Introduction

After a hiatus of almost 18 months, in May 2019, North Korea resumed ballistic missile launches. Although abiding by its self-imposed moratorium on launching intercontinental and intermediate-range ballistic missiles (ICBMs and IRBMs), the DPRK has thus far conducted the initial launches of at least three new types of solid-propellant, short-range ballistic missiles (SRBMs). Despite the relatively short time since these launches began and the very limited information available on these systems so far, much of the coverage in the Western media has portrayed these new systems as having “significantly raised the country’s [DPRK’s] military capabilities,” as “a marked improvement” in the North Korean missile threat to South Korea and Japan[1] (including to US forces there)—and even an “immense danger.” These fears are overblown. The launches of new SRBMs over past four months do not fundamentally change the balance of power on the Korean Peninsula and are highly unlikely to embolden Kim Jong Un to act more aggressively against the US or its allies in Northeast Asia. The deterrence that has prevented armed conflict on the Korean Peninsula for decades is as much of a reality today as it was a week, a year or five years ago. Concerns about these missiles resulting in a possible decoupling of the US-ROK alliance are unfounded.

Assessment of SRBM Developments

The launch of new SRBMs over the past four months totaled:

seven launches on May 4 (one launch) and 9 (two launches), July 25 (two launches), and August 6 (two launches) of the KN-23, which externally resembles the Russian Iskander SRBM;

four launches on July 31 and August 2 (two launches each) of a “large-caliber multiple launch guided rocket system,”[2] actually a ballistic missile; and

four launches on August 10 and 16 (two launches each) of a system that externally resembles an enlarged version of the US Army Tactical Missile System (ATACMS).

Two more SRBMs were launched to a range of 380 km on August 24. North Korea termed these “super-large multiple rocket[s],” and provided photographs showing what may be yet a fourth new type of missile system.

Western media coverage has mostly assessed the threat from the three new SRBM systems based on four broad military-technical attributes: (1) missile system survivability, as a function of mobility and of the much faster reaction time of solid-propellant compared to liquid-propellant systems; (2) ability to penetrate missile defenses; (3) accuracy; and (4) dual capability. Taking these attributes together, the media generally has stressed that the three systems pose a new, sophisticated and significant threat to South Korea, Japan and US forces there.

Survivability

The fact that all three new systems use solid propellants and are mounted on mobile launchers is depicted in the Western media as making them substantially more survivable than the liquid-propellant missiles that make up the bulk of North Korea’s current SRBM force. One report even claimed these systems were “designed to circumvent preemptive strikes” by the US and South Korea. However, neither mobile nor solid-propellant SRBMs are new in the DPRK. All of North Korea’s deployed SRBMs have always been deployed on mobile launchers, including the several variants of liquid-propellant Scuds the DPRK has been fielding since about 1986, as well as the solid-propellant 120-to-170 km range KN-02/Toksa SRBMs that North Korea has deployed since 2006-2008 (if not earlier).

Much has been made in the media coverage of the fact that solid-propellant systems do not have to be fueled prior to launch, and have a faster reaction time than liquids. But although some media coverage suggests liquids must sit out in the open just prior to launch to be fueled, thus providing substantial time and opportunity for their destruction during crisis or wartime, North Korean Scud launchers would almost certainly have been dispersed from base carrying fueled missiles. The most important contribution of solid-propellant mobile missiles to survivability probably stems from their ability to operate in the field without needing propellant storage and handling vehicles, reducing their footprint and, thus, their detectability.

Although solid-propellant SRBMs still can react more quickly than liquid-propellant SRBMs, the use of already-fueled liquid-propellant missiles in crisis or wartime cuts down much of the difference. Iraq showed in the 1990-1991 Gulf War that it could launch already-fueled Scuds within 30 minutes of arriving at a new launch site, and have the launchers immediately depart to alternate concealment sites (“shoot and scoot”). Iraq’s ability during 1990-1991 to preserve most (if not all) of its mobile Scud launchers using such tactics in the face of coalition air superiority and a dedicated “Scud-hunting” effort—and in desert terrain, to boot—underscores the substantial survivability benefits even liquid-propellant mobile SRBMs enjoy if competently operated by the DPRK.

Ability to Penetrate Missile Defenses

Western media coverage has rightly focused on features in all three new SRBMs that will further complicate the task of US and ROK missile defenses:

the apparent trajectory-changing capability demonstrated in launches of the KN-23;

the demonstration of 48 km apogees by the KN-23 and the ATACMS-like system, above the 40 km maximum engagement altitude of the Patriot and below the 50 km minimum engagement altitude of the THAAD and Aegis missile defense systems; and

the potential for guidance throughout flight (and, therefore, an unpredictable flight path).

One analyst even contends that the defense-avoidance features of the KN-23 represent “…an alarming evolution in North Korea’s strategic thinking…beyond rudimentary forces that could retaliate for an attack or attempt to prevent U.S. reinforcements from arriving on the peninsula in a major war,” toward “a first strike option to destroy stealth aircraft on the ground before they have a chance to take off, or potentially to destroy the command and control networks that coordinate military operations.”

North Korea can, however, already operate its existing SRBM force in ways that would complicate allied missile defense efforts; for example, it can conduct saturation attacks to overwhelm the number of interceptors that can be launched and guided at one time, and defense-suppression attacks against the radars and other key nodes of the missile defense system. The existing “rudimentary” force would be quite capable of executing the kind of first strike option attributed uniquely to the KN-23. Moreover, North Korea flight tested three times in 2017 (twice apparently successfully) a maneuvering reentry vehicle (MaRV) payload for the Scud that also would have an unpredictable flight path.[3] But the new SRBM systems, if deployed in sufficient numbers, will give the DPRK more options to evade and attack allied missile defenses, and probably will reduce the number of SRBMs North Korea would need to expend in defense suppression/saturation missions (making more available for other targets).

Accuracy

High accuracy allows ballistic missiles to have greater lethality with conventional warheads. Media coverage has depicted the three systems as more accurate than existing DPRK SRBMs. This is a reasonable assumption when comparing inertially guided DPRK Scud SRBMs to the KN-23 (given the latter’s resemblance to the relatively accurate Russian Iskander) and the “multiple launch guided rocket system” (given its shorter range, and, thus, shorter opportunity for inertial guidance system drift, and the presence of nose-mounted canards, suggesting in-flight guidance). There is less of a basis for such an assumption in the case of the ATACMS-like system, which has no obvious visual indicator of terminal or satellite-aided guidance—although, of course, these cannot be ruled out, either.

For all three new systems, it is important to point out that we do not yet know from open-source data how they are guided, how capable their guidance systems are or what accuracy they have actually demonstrated. Also, the current DPRK SRBM force does not just contain inertially guided Scuds: the long-deployed KN-02/Toksa may use an optical correlation system to supplement its guidance, and as noted above, the DPRK may already have deployed a MaRV on some of its Scuds that might be as accurate as the new systems (although, this, too, is unknown).

Dual Capability

Some media reports have noted that the KN-23, and perhaps the ATACMS-like system, can carry either nuclear or conventional warheads. A few of these reports have claimed this will create a “new level of unpredictability,” because the US and ROK would not be able to tell if an incoming missile was nuclear and thus would have “a matter of seconds” to determine how to respond. This, in turn, reputedly would tempt both the Allies and the DPRK to launch their missiles before the other side could.

This scenario, however, is much more reflective of the US and USSR during the Cold War than it is of the situation on the Korean Peninsula. The North probably believes a war would be preceded by an identifiable and relatively lengthy period of tension. Both sides almost certainly expect a conflict to begin with the use of conventional weapons, and probably to continue conventionally for a substantial period. North Korea has long had the option to initiate a war (or initiate escalation during a conventional war) with nuclear-armed SRBMs, but the US and ROK appear to have relied on the threat of retaliation by America’s massive, survivable nuclear capabilities deployed off-shore to deter such a move rather than to hold forces on the peninsula on a hair trigger to launch before the DPRK can (which still might not prevent a DPRK nuclear strike).

In sum, the true contribution of the three new SRBM systems to the DPRK missile threat will depend most heavily on how many launchers and missiles of each type are deployed, and how accurate the new systems turn out to be. Both of these factors currently are unknown. If the new systems are substantially more accurate than existing DPRK SRBMs and are deployed in significant numbers, rather than constituting an “immense danger,” they will add incrementally to the longstanding SRBM threat that ROK and US forces have faced for over 25 years. In particular, they would allow North Korea to subject more US and ROK targets to SRBM attack (particularly more point targets), add to the intensity of attacks, increase the North’s opportunities to tailor particular attacks to particular missile systems and further complicate the task of US and ROK missile defenses.

Context Matters: Why Now?

Just as US officials must scrutinize the technical aspects of the SRBM launches, they would also be wise to take the broader context of these missile tests into account. The Kim regime has made it abundantly clear over the past two months that it would respond to the joint US-ROK 19-2 Dong Maeng joint military exercises. In late June, over a month before the drills commenced, North Korean foreign ministry officials warned Washington and Seoul about proceeding. The Kim regime’s interpretation of the US-ROK exercises remained consistent throughout: Such behavior is a deliberate act of hostility inconsistent with the Panmunjom and Pyongyang communiqués signed in 2018, both of which emphasized a de-escalation of military hostilities between the two Koreas and the establishment of a comprehensive inter-Korean dialogue. As the drills began, the tone of the North’s rhetoric became more brazen and less compromising. Pyongyang threatened to rescind its moratorium on nuclear and long-range missile tests and linked a resumption of denuclearization negotiations to the Moon administration showing contrition for its participation in the military exercises. South Korea’s acquisition in July of the F-35 fighter provided the North with an additional reason to proceed with SRBM testing.

The spate of missile launches by the North should not have been a surprise, therefore, to US and South Korean officials. An August 6 statement from the North Korean Ministry of Foreign Affairs bluntly stated that Washington and Seoul’s military exercises compelled “the DPRK to take countermeasures for eliminating the potential and direct threats to its state security.” From North Korea’s perspective, a tit-for-tat response to the US-ROK drills with military drills of its own was not only an appropriate response to an undiplomatic act, but also a way to send a stern message that Pyongyang will not be intimidated. For the North, the May-August missile launches were as much about demonstrating resolve and toughness in the face of adversity as they were about enhancing the range, accuracy and survivability of its SRBM fleet.

Taking the Long-View: Deterrence Is Still Alive and Well

Although there is a lot of technical information we don’t yet know about the new SRBM systems, North Korea’s military posture vis-à-vis the combined strength of the US-ROK alliance remains relatively static. With or without the new SRBMs, the ROK was already under the shadow of thousands of North Korean missile, rocket, mortar and artillery systems, all of which have proven to be a sufficient deterrent against a theoretical US or South Korean military attack. The Kim regime’s Hwasong-5 and Hwasong-6 (Scud-B/C) SRBMs have long possessed the range to reach the South Korean capital and the rest of the country with relative ease. The regime’s larger quantity of 150-170 mm self-propelled howitzers and 200-240 mm multiple rocket launchers just north of the Demilitarized Zone could already cause extreme damage to Seoul and tens of thousands of casualties in the event of a conflict, devastation that has dissuaded Washington and Seoul in the past from embracing a more aggressive strategy. The greater Seoul area—where approximately 50 percent of South Korea’s population lives—is effectively already held hostage to older North Korean conventional weaponry. The potential advent of the new SRBM systems does not add much to the overall threat picture, or add “a significant challenge to the deterrence posture of the U.S.-South Korean alliance.”

Some analysts are increasingly concerned about the possible decoupling of the US-ROK alliance in light of the North’s improved SRBM capability. The theory is straightforward: the more durable and accurate North Korea’s SRBM inventory, the less likely the United States will defend the South (or Japan) in the event of a conflict. US President Trump’s nonchalant dismissal of the North’s SRBM tests as less significant than longer-range IRBM or ICBM launches has done nothing to assuage South Korean and Japanese worries about the United States’ commitment to come to their defense against a North Korean attack. Some analysts have suggested that Trump’s constant downplaying of North Korean SRBM launches has the potential to irreparably harm America’s reputation as a reliable ally over the long-term. Such alliance decoupling would presumably heighten Pyongyang’s willingness to embrace a more confrontational strategy toward both Seoul and Tokyo.

However, this concern is vastly overstated and based more on emotion than cold-hearted analysis. First, the North Koreans cannot be sure how their SRBM capability will hold up during a prospective conflict. Testing and exercises are one thing, but real-life scenarios where US and ROK missile defense and counter-strike systems are fully prepared for operations is something else entirely; it is a safe assumption that a portion of these missiles are likely to be rendered ineffective by these allied capabilities. Kim is unlikely to stake the survival of his regime on such an SRBM program. Indeed, the very concept of alliance decoupling is at best dubious—with over 28,000 US military personnel stationed on South Korean soil and tens of thousands of additional American civilians residing in Seoul alone, a North Korean attack utilizing any weapon is bound to result in American casualties and, would thus almost certainly prompt a fierce US military response.

Conclusion

The multiple SRBM launches since May 2019 are cause for concern, but their impact on the general strategic environment should not be overstated. Despite claims of technological progress from the North, there are a lot of technical details related to these new missile types that are unknown, including deployment numbers, accuracy and actual effectiveness against US and ROK missile defenses. While it is reasonable to assess that these new systems will allow North Korea to increase the number of potential targets in South Korea subject to SRBM attack, South Korea and the US forces deployed there have lived under the North’s SRBM threat for decades. Kim Jong Un’s eagerness to take risks on the Korean Peninsula is unlikely to change, even if his missile program has improved incrementally. There is no evidence to suggest that the latest missile flight tests have persuaded him to adopt a more aggressive posture—particularly when such a course of action could put his own survival in severe jeopardy. Kim’s instinct for self-preservation and the US military response that would almost certainly occur in the event of a North Korean attack of any kind will continue to restrain him from taking reckless action.