North Korea’s “tactical-guided” ballistic missile test is no joke for Biden and South Korea

North Korea’s March 25 test of two short-range ballistic missiles should be taken seriously. These missiles threaten South Korea and Americans living there. The test unambiguously violates UN Security Council resolutions, and any miscalculation involving these missiles could escalate into nuclear war. War is not imminent or highly probable, but the risks are high. As such, the United States and the international community should respond firmly.

The tests indicate Pyongyang is serious about developing tactical nuclear weapons, which can be achieved by mounting nuclear warheads onto short-range ballistic missiles. After all, Kim Jong Un declared in January that he is pursuing “ultra-modern tactical nuclear weapons including new-type tactical rockets.” At the time, the broader international discourse overlooked this notable threat to South Korea and the United States. Pyongyang now appears to be putting Kim’s declared plans into action—and doing so in earnest.

President Biden reacted by warning that “there will be responses if they choose to escalate. We will respond accordingly.” He also stressed that his administration is prepared for “some form of diplomacy, but it has to be conditioned upon the end result of denuclearization.” Pyongyang then criticized Biden for making statements that were “detrimental to the dignity and sovereignty” of North Korea and warned of consequences if Washington continued to make “unreasonable remarks” aimed at “slandering” North Korea “as the gravest threat to [America’s] security.”

While these short-range missiles may not be immediate threats, they could be tipped with nuclear, biological, or chemical warheads. In such a case, these missiles could hold South Korea hostage or target South Korea and Americans living there. They could even start or be used early in a conflict with South Korea and the United States. All of these scenarios affect the United States and the world.

Smaller, but dangerous missiles. In May 2019, the Bulletin of the Atomic Scientists published an article in which Melissa Hanham and I explained why these particular short-range missiles should not be overlooked in favor of focusing only on intercontinental ballistic missiles. In April 2019, Pyongyang claimed to have tested a “tactical guided weapon,” which was the start of a testing binge of short-range, solid-fuel ballistic missiles that summer (and other weapons systems) they called “rockets.” As all ballistic missiles violate UN Security Council resolutions, North Korea might have believed this word game would help it avoid international condemnation. Also, then US president Donald Trump ignored and condoned the tests. In stark contrast, Pyongyang has called last week’s tests “missiles” for “tactically guided” short-range ballistic weapons. Perhaps North Korea no longer feels the need to play nice since the pseudo summitry and bromance ended with Trump’s election defeat.

So far, the March 25 test appears to be an improved variant of North Korea’s KN-23 (Russian) Iskander-style short-range ballistic missile launched in 2019. It might also have been one of the missiles shown off during North Korea’s military parade in January. Pyongyang’s state-run news agency claimed they were “newly developed new-type tactical guided missiles” that “improved the weight of its warhead to 2.5 tons” and traveled 600 kilometers (km) towards Korea’s East Sea (also called the Sea of Japan). Japan’s cabinet secretariat said they flew about 420 km and 430 km respectively, which suggests one of the new short-range, solid-propellant missiles tested in 2019, according to Jefferey Lewis, a missile expert at the Middlebury Institute. US and South Korean militaries calculated a distance of 450 km, which some South Korean experts claim is an underestimate of 150 km due to the allies’ inability to detect an intentional design feature of the missile that accounted for the discrepancy with Pyongyang’s claimed missile trajectory calculation.

That feature allows the KN-23 missiles and last week’s variant to perform “pull up maneuvers” in flight, which concerned Vipin Narang, a professor specializing in nuclear weapons at the Massachusetts Institute of Technology. The purpose of pull-up maneuvers is to evade and penetrate missile defenses. He also pointed out that the biggest news about these missiles was Pyongyang’s claimed massive payload upgrade of 2.5 tons, which has nuclear implications and provides flexibility for Pyongyang to use existing warheads without the need to reliably design a compact 500 kg warhead.

The short-range ballistic missiles tested in 2019 and those on March 25 (albeit with some variation) are dangerous. First, these missiles fly at low trajectories and have jet vanes, which means they are designed to challenge ballistic missile defenses and can be maneuvered in flight. Airborne mobility makes it harder to predict where the missiles will land in South Korea, harder to intercept before they land, and more difficult to detect their launch locations. The latter means that North Korea might be able to launch more missiles before the United States and South Korea could detect their launch location and neutralize them. Their maneuverability also makes it harder for the United States and South Korea to intercept them in flight, even though their military authorities each claim they possess intercept capabilities.

Second, these missiles are difficult to intercept during war because they are road-mobile, which means that Pyongyang can easily move and hide them. Washington and Seoul would need to expend many resources to monitor their locations continuously. The mobility of these missiles could also confound existing US and South Korean intelligence capabilities that are otherwise said to be able to determine the type of warhead inside a missile by identifying its original storage location.

Third, Pyongyang appears interested in launching them from tracked vehicles, which suggests it might try to deploy a large number of missiles and launchers.

Fourth, their engines use solid-fuel propellants. This means North Korea can store and move these missiles pre-fueled, which keeps them ready for longer periods and makes them harder to detect and quicker to launch.

Finally, the warheads of these missiles can be nuclear or conventional. Such dual capability presents a challenge to how the United States and South Korea determine their response to a missile launch in seconds. For example, the allies might be tempted to strike down one of these short-range ballistic missiles before launch, without the ability to decipher whether it is carrying a nuclear or conventional warhead. This could prompt Pyongyang to fire the missiles to prevent losing them. These types of scenarios, according to game theory, increase the likelihood that a conflict could escalate into nuclear war.

A proportional response. Pyongyang’s March 25 launch of these short-range ballistic missiles warrant penalties because of the nature of the missiles and their violations of UN resolutions. But finding a proportional response sweet spot will be tricky. A new American administration is wrapping up its policy review and has repeatedly expressed its intent to engage diplomatically with Pyongyang. Diplomacy should certainly take the lead. South Korea’s progressive government would also oppose any firm action, and securing cooperation from China and Russia would be difficult. Still, the absence of or a weak response will embolden North Korea to sharpen its gray-zone tactics and gain influence.

The Biden administration and the international community have a range of response options while pursuing a strategy of engagement. For example, the UN Security Council should convene an emergency session despite geopolitical challenges it will face among member states in agreeing on a unanimous response. The aim of such a meeting should be to identify better enforcements of existing sanctions while also preparing a plan for quickly responding to future UN violations with new sanctions. Council members indeed met soon after the test, but failed to act—unable to even issue a statement of condemnation, which is usually the weakest action taken by the UN. Silence by the UN Security Council and the failure to impose any costs give Pyongyang the greenlight to conduct more missile tests to perfect its nuclear weapons technology.

Sanctions are not the key to solving the nuclear problem and there are questions about their effectiveness, but they can serve as penalties, ways to dry up funds for nuclear weapons, and chips to be bargained away in negotiations. The sanctions regime has eroded since 2018 as China and Russia have not fulfilled their obligations and have been found complicit in Pyongyang’s sanctions-evasion activities. It would be difficult or impossible to designate new UN sanctions without an extremely convincing rationale for Beijing and Moscow. The coronavirus pandemic has also served as the ultimate sanction, as it has forced North Korea to close its border and shut down nearly all trade with China, its biggest benefactor.

Still, sanctions could be imposed during a pandemic on North Korea’s cybercrimes and associated illicit financial activities as well as on countries, entities, and individuals assisting, trading, or working with Pyongyang. The regime has been found to have generated millions of dollars in revenue to fund its nuclear weapons program by stealing cryptocurrency, laundering digital money, and engaging in cyber hacks. The United States and like-minded countries could also persuade financial institutions to use artificial intelligence to combat hidden codes of money laundering, as recommended by sanctions expert Andrea Mihailescu.

Second, the latest missile tests have heightened security concerns in South Korea and Japan. US military presence on the Korean Peninsula has so far succeeded in deterring a North Korean invasion of or attacks against South Korea since the 1950-1953 Korean War. Still, the latest missiles are another reminder that the allies could do more to strengthen their readiness and deterrence posture, especially in light of the significant downsizing of US-South Korean military exercises to computer simulations. For example, they could consider resuming joint military drills at the scale, scope, and schedule prior to the Trump-Kim summits, but exclude US strategic assets (like bomber flyovers) until a bigger provocation or escalation. While field exercises and live fire drills may not directly add value to defending against and responding to Iskander-style ballistic missiles, they would help strengthen overall readiness. However, the current South Korean government would staunchly oppose this approach because it does not want to aggravate Pyongyang while it aspires to facilitate US-North Korean summitry and bring peace to the Korean Peninsula before its president leaves office next May.

Defense and readiness against these short-range missiles instead would come directly from strengthening the intercept and intelligence capabilities by the United States and South Korea. The allies reportedly made progress upgrading the interoperability of South Korea’s Terminal High Altitude Area Defense and America’s Patriot missile defense systems last year. But enhancing interoperability and strengthening ballistic missile defense continues to be a long-standing challenge and a slow endeavor for the allies, especially as South Korea seeks more national security autonomy and fears backlash from China.

Formulating a smart response to each North Korean provocation and nuclear weapons advancement is certainly important, but Washington must get out ahead of Pyongyang’s game plan by developing an overarching strategy. This surely is no easy task after decades of failed efforts to reverse Pyongyang’s nuclear pursuits. But the global consequences and stakes are too high to allow the regime’s nuclear weapons program to advance even further.

On Friday, the Biden administration is slated to debrief South Korean and Japanese allies on the key outcomes of its North Korea policy review. That policy will determine whether Washington and Pyongyang can embark on pathways toward denuclearization and peace, or whether North Korea’s shorter-range missiles will become destabilizing nuclear systems.