One month and two tests into a world where North Korea possesses an intercontinental ballistic missile (ICBM), experts are still divided over the specifications and capabilities of the Hwasong-14 (HS-14) missile. The most striking example of the disagreement can be found in the vastly different range estimates generated, with at least six different estimates from reputable experts and institutions calculating between just over the 5,500 km ICBM ‘threshold’ to nearly 11,000 km. Despite the release of high-resolution photos and telemetry data, there is still debate about whether this is an ‘Alaska missile‘ or something that can reach New York City.
One source of the confusion is that the HS-14 came out of nowhere when a variant of its first stage, the HS-12, traveled five times higher than the International Space Station during its maiden flight just over two months ago. Only the HS-12 was displayed at the ‘JucheFest’ parade in April. The HS-14 borrows design elements from a Soviet submarine-launched ballistic missile (SLBM) half its size, but otherwise looks like no other missile and might be the only liquid-fueled, transportable ICBM ever deployed. The HS-14 is also smaller than other ICBM’s, with just two stages ostensibly carrying a single fission device inside a rudimentary re-entry vehicle (RV).
The separate assessments arrive by way of different answers to two questions: how big was the missile and what is inside the nose cone? At the upper end of the assessments, an as-yet unpublished Center for Nonproliferation Studies model being developed by Jeffrey Lewis and his team shows a large missile carrying a small payload a very long distance. By assuming a roughly 2-meter diameter, their calculations show it weighing 10% more than the new Russian RSM-56 Bulava SLBM with a small 500 kg re-entry vehicle. Anyone following Lewis’s podcast or Twitter account knows how impressive he finds the new North Korean hardware.
The lower-end estimates come from the work of James Kiessling and Ralph Savelsberg, working for the US Defense Department and the Netherlands Defense Academy respectively. While they agree with others that the HS-14’s height was between 18 and 19 meters, they believe that photos and videos released by the North Korean government have been manipulated to make the HS-14’s diameter appear larger than they think it is likely. The missile they have modeled, estimating only a 1.5-meter diameter (1/5th smaller than Tal Inbar’s 1.9-meter estimate) is smaller and carries a heavier payload and threatens only Alaska.
Unlike what some headlines have interpreted of their analysis, Kiessling is not arguing that North Korea is incapable of building ICBM. He believes that the HS-14 is a diversion from the real ICBM: a silo-based missile using the HS-12 as a second stage sitting atop an Unha space launch vehicle first stage. They calculate that such an arrangement could land an 800 kg payload anywhere in the United States with already proven technologies. The primary disadvantage of these missiles would be a loss of mobility and slow fueling times. The point of the diversion would be to have the US and its allies looking for mobile missiles hidden in buildings or caves instead of silos.
Questions about what is inside the HS-14’s nose cone are far more speculative. The second test had an apogee nearly 1000 km higher than the first test, but the new test doesn’t confirm any of the models because no one knows what was or wasn’t inside the nose cone. There is also no evidence that the North Koreans have mastered either nuclear miniaturization or designed an RV that can survive atmospheric re-entry that can reach speeds higher than Mach 20, but an absence of evidence is not evidence of absence. Videos taken in Japan of the most recent launched appeared to show the RV disintegrating before hitting the ocean have sparked questions about the survivability of their RV and any warhead inside. Others have pointed out that the videos are far from conclusive: it might not have been the RV, it might not have disintegrated if it was, and it might be under more stress from its lofted trajectory than it would be on its way to New York.
Kiessling fears that people will interpret Lewis’s work as concluding that there is still a window to strike North Korea before the HS-14 is debugged and deployed. Kiessling is arguing that the ‘real’ ICBM has yet to be tested and that it would be less survivable than the HS-14, but Lewis has been warning us for more than a year that any window of opportunity to remove North Korea’s nuclear missile threat has long passed. We should assume that after five tests they’ve miniaturized, that they will concurrently master RV technology like everyone else. Fretting over ICBM’s misses the point that shorter range weapons are likely already aimed at US forces in Japan and South Korea and might be able to defeat THAAD. North Korea’s missile threat is real, even if the technical details about the exact nature of the threat are still being debated.