A sign in a Korean restaurant in Hanoi welcomes President Trump and Kim Jong Un, who are scheduled to meet on Feb. 27-28 in the Vietnamese capital. (Linh Pham/Getty Images)

Siegfried S. Hecker was the director of the Los Alamos National Laboratory from 1986 to 1997 and is a senior fellow emeritus at the Center for International Security and Cooperation at Stanford University. Robert L. Carlin is a visiting scholar and Elliot Serbin is a research assistant at the center.

Ahead of the President Trump-Kim Jong Un summit next week, the prevailing view in the United States is that Kim expanded North Korea’s nuclear program in 2018 despite pledging to do the opposite. But our findings paint a different picture. We have found that North Korea actually halted key elements of its nuclear program, thereby decreasing the threat posed by what was a rapidly expanding program in 2017.

First of all, on the diplomatic front, Kim took decisive steps in 2018 to initiate improved relations with South Korea, the United States and China. The historic Kim-Trump Singapore summit, as well as three summits between Kim and South Korean President Moon Jae-in, dramatically lowered tensions and reduced the threat of war on the Korean Peninsula.

On the technical front, we cannot just use the simplistic term “denuclearization” as the standard by which we measure changes in North Korea’s nuclear program. We need to put into perspective the trade-offs among the three requisite components of North Korea’s nuclear arsenal: bomb fuel, weaponization and delivery systems.

On the one hand, North Korea has been expanding its bomb-fuel inventory, allowing it to potentially increase the size of its arsenal. This is what we would expect to see in the absence of any specific and binding limitations. But on the other hand, North Korea has slowed its weaponization (designing, building, testing) and delivery system development, limiting the sophistication and reach of its arsenal. Our findings indicate that the latter outweighs the former, resulting in an overall decreased threat.

We tracked the operations of key facilities in 2018 and prior years using open-source satellite imagery. Combining this analysis with our knowledge of these facilities based on visits to the Yongbyon nuclear complex over the years, we concluded that North Korea operated these facilities to produce sufficient plutonium and highly enriched uranium for approximately six bombs, in addition to the approximately 30 bombs’ worth that we estimate existed at the end of 2017. The addition of the equivalent of six or so bombs’ worth of fissile material is much less threatening than it would have been if the North had moved to perfect its intercontinental ballistic missiles (ICBMs) and hydrogen bomb capabilities through continued missile and nuclear testing last year.

These advances did not happen because in April, Kim took the extraordinary step of ending, not just suspending, nuclear and missile tests. He declared the nuclear test program to be unnecessary, claiming that North Korea had completed its state nuclear force. Indeed, North Korea did not test-launch missiles of any range in 2018 — a dramatic turnaround from the flurry of tests during the prior few years. In May, Kim also took steps to destroy the nuclear testing tunnels at North Korea’s Punggye-ri test site.

The reality is that permanently ending nuclear and missile testing seriously limits North Korea’s advances in weaponization and delivery systems. It greatly restricts the country’s ambitions for ICBMs, solid-fueled missiles and submarine-launched missiles, all of which are still very much in the developmental stage, not completed as Kim claimed.

Of course, more can and should be done in 2019. At the upcoming summit, the United States should lock in the end of North Korea’s nuclear and missile tests and press for an end to its production of bomb fuel — plutonium, highly enriched uranium and tritium. This would be mostly accomplished by dismantling the Yongbyon nuclear complex and putting U.S. and international inspectors on the ground there. In addition to its uranium chemical facilities and the known centrifuge facility at Yongbyon, North Korea has at least one suspected undisclosed uranium enrichment facility elsewhere, which will eventually need to be dismantled as well.

Still, contrary to the opinions of many Korea watchers, we conclude that Pyongyang has made much more progress on the denuclearization front than Washington has made toward normalizing U.S.-North Korea relations, which it pledged to work toward at the Singapore summit. Not surprisingly, North Korea has viewed the Trump administration’s policy of maximum pressure and sanctions as incompatible with normalization. At the summit, Kim will surely insist on, and the United States should be prepared to discuss, some form of sanctions relief.

We are encouraged by U.S. Special Representative for North Korea Stephen Biegun’s recent remarks that Washington needs “to advance our diplomacy alongside our plans for denuclearization in a manner that sends that message clearly to North Korea as well.” These remarks appear to signal a new flexibility in Washington to phase North Korea’s denuclearization in step with developing better relations and working toward a “peace regime” on the peninsula. We have previously argued that denuclearization must be phased step by step with normalization.

These developments are promising when coupled with Kim’s declaration on New Year’s Day to not only stop testing nuclear weapons but also to not produce or proliferate them. With these recent comments on both sides, and the slowing of the North’s weaponization in 2018, the stage may be set for progress at the summit on both normalization and steps toward halting, rolling back and eventually eliminating nuclear weapons in North Korea.

This was produced in collaboration with The WorldPost, a publication of the Berggruen Institute.

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