A North Korean Missile Explodes in the Sky—and a Mystery Emerges

SEOUL—North Korea said it had successfully tested technology for raining down multiple nuclear warheads at once—a top weapons goal for Kim Jong Un and an increased threat to the U.S. and its allies.

But, in an unusually pointed rebuke, South Korea denounced the self-declared achievement as a bluff.

The contradictory assessments illustrate high stakes for both Koreas: Seoul is trying to keep close tabs on its neighbor’s missile program as Pyongyang develops an increasingly capable nuclear threat. North Korea covets multi-warhead weapons because they are harder to defend against.

Relations between the neighboring countries have worsened in recent years, growing more militaristic and confrontational. Kim abandoned hopes of peaceful reunification in January and signed a new defense pact with visiting Russian President Vladimir Putin just last week. South Korea, under conservative Yoon Suk Yeol, has tightened its military partnership with the U.S. and Japan, including new three-way drills that began Thursday.

The truth from Wednesday’s fiery test isn’t so readily apparent, weapons experts said. Both Koreas conceded a missile roared into the sky and then left a trail of smoke behind before crashing into the water.

In North Korea’s state-media account, three separate warheads fired from an intermediate-range missile hit their unspecified targets. State media released photos of smoke trails it claims show warhead separation. But the images make it difficult to confirm the missile’s flight characteristics, and North Korea has fabricated details of its weapons achievements before, the experts say.

Among the top weapons priorities that Kim detailed in a policy speech in 2021, one was possessing the ability to launch several nuclear warheads from a single missile—or, in military parlance, a “multiple independently targetable re-entry vehicle,” or MIRV. Having that would raise North Korea’s threat to the U.S., since multiple warheads can be aimed at different targets at once. Pyongyang wants to add MIRV capabilities to its long-range missiles that already have a demonstrated range to strike the U.S. mainland.

South Korea’s Joint Chiefs of Staff dismissed the Kim regime’s assessment as “deceptive and exaggerated.” Seoul labeled the Monday launch as a test of hypersonic technology. Hypersonic missiles fly at high speeds and closer to the Earth than ballistic missiles, which makes them difficult to detect on radar. While the separation of warheads in a MIRV test would occur on the descent, the North Korean missile launched on Wednesday exploded in the flight’s initial stage, a South Korean Joint Chiefs of Staff spokesman said.

A multi-warhead missile uses complex technology. North Korea has yet to demonstrate it can mount even a single warhead onto a missile that safely re-enters the atmosphere after withstanding enormous pressure and heat. The Wednesday launch was intentionally carried out within a smaller radius for safety reasons, Pyongyang said.

Some of the experts think South Korea may have erred in their assessment, identifying the intended warhead separation as an accidental explosion. The North Korean imagery of the launch isn’t sufficient in quality to make a firm determination. Without elaboration, Seoul’s military defended its conclusion by saying it had relied on classified information and data that couldn’t be shared publicly.

The MIRV system that North Korea is working on is based on old Soviet technology, but it is unlikely that Russia would transfer such key nuclear technologies despite recently vowing closer military cooperation with Pyongyang, including last week, said Yang Uk, a military expert at the Asan Institute for Policy Studies in Seoul.

“We haven’t seen evidence that North Korea’s warheads successfully hit the targets or whether the launch was successful, but the continued investment in this technology means North Korea is advancing the capability to launch a nuclear strike on the U.S.,” Yang said.

With its botched spy-satellite launches in recent years, including one last month, North Korea has come clean on its failures within hours. But Pyongyang has a record of stretching the truth about other weapons advances. In 2022, Pyongyang claimed to have fired the Hwasong-17, one of its newer intercontinental ballistic missiles. It turned out to be an older-generation Hwasong-15, and Seoul’s military concluded that footage released by state media was heavily edited.

“Exaggeration can be a political tool to showcase a deterrent against U.S. and South Korea’s military capabilities,” said Park Won-gon, a professor of North Korean studies at Ewha Womans University in Seoul.

Write to Dasl Yoon at [email protected]