North Korea “Tactical Nuke” Drill: Claims on Command/Control and Hints of A First-ever Silo Launch

North Korean media reported that the country recently conducted a “combined tactical drill simulating a nuclear counterattack by the units for the operation of tactical nukes” on March 18-19. Coverage of the drill included new details about the North’s nuclear command and control system, which sound similar to those used in the US and USSR/Russia. While none of these details can be verified from open sources, they seem within North Korea’s capacity, given its 40+ years of experience with missiles and its apparent access to substantial Russian and Chinese missile technology.

As part of the drill, the North launched a KN-23 solid-propellant short-range ballistic missile (SRBM). Associated photos suggested the missile was launched from a silo rather than a road-mobile launcher, which would be the first time North Korea demonstrated silo basing. Subsequent imagery analysis in 38 North calls into question whether there is an actual silo at the launch location and judges the missile more likely used a road-mobile launcher. Regardless, this launch highlighted the possibility of silo basing in the future.

Adding silo-deployed missiles to the North’s longstanding road-mobile missile force may have some economic advantages, but the vulnerability and operational downsides of the former are highly likely to limit their proportion of Pyongyang’s overall missile deployments. This, in turn, limits the downsides to the alliance of any silo-based North Korean missiles.

In announcing the drill, North Korea was clearly trying to send a strong deterrent message to the US and South Korea. It also wanted to emphasize that it has a “fast, strict, highly reliable and safe system” of nuclear command and control and to underscore the capability and credibility of its “tactical nuke” threat to South Korea.

“Tactical Nuke” Counterattack Drill and Command/Control

On March 20, North Korean press announced that a “combined tactical drill simulating a nuclear counterattack by the units for the operation of tactical nukes” took place over the previous two days, culminating in a launch on March 19 of a “tactical ballistic missile” that was “tipped with a test warhead simulating a nuclear warhead.” The missile reportedly flew to a range of 800 kilometers (km) (consistent with Japanese and South Korean reports) and “accurately exploded at 800 meters above the target waters.” Accompanying photographs and still photos on North Korean TV depicted the launch and early boost phase of a KN-23 solid-propellant SRBM, which had previously flown 800 km in October 2022. (The photographs also suggested the missile may have been launched from a silo, which will be discussed in the next section.)

The press announcement referred to various elements of a nuclear command-and-control system sounding similar to systems used in the US and USSR/Russia. These included:

• a “combined unit chief in charge of commanding all the tactical nuclear operation units” with “missile units and sub-units under his command on the east and west fronts”;
• a “nuclear strike control system”;
• an “operation system for the command and management over the tactical nuclear force,” apparently including “operation procedures for implementing different nuclear attack plans,” an “order of handling nuclear weapons” (possibly related to mating a nuclear warhead to a missile), and “relevant action procedures”;
• a “launch approval system,” apparently including “procedures of issuing and receiving an order of nuclear attack” and “final nuclear attack order authentication”; and
• “technical and mechanical devices” apparently governing nuclear weapons control (possibly including Permissive Action Links [PALs] or some other means of preventing unauthorized arming or launch), including “nuclear explosion control devices and detonators fitted in the [mock] nuclear warhead.”

This is the most detail revealed by North Korea related to nuclear command and control. Its claims of using a mock nuclear warhead, detonating that warhead at an 800-meter burst height, and having a command-and-control system with these specific attributes cannot be verified from open sources. However, all of them are reasonable for the North to possess and plausible in light of Pyongyang’s 40+ years of experience with missiles and its apparent access to substantial Russian and Chinese missile technologies. The ability to detonate a nuclear warhead at a given altitude allows the attacker to optimize the desired effects on ground targets for a given nuclear yield. Altitude control also is desirable for some types of conventional and chemical/biological warheads, such as those using submunitions.

More important than the technical aspects of the March 20 statement are the political ones. North Korea clearly is trying to demonstrate what the statement calls its “tougher will to make an actual war response and send a stronger warning to the enemy” and that it has a “fast, strict, highly reliable and safe system” of nuclear command and control as befits the “fact that it is a nuclear weapons state.” The North also is continuing to underscore the capability and credibility of its “tactical nuke” threat to South Korea, building on the messaging from its February 8 military parade and its October 2022 commentary on last year’s missile activities.

Potential Silo-launched KN-23

The photos associated with the March 19 launch show the missile beginning to rise above a hilltop and its exhaust flame rising on either side of the missile in a V-shape rather than in a single plume extending below the missile. This exhaust pattern is typical of a launch from an underground silo rather than from the road-mobile transporter-erector-launcher (TEL) used in most KN-23 land launches. However, North Korea has not previously launched any of its ballistic missiles from a silo. (It also is not known to have launched KN-23s from a stationary launch stand equipped with a diverter/flame-splitter, which could also account for the V-shaped plume.)

Commercial satellite imagery of the launch area described in the North Korean statement and seen in the photos revealed a circular excavation resembling a silo opening on a hilltop, surrounded by a rectangular clearing served by a recently built road. Initial assessments regarded this as “a rudimentary engineering prototype missile silo” rather than the more substantial, hardened type of silo used by the US, USSR/Russia and China.[1]

Subsequent analysis in 38 North, however, questions whether the circular excavation is a silo and judges the launch more likely occurred from a TEL in the rectangular clearing surrounding the silo. This analysis makes a compelling case that the “silo” may only be one meter deep (the KN-23 is some 7.5 meters long). The alternative possibility considered in the analysis—that the apparent “bottom” of the silo actually is the “top” of a missile canister within a deeper silo—seems unlikely given the short amount of time available to have excavated a deep enough shaft in the rock base of the hilltop (about 18 days between the observed beginning of the circular excavation and the launch). Moreover, the KN-23 apparently has not used a launch canister before, and there has been no previous open-source evidence, such as canister handling equipment or ejection testing, linking this launch mode to the KN-23. The pattern of debris at the site in post-launch imagery is consistent with either a launch either from the silo or a nearby TEL.

Interestingly, the North Koreans did not announce the launch mode (atypical if a new silo mode had been used), did not show it in any of the released photos, did not release video footage of the launch, and covered the “silo” after launch with a square cover previously located to the side of the excavation. It is unclear whether the photos showing a V-shaped launch plume that fed the silo assessment were the result of a silo or launch-stand launch, if they resulted from some sort of unknown obstruction in the exhaust of a standard TEL launch, or if the photos had been altered by the North Koreans.

The initial assessment of a silo having been used led to the consideration of a wide range of potential implications.[2] Even if this KN-23 launch did not come from a silo, North Korea could decide to use silo basing at any point in the future. Therefore, these potential implications remain worth keeping in mind.

• Launching the KN-23 from a silo would be in character with the North’s use of this missile in a variety of basing modes, including TEL, railcar, submarine and a probable submersible platform lowered onto a lakebed. Pyongyang has gone out of its way to signal that it has a diverse missile force with multiple basing modes that can survive any attempts at “decapitation” or “preemption.” It likewise probably relishes the implication that many more missiles might be hidden around than its adversaries are aware of. Indeed, that might account for it releasing a photo suggesting a silo launch while not yet providing any further substantiation.
• As in the case of most of these other basing modes, however, silo basing makes less sense for SRBMs like the KN-23, which are relatively easy to move via TELs based on widely available truck chassis, than for larger, heavier missiles that are harder to move on wheeled vehicles using more exotic truck chassis. Silos are highly vulnerable to detection and attack regardless of the missile type and, thus, are unlikely to be seen by North Korea as a preferable basing mode.
• Silos do have the advantage of being cost-effective to operate and maintain once built, and even construction could be relatively inexpensive if the North decided to deploy missiles in “rudimentary” silos without the hardening and other infrastructure used by other countries. (It is not clear how long noncanisterized missiles could remain viable in such silos or what the maintenance costs of such deployments would be.) Using silos also makes credible the addition of decoy silos to confuse opponents about force size and location and cause them to waste weapons on worthless targets.
• The potential use of silos also highlights the possibility of yet further basing modes in the future for the KN-23 or other missiles, as was subsequently demonstrated when the North unveiled a “nuclear underwater attack drone” on March 24 (which will be the subject of a future article in 38 North). Prior to that unveiling, analysts were placing their bets on the next basing mode being an air-launched KN-23 akin to Russia’s use of the similar Iskander SRBM with a MiG-31 fighter in the Kinzhal system.[3]

The most disturbing possible implication identified by analysts keys off of the fact that missiles deployed in silos are easier to keep ready for launch at all times and provide no visual clues of an impending launch.[4] If North Korea deployed large numbers of SRBMs like the KN-23 in silos, these analysts posit, it would be easier for Pyongyang to launch a surprise or “preemptive” attack on South Korea—and the allies would be under pressure to preempt (or pre-preempt) these missiles before they could be silo-launched, in turn further increasing the pressure on North Korea to “use them or lose them.”

However, this scenario is highly unrealistic, as it depends on North Korea deciding to deploy a large proportion of its SRBMs or other missiles in silos. But Pyongyang has already been deploying scores of road-mobile SRBM launchers and hundreds of associated missiles for many years and continues such deployments with both SRBMs and longer-range systems. Any silo deployments would almost certainly augment rather than supplant this large extant mobile missile force—particularly because the North clearly has long recognized the vulnerability and other wartime operational downsides of fixed-based missiles compared to mobile ones. This would be especially true for nuclear-armed missiles, which North Korea would want to preserve from attack during a period of conventional conflict that is highly likely to precede any nuclear use. If TEL chassis are hard to come by, rail-mobile deployment provides a cost-effective alternative to silos with greater survivability.

We do not know if the March 19 KN-23 launch came from a silo, but that appears unlikely. Although adding silo-deployed missiles to the North’s longstanding road-mobile missile force may have some economic advantages, the vulnerability and operational downsides of silo-based missiles are highly likely to limit their proportion of Pyongyang’s overall missile deployments. This, in turn, is likely to limit the downsides to the alliance of any silo-based North Korean missiles.

1. [1]

   See CSIS Korea Chair. Twitter Post, March 20, 2023, 4:36 p.m., https://twitter.com/CSISKoreaChair/status/1637916125408239617; and Open Nuclear Network. Twitter Post, March 21, 2023, 8:02 a.m., https://twitter.com/OpenNuclear/status/1638149148972298240.

2. [2]

   For example, see Decker Eveleth. Twitter Post, March 21, 2023, 2:19 p.m., https://twitter.com/dex_eve/status/1638243890468884480; Decker Eveleth. Twitter Post, March 19, 2023, 8:24 p.m., https://twitter.com/dex_eve/status/1637611067051331585; Scott LaFoy. Twitter Post, March 19, 2023, 8:44 p.m., https://twitter.com/wslafoy/status/1637615993173180418; Open Nuclear Network. Twitter Post, March 21, 2023, 8:02 a.m., https://twitter.com/OpenNuclear/status/1638149148972298240; and Michael Duitsmann. Twitter Post, March 19, 2023, 9:47 p.m., https://twitter.com/DuitsmanMS/status/1637632021139959808.

3. [3]

   For example, see Nathan J Hunt. Twitter Post, March 20, 2023, 12:28 a.m., https://twitter.com/ISNJH/status/1637672344373145601; and Missile Defense Project, “Kh-47M2 Kinzhal,” Missile Threat, Center for Strategic and International Studies, last modified March 19, 2022, https://missilethreat.csis.org/missile/kinzhal.

4. [4]

   See Ankit Panda, “North Korea’s new silo-based missile raises risk of prompt preemptive strikes,” NK Pro, March 21, 2023, https://www.nknews.org/pro/north-koreas-new-silo-based-missile-raises-risk-of-prompt-preemptive-strikes; and Decker Eveleth. Twitter Post, March 19, 2023, 8:24 p.m., https://twitter.com/dex_eve/status/1637611067051331585.