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North Korea: The next Armageddon?

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by Mark Toth and Jonathan Sweet, opinion contributors - 04/16/26 7:00 AM ET

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by Mark Toth and Jonathan Sweet, opinion contributors - 04/16/26 7:00 AM ET

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AP Photo/Ahn Young-joon, File

Iran isn’t the only Axis of Evil ally in pursuit of a nuclear arsenal to ensure regime survival. North Korea –– long since far ahead of Iran –– is already there, and the threat is getting worse.

Speaking in Seoul, South Korea, Rafael Grossi, the Director General of the International Atomic Energy Agency, warned that the North Korean threat is rapidly increasing. The rogue state, he said, is making “very serious” advances in its capacity to add to its steadily growing nuclear arsenal.

The Federation of American Scientists –– a nuclear watchdog group founded in 1945 by Manhattan Project scientists and engineers –– estimates that North Korea, as of early 2026, has assembled an arsenal of 60 nuclear warheads.

Grossi is basing his risk assessment on satellite-confirmed increased activity at the Yongbyon Nuclear Science and Weapons Research Center –– the country’s primary nuclear facility located in Nyŏngbyŏn, 100 miles north of Pyongyang.

Its 5 MW nuclear reactor, he said, is “capable of producing six kilograms of plutonium a year that can be used by Pyongyang to continue expanding the size of its nuclear weapons stockpile.”

David Albright, the founder of the Institute for Science and International Security, assesses that North Korea needs about 4 kilograms of plutonium — a baseball-sized chunk — for a plutonium-only nuclear warhead.

Yet, as Grossi observed, it is the other activity at Yongbyon that is more alarming. This suggests that North Korea is expanding beyond plutonium-only and simple highly enriched uranium fission warheads toward more efficient composite-core designs, which mix plutonium and uranium in a single stage.

Additionally, Pyongyang is likely pursuing a smaller number of true two-stage thermonuclear weapons capable of far more powerful yields.

Stockpile estimates are tricky, given that this is a fast-moving target. Also bear in mind that the size and composition of North Korea’s nuclear arsenal could vary greatly depending on how it balances its stockpiles of plutonium and highly enriched uranium.

For example, if Pyongyang built only simple fission weapons –– plutonium-only or uranium-only –– Albright estimates it could possess between 59 and 104 nuclear warheads. But given that plutonium is the limiting factor –– as of now, North Korea is estimated to have produced 63 kilograms of it –– North Korea is likely increasingly turning to composite-core designs which are more efficient.

Composite-core designs create added benefits as well. They can deliver higher explosive yields for the same size and mass as plutonium-only warheads. That is key as Pyongyang continues to refine its warhead delivery systems –– especially its intercontinental ballistic missiles that are being perfected to strike the U.S. mainland.

In reality, extrapolating from Albright’s assessment that is based on estimated available plutonium and highly enriched uranium, North Korea’s nuclear arsenal is likely a mix of four types: 15 or fewer plutonium-only devices, about 15 uranium-only simple fission warheads, around 20 composite-cores, and a smaller number of two-stage thermonuclear bombs.

Significantly, it is increasingly clear that North Korea is expanding its uranium enrichment capacity.

In addition to its Kangson enrichment site –– an undeclared facility located near Pyongyang –– Grossi announced in March that construction of a second enrichment site located inside of Yongbyon had been finished. He noted that “internal fitting is likely underway.”

Grossi’s warning is not surprising. Kim Jong Un, the supreme leader of North Korea, has a long history of doubling down on his nation’s nuclear weapons program when the world — and especially the U.S. — is distracted.

We witnessed this during 2022, when Russian President Vladimir Putin launched his war against Ukraine. Pyongyang, by October of that year, had launched a record 23 ballistic missile tests, many of which crossed over the Sea of Japan. At one point, North Korea fired off five missiles in nine days.

A similar thing happened this last January, shortly after President Trump’s apprehension of former Venezuelan President Nicolas Maduro. Pyongyang, Military Magazine reported, “launched a nuclear-capable ballistic missile with a hypersonic glide vehicle … which traveled 1,000 kilometers before hitting