic missile forces. North Korea is also working quickly to enhance its conventional regional missile capabilities, which could become dual-capable in the near future. The Biden administration should try to forestall these developments, but doing so without igniting a dangerous, and likely nuclear, war will require creative diplomacy.

Eric Gomez is Director of Defence Policy Studies at the Cato Institute. His research focuses on nuclear deterrence, arms control, and inadvertent escalation in East Asia.

Image: Pukguksong-4 SLBM on parade, 10 October 2020.
© Korean Central News Agency (KCNA) via Scott LaFoy