An Assessment of North Korea’s Growing Nuclear Capabilities

Remarks by Daryl G. Kimball
Catholic Korean Peace Forum
Catholic University of America
Oct. 5, 2022

For more than three decades, North Korea’s nuclear weapons ambitions have posed a major foreign policy challenge for U.S. presidents and for the international community. On-and-off U.S.-led diplomatic efforts to address North Korea’s safeguards and nuclear Nonproliferation Treaty violations, and rein in its nuclear weapons capabilities have, over the years, yielded some important but limited results.

Although these diplomatic efforts and sanctions have slowed North Korea’s nuclear program, Pyongyang has built up a small but dangerous nuclear weapons stockpile and an increasingly sophisticated ballistic missile arsenal. Today, North Korean nuclear-armed ballistic missiles could strike targets in Northeast Asia and some North Korean ICBMs may have the range necessary to reach the United States but with an uncertain degree of targe accuracy.

North Korea was a top nuclear and foreign policy challenge for Presidents Bush, Clinton, Bush, Obama, Trump, and the Biden administration, but it has not always been the top foreign policy priority for U.S. presidents, and U.S. and South Korean and Japanese and Chinese policy vis-a-vis North Korea have rarely been in alignment over the years.

U.S. policy has been inconsistent in recent years. President Trump’s initial approach to North Korea was like that of his predecessors: ratchet up pressure on North Korea through sanctions and international isolation, while expressing an openness to dialogue if North Korea demonstrates a commitment to denuclearization.

Then, after a series of very dangerous, escalatory implied nuclear threats and “fire and fury” from Trump in response to North Korean missile tests in late 2017, including tests of the Hwasong-14 and Hwasong-15 (its first intercontinental-range ballistic missiles) Trump reversed course and accepted a government of South Korea-brokered invitation to meet with North Korea’s leader, Chairman Kim Jong-un, in 2018.

Trump and Kim agreed at their June 2018 summit in Singapore to transform U.S.-North Korean relations to try to build peace and security in the region and denuclearize the Korean peninsula. North Korea announced a voluntary nuclear testing and long-range ballistic missile flight testing pause, and the United States scaled back its military exercises with the Republic of Korea.

The first summit yielded a brief but important statement of goals and principles for peace and denuclearization on the peninsula, but the meeting failed to lead to a sustained process of negotiations. When Trump and Kim met for a second summit in February 2019 in Hanoi, they could not agree on concrete steps toward the broad goals agreed to in Singapore. This was due in large part to the mixed messages, inflexibility, and maximalist positions pursued by the Trump administration as well as Chairman Kim.

North Korea's nuclear testing pause prevented it from making certain qualitative advances to its warhead designs, but Pyongyang has continued to produce fissile material for its nuclear weapons program and has resumed testing short-, medium-, and very recently longer-range ballistic missiles. It has also likely continued to produce additional numbers of already-tested types of short-, medium-, and longer-range ballistic missiles.

Fissile Material As a result, in the absence of sustained peace and disarmament diplomacy, North Korea’s nuclear and missile capabilities continue to expand. Today, it is estimated that North Korea has producedenough fissile material for 40-50 nuclear warheads, although the exact number of the stockpile remains unknown.

While there is uncertainty about North Korea’s fissile material stockpile and production capability, it is estimated they have 20-40 kilograms of plutonium and 250-500 kilograms of highly enriched uranium. The estimated annual production of fissile material could be enough for 6-7 additional weapons.

North Korea has a centrifuge facility in Yongbyon Nuclear Scientific Research Center, which is likely used to produce highly enriched uranium weapons, and there is likely at least one other centrifuge facility in the country.

Production of fissile material at Yongbyon has been halted for political and technical reasons at various points, including in 2018 following summits with the U.S. and South Korea. However, in August 2021, the IAEA raised concerns that Pyongyang had restarted its plutonium production reactor at Yongbyon.

Intermediate- and Longer-Range Ballistic Missiles In late 2019, with denuclearization and peace talks stalled, Pyongyang formally announced it would no longer abide by its voluntary long-range missile and nuclear test moratorium. Long-range, or intercontinental ballistic missiles (ICBMs), are those with a range of more than 5,500 kilometers and are powerful enough to deliver a nuclear warhead. 

In 2019, North Korea conducted tests of three new shorter-range missile systems, code-named KN-23, KN-24, and KN-25. Unlike its older missiles that use liquid fuel, all three of the new missiles use solid fuel. The new solid-fuel weapons, mounted on mobile launchers, are easier to transport and hide and take less time to prepare. And at least two of them, KN-23 and KN-24, could perform low-altitude maneuvers, making them harder to intercept.

October 2020, the regime paraded a new ICBM significantly larger and more powerful than prior systems. More recently it has begun to test components and capabilities related to ICBMs. In March 2022, it flight-tested a what was believed by South Korea to be an older Hwasong-15 long-range ballistic missile. This past week, North Korea flight-tested another its Hwasong-12 intermediate-range ballistic missiles from Mupyong-ri, near North Korea’s central border with China. It passed high over Japan and crashed into the Pacific Ocean 22 minutes later, about 4,600 kilometers from the launch site.

In early 2022, independent researchers at CSIS uncovered what is likely a new North Korean base for launching intercontinental ballistic missiles (ICBMs) at a location some 25 kilometers from the Chinese border in Chagang Province. The Hoejung-ni missile operating base will likely house a regiment-sized unit equipped with North Korean intercontinental ballistic missiles.

It should also be noted that South Korea has developed its own ballistic missile capabilities in recent years. For example, in 2020, South Korea conducted two tests of the new solid-fueled Hyunmoo-4, which boasts an 800-kilometer range and an estimated payload capacity of 2 metric tons.

In early 2021, bilateral guidelines that have long restricted the development of South Korea’s ballistic missile program were terminated, according to an agreement announced by President Moon Jae-in at his summit with U.S. President Joe Biden at the White House May 21. In September 2021, it launched a ballistic missile from a submarine making it the first country without nuclear weapons to develop that capability.

A de facto ballistic missile arms race is underway on the peninsula.

North Korean Nuclear Weapon Test Explosions North Korea has also conducted six nuclear weapons tests between 2006 and 2017, the last of which produced an explosive yield of more than 100 kilotons of TNT equivalent. This strongly suggests that North Korea has successfully tested a compact but high-yield nuclear device that can be launched on intermediate- or intercontinental-range ballistic missiles. Additional tests would help North Korea perfect such a design.

Following the start of U.S.-DPRK summit diplomacy in 2018, North Korea made a show of disabling test tunnels at its Punggye-ri nuclear test facility.

But now, the IAEA and U.S. intelligence sources indicate that North Korea has resumed activity at its test site and may be preparing to conduct its seventh underground nuclear test explosion, which could help North Korea proof test a more compact, more efficient but still very powerful nuclear warhead that is better suited for delivery on a long-range ballistic missile.

North Korea's Updated Nuclear Policy Law It is also important to note that in September 2022, Kim Jong Un announced a new law outlining North Korea's nuclear posture, which says that: “the nuclear forces of the DPRK are a powerful means for defending the sovereignty, territorial integrity and fundamental interests of the state.”

The policy asserts that North Korea is a “nuclear weapon state" despite the fact that the international community considers North Korea to be, from a legal perspective, a non-nuclear weapon state party to the nuclear Nonproliferation Treaty (NPT) that is in flagrant violation of its IAEA safeguards and nuclear Nonproliferation Treaty obligations, despite North Korea's claim that it withdrew from the NPT in 2003.

North Korea's new nuclear law also asserts that North Korea's leaders have a right to “use a pre-emptive nuclear strike to protect itself,” which reinforces long-standing assessments that North Korea would use nuclear weapons early in a conflict against the RoK and other targets if it believes it is under attack from U.S. or RoK forces. The updated nuclear policy strongly suggests North Korea is far less willing than it may ever have been in the past to consider negotiating "denuclearization" for "peace and normalization" of relations with the United States and its allies.

Implications and Next Steps

The bottom line in my view is that North Korean nuclear and missile capabilities remain dangerous to the region and that danger is gradually growing. And South Korea risks accelerating the missile arms race by pursuing its own capabilities.

Without a lasting freeze of North Korea's missile and nuclear programs and restraint on the part of South Korea regarding its own ballistic missile programs, Pyongyang's capabilities will increase and will soon pose a threat to the mainland United States.

Obviously, diplomacy requires interest from both sides. But to kick-start diplomacy, the Biden administration can and should do more than continue to express a willingness to engage in talks anywhere, any time.

The Biden team has a lot of crises to manage right now, for sure, but it can and should signal, privately and publicly that is prepared to pursue a principled but flexible, step-by-step approach that rewards concrete steps toward denuclearization with meaningful and calibrated sanctions relief and mutual confidence-building moves that simultaneously reduce tensions and the risk of conflict. President Biden should also signal that he recognizes North Korea’s stated security concerns.

Rapid elimination of all North Korean missiles and nuclear facilities prior to Pyongyang receiving any sanctions relief, a process proposed by Trump in Hanoi, is unrealistic.

To manage, reduce, and eventually eliminate the growing risks posed by North Korea’s arsenal, the United States and its partners will first need to focus on dismantling the most dangerous elements and continue work to sustain the denuclearization and peace process over time.

As Pope Francis cautioned when he visited Hiroshima in 2019: “The use of atomic energy for purposes of war is immoral…. Future generations will rise to condemn our failure if we spoke of peace but did not act.” Thank you for your attention

*The author wishes to acknowledge research support from ACA's policy intern, Heather Foye.