This article originally appeared on 38 North.

My reply to the frequently asked question if Kim Jong Un will ever give up North Korea’s nuclear weapons is, “I don’t know, and most likely he doesn’t know either. But it is time to find out.” However, insisting that Kim Jong Un give a full declaration of his nuclear program up front will not work. It will breed more suspicion instead of building the trust necessary for the North to denuclearize, a process that will extend beyond the 2020 US presidential election.

However, the time it will take to get to the endpoint should not obscure the progress that has already been made. Since this spring, Kim Jong Un has taken significant steps to reduce the nuclear threat North Korea poses. He has declared an end to nuclear testing and closed the nuclear test tunnels by setting off explosive charges inside the test tunnel complex. He also declared an end to testing intermediate- and long-range missiles including intercontinental ballistic missiles (ICBMs). I consider these as two of the most important steps toward reducing the threat North Korea poses and as significant steps on the path to denuclearization.

Whereas the North still poses a nuclear threat to Japan and South Korea as well as US military forces and citizens in the region, the threat to the United States has been markedly reduced. In my opinion, North Korea needs more nuclear and ICBM tests to be able to reach the United States with a nuclear-tipped missile. Freezing the sophistication of the program is a necessary precursor to rolling it back in a step-by-step process.

At the September 2018 inter-Korean summit in Pyongyang, Kim also told President Moon that he would commit to dismantling the Yongbyon nuclear complex if the US takes commensurate measures—unspecified, at least in public. The Yongbyon complex is the heart of North Korea’s nuclear program. Shutting it down and dismantling it would be a very big deal because it would stop plutonium and tritium production (for hydrogen bombs) and significantly disrupt highly enriched uranium production.

Yet, Kim’s actions have been widely dismissed as insignificant or insincere by both the left and the right of the American political spectrum. In many of these quarters, the sincerity of Kim’s denuclearization promise is judged by whether or not he is willing to provide a full and complete declaration and to agree on adequate verification measures. But Kim’s willingness to provide a full declaration at this early stage tells us little about his willingness to denuclearize. Moreover, I maintain that insisting on this approach is a dead end, certainly as long as Washington continues to apply “maximum pressure” instead of moving to implement the steps on normalizing relations that President Trump agreed to in the June Singapore statement.

A full declaration is a dead end because it is tantamount to surrender, and Kim has not surrendered, nor will he. A complete account of North Korea’s nuclear weapons, materials, and facilities would, in Kim’s view, likely be far too risky in that it would essentially provide a targeting list for US military planners and seal the inevitable end of the nuclear program and possibly his regime.

Furthermore, a declaration must be accompanied by a robust verification protocol. That, in turn, must allow inspections and a full accounting of all past activities such as production and procurement records as well as export activities. And, once all these activities are complete, an inspection protocol must provide assurances that activities that could support a weapons program are not being reconstituted. This would be a contentious and drawn-out affair.

It is inconceivable that the North would declare all of its nuclear weapons, their location, and allow inspections of the weapons or of their disassembly up front. But in addition to the weapons themselves, a nuclear weapon program consists of three interlocking elements: 1) the nuclear bomb fuel, which depending on the type of bomb includes plutonium, highly enriched uranium (HEU), and forms of heavy hydrogen—deuterium and tritium; 2) weaponization—that is, designing, building and testing weapons, and; 3) delivery systems, which in the case of North Korea appear to be missiles, although airplane or ship delivery cannot be ruled out. Each of these elements involves dozens of sites, hundreds of buildings, and several thousand people.

Let me give an example of what is involved just for verification of plutonium inventories and means of production. Plutonium is produced in reactors by the fission of uranium fuel. We estimate that most of the North’s plutonium has been produced in its 5 MWe (electric) gas-graphite reactor at the Yongbyon complex. A complete declaration must provide for the entire operations history (along with its design and operational characteristics) going back to its initial operation in 1986 to correctly estimate how much plutonium was produced.

In addition, North Korea has operated the Soviet-supplied IRT-2000 research reactor at the Yongbyon site since 1967. Although little plutonium has likely been produced there, this would have to be verified by providing the complete operating history along with performance characteristics since its initial operation. North Korea has also constructed an experimental light water reactor (ELWR) that is likely not yet operational. Its status would have to be checked to see if it was configured to favor weapon-grade plutonium production. Finally, North Korea began to build but never completed 50 MWe and 200 MWe gas-graphite reactors, whose construction operations were stopped by the Agreed Framework in 1994. Their status would have to be verified.

The 5 MWe reactor fuel consists of natural uranium metal alloy fuel elements. Tracking the entire history of fuel fabrication would be an important verification step for plutonium production. It starts with uranium ore mining, milling and conversion to uranium oxide. This is followed by a few additional steps to produce the uranium metal that is formed into fuel elements for the reactor to produce plutonium. Some of these same steps would also be used, but then complemented by turning the uranium into a compound that serves as the precursor gas (uranium hexafluoride) for centrifuge enrichment to produce low enriched uranium for light water reactors or highly enriched uranium for bombs.

A complete and accurate accounting of fuel produced would also likely show a discrepancy that indicates that more fuel was produced at Yongbyon than was consumed. The difference could be accounted for by the fuel that North Korea produced for the gas-graphite reactor it built in Syria, a project that was terminated by Israel’s air raid on the Al Kibar site in September 2007. North Korea is unlikely to acknowledge the illicit construction of the Syrian reactor as part of its own plutonium declaration.

Once produced in the reactor, plutonium has to be extracted from the used or spent fuel after a sufficient period of time that allows the spent fuel to cool thermally and radioactively. The extraction or separations process is accomplished in a reprocessing facility using mechanical and chemical methods. The North’s reprocessing facility became operational in the early 1990s. All of its operations records would have to be examined and verified. In addition, it is likely that some small amount of plutonium that may have been produced in the IRT-2000 reactor was separated in the hot cell facilities in that complex. Its records would have to be examined and verified.

After plutonium is separated, it must be purified, alloyed, cast and machined into final bomb components. Each of these steps generates residue and waste streams that must be monitored and assessed for their plutonium content. Based on my visits to Yongbyon and discussions with the North’s technical staff, I believe that the steps beginning with delivery of yellowcake to Yongbyon (from the uranium mining and milling sites), plus all steps for fuel fabrication, reactor production of plutonium, spent fuel cooling, reprocessing, plutonium purification and alloying into metal ingots are conducted at Yongbyon.

During my visits to Yongbyon, I was told that the plutonium ingots are then taken off site (of an undeclared location) in which the plutonium is cast into bomb components—which would then be followed by machining and assembling into pits, the plutonium cores of the weapons. In 2010, I was also told that all plutonium residues and wastes from reprocessing and plutonium metal preparation were still stored at Yongbyon (under questionable safety conditions). Very little had been done to prepare the spent fuel waste for final disposition. This is likely still the case and, hence, most of the reprocessing facility must remain operational after the rest of Yongbyon is shut down in order to prepare the hazardous waste for safe, long-term disposition. This will also complicate the plutonium inventory verification.

A complete declaration must also include how much plutonium was used during underground testing. In addition to the six known tests at Punggye-ri, North Korea also claims to have conducted “subcritical” experiments (stopping just short of a nuclear detonation), which I consider to be unlikely. If it did, however, North Korea would have to declare the amount of plutonium used and its current state, particularly since such experiments could leave plutonium in a usable form unlike the case for nuclear detonations. To verify the nuclear test history of plutonium, as well as for highly enriched uranium, it would be necessary to provide information or allow drill-back inspections into the test tunnels at Punggye-ri to ascertain the type and amount of nuclear material used in the test.

To complicate matters even further, if one or more of the North’s test devices failed to produce a nuclear explosion, then plutonium (or HEU) could still be resident in the tunnels. Both the United States and Russia experienced such test failures. This is also possibly the case for North Korea because there is still some uncertainty as to whether or not a nuclear test was conducted in May 2010 when a faint seismic signal was observed from the test area. For the most part, the jury is still out on that event, but the North would now have to allow inspections and verification.

It should be apparent that the declaration plus commensurate verification of the amount of plutonium North Korea possesses, which I believe is only between 20 and 40 kilograms, will be an enormous job. I cannot see it being accomplished in the current adversarial environment and certainly not within the timeframe that has been specified by the US government.

A similar sequence of declarations, inspections, and verification measures would have to be developed for the other bomb fuels, namely HEU and the hydrogen isotopes, deuterium and tritium. Verification of HEU inventories and means of production will be particularly contentious because very little is known about the centrifuge facility at the Yongbyon site. As far as we know, my Stanford colleagues and I are the only foreigners to have seen that facility, and then only in a hurried walk-through in 2010. In addition, there exists at least one other covert centrifuge site.

The situation is even more problematic for the second element of the North’s nuclear program, that of weaponization, which includes bomb design, production, and testing because we know nothing about these activities or where they are performed. Although we have some information regarding the nuclear test site at which six nuclear tests were conducted, we do not know if there are other tunnel complexes that have been prepared for testing.

The third element includes all of the North’s missiles and its production, storage and launch sites and complexes. These will also represent a major challenge for complete and correct declarations, inspections and verification.

Once all of the elements have been declared and the dismantling begins, then the focus will have to change to verifying the dismantlement and assessing the potential reversibility of these actions—a challenge that is not only difficult, but one that must be ongoing.

Verification was one of the sticking points during the 2007-2008 diplomatic initiative pursued late in the George W. Bush administration. In 2008, the North turned over copies of 18,000 pages of operating records of the reactor and reprocessing facilities in Yongbyon. The veracity of that disclosure has never been established because diplomatic efforts fell apart when the United States insisted on more declarations up front and North Korea accused Washington of having moved the goal posts. That declaration constituted only a small part of what I outlined above as being necessary for a full accounting of plutonium, not to mention the other components of North Korea’s nuclear program. That was 10 years ago, and much has happened since to make future declarations and verification much more problematic.

At this time, the level of trust between Pyongyang and Washington required for North Korea to agree to a full, verifiable declaration up front does not exist. Hence, my colleagues Robert Carlin and Elliot Serbin and I have suggested a different approach. Negotiations should begin with an agreed end state: North Korea without nuclear weapons or a nuclear weapon program. Civilian nuclear and space programs would remain open for negotiation and possible cooperation. But all facilities and activities that have direct nuclear weapons applicability must eventually be eliminated.

Rather than insisting on a full declaration up front, the two sides should first agree to have the North take significant steps that reduce the nuclear threat it poses in return for commensurate movements toward normalization—the details of which would have to be worked out during negotiations. A good next step for the North would be the destruction of the 5 MWe plutonium production reactor, which would be part of the package that Kim proposed to Moon at the Pyongyang Summit. If these actions are matched by US steps toward normalization as pledged in the Singapore statement, they will serve to build the trust required for the North to initiate a phased declaration process that initially covers operations in Yongbyon and eventually includes the entire nuclear program discussed above.

Unfortunately, the strategic opening created by the Singapore and North-South summits has not been followed by such tactical steps to get the negotiation process off the ground. The North and the South are ready to create a commonly acceptable path forward, but we have the worst of environments in Washington. The Trump team claims progress is being made but insists on maintaining maximum pressure. The North’s Foreign Ministry has pointed outthat the “improvement of relations and sanctions are incompatible.” Also, most US North Korea watchers are either wedded to old think that you can’t negotiate with Pyongyang or they are determined to prove President Trump’s claims on North Korea wrong.

With nuclear tensions on the Korean Peninsula dramatically reduced, it is time to find out if Kim’s drive to improve the economy will eventually lead to denuclearization. He may determine that his nuclear arsenal poses a significant hindrance to economic development that outweighs the putative benefits it confers. Washington and Seoul should work together to encourage rather than inhibit this potential shift.