“[My time at ACA] prepared me very well for the position that I took following that with the State Department, where I then implemented and helped to implement many of the policies that we tried to promote.”
– Peter Crail
Business Executive for National Security
June 2, 2022
Arms Control Today

On CTBT Anniversary, UN Members Call for Action

October 2021
By Daryl G. Kimball

Member states of the 1996 Comprehensive Test Ban Treaty (CTBT) marked the 25th anniversary of the opening for signature of the treaty with a series of events last month at the United Nations, culminating in a special Security Council meeting on Sept. 27 convened by Ireland, which holds one of the rotating seats on the 12-member council.

Maggie Wanyaga of Kenya, a representative of the Comprehensive Nuclear-Test-Ban-Treaty Organization Youth Group, addressed a UN Security Council meeting that discussed the CTBT on Sept. 27. The youth group is part of an effort to involve civil society in supporting the work of the CTBTO and the treaty. (UN TV)At the Security Council meeting, senior officials representing council members, including the six states that have conducted nuclear test explosions, spoke. The new head of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Organization (CTBTO), Robert Floyd; the head of the UN Office of Disarmament Affairs; and a civil society representative from Kenya also addressed the Council.

In a departure from the Trump administration, the U.S. envoy’s statement reaffirmed that the United States supports the CTBT and “is committed to achieving its entry into force.” China’s representative also reiterated Beijing’s support for the treaty. Both states have signed the CTBT but failed to ratify. Neither country’s representative indicated when they might seek to complete the ratification process.

India’s envoy told the council that his country “supports the realization of a nuclear weapons free world through a step for step process” and that India participated in the CTBT negotiations at the Conference on Disarmament (CD) but could not join the treaty “as it did not address our concerns.” He noted that India will continue to observe a nuclear testing moratorium and is committed to working on disarmament in the CD.

One hundred and eighty-five states have signed the CTBT and 170 have ratified it. Eight key states, including the United States and China and India, must still ratify the treaty for it to formally enter into force.

Since the tit-for-tat Indian and Pakistani nuclear tests of 1998, all states except North Korea have respected the strong de facto international norm created by the CTBT and upheld moratoriums on nuclear weapons testing. Since 2017, even North Korea has halted nuclear testing. The Security Council has condemned each of the handful of nuclear tests conducted since the CTBT’s opening for signature and imposed sanctions in each case.

The last time the Security Council addressed the CTBT issue was on Sept. 22, 2016, when it marked the treaty’s 20th anniversary with the adoption of Resolution 2310. In the resolution, the council stressed the “vital importance and urgency” of achieving the early entry into force of the treaty and urged all states to sign and ratify it. The council also recognized a joint statement from its permanent five members not to take any action that would “defeat the object or purpose of the treaty,” which is to halt “any nuclear weapon test explosion and any other nuclear test explosion.”

Due to opposition from France, however, this year’s special Security Council session did not result in a joint statement, according to multiple diplomatic sources.

Days earlier on Sept. 23 and 24, CTBT member states met for the Conference on Facilitating Entry Into Force of the CTBT, a meeting held every other year to “to promote cooperation aimed at promoting further signatures and ratifications.”

In a video address to the conference, Bonnie Jenkins, the U.S. undersecretary of state for arms control and international security affairs, said “an in-force CTBT is good for the security of the United States, and it is good for the security of all states.”

“I want to make clear,” Jenkins said, “the United States supports the CTBT and is committed to work to achieve its entry into force. This is no easy task. It is important to remember that no one country can make entry into force happen on its own. Within the United States, we recognize that securing the advice and consent of the U.S. Senate to ratification will require deliberate outreach and education to ensure that the benefits of an in-force CTBT are clearly understood by all.”

On Sept. 24, Russian President Vladimir Putin issued a statement on social media that said: “Countries that are yet to join the treaty need to show political will. The agreement’s entry into force would serve the interests of the whole global community of nations.”

At the insistence of states including the China and the United Kingdom, the CTBT text includes an unorthodox entry into force section, which is spelled out in Article XIV, and is designed to require that India and other nuclear weapons-capable states all join the treaty before it enters into force. Article XIV requires ratification by 44 named states, members of the Conference on Disarmament that also appear in the International Atomic Energy Agency’s (IAEA) list of states with nuclear power reactors. Two of the eight key holdout states, China and the United States, have signed the treaty and have refrained from testing, but they have not yet ratified and have not indicated when they will do so.

Article XIV also established the option for states-parties to the treaty to convene conferences to exhort holdout states to sign and ratify. Germany and Algeria co-chaired the Sept. 27 conference, which was the 12th such conference since the treaty was concluded, and then reported on their efforts to promote the treaty. Italy and South Africa will serve as co-chairs for the coming year.

UN member states also reaffirmed support for an end to nuclear testing at another high-level meeting at UN headquarters on Sept. 8. That conference marked the closure of the former Soviet Union’s former Semipalatinsk test site in eastern Kazakhstan. Thirty years ago, on August 29, 1991, the site was officially shut down after more than 450 nuclear detonations. The UN now recognizes the date as International Day Against Nuclear Tests.

Magzhan Ilyassov, Kazakhstan’s UN ambassador, speaking to UN News said, “For us, the 29th of August is not a day in the calendar. It is a reminder about how traumatic nuclear tests can be for humankind because in Kazakhstan alone, 1.5 million people still suffer, and will unfortunately suffer for future generations, from genetic diseases, cancer, leukemia, which were caused by exposure to nuclear tests.”

In a Sept. 30 statement, UN Secretary General António Guterres said, “I once again urge those states that have not yet ratified the treaty to do so without delay. Eight states whose ratifications are necessary for the treaty to enter into force have a special responsibility. At the same time, all states should maintain or implement moratoria on nuclear explosions. The International Day Against Nuclear Tests is an opportunity to reaffirm our commitment to outlaw all nuclear tests, by anyone, anywhere. There is no excuse to delay achieving this goal.”

U.S. President Joe Biden also recognized the day. “On behalf of the United States of America, I want to extend my best wishes to the people of Kazakhstan as you mark three decades since the closure of the Semipalatinsk nuclear test site on Aug. 29,” he wrote in a Sept. 1 letter to Kazakhstan’s President Kassym-Jomart Tokayev. “The United States remains committed to its close partnership with Kazakhstan, including continued cooperation with your government to secure and remediate the former test site,” Biden wrote.

For CTBT advocates, the Biden administration’s rhetorical support for the treaty is a welcome shift from the policy of the Trump administration, which dismissed the value of the treaty even as it continued to support its global verification system. As recently as last year, some Trump officials reportedly discussed the idea of resuming U.S. testing to influence Chinese and Russian behavior in future arms control talks. Congress responded by prohibiting the use of funds for nuclear test explosions for one year.

The Biden administration is not expected to try to advance support for the CTBT in the U.S. Senate, which is currently divided 50-50 between Democrats and Republicans and requires 67 votes to provide advice and consent for ratification.

The 1996 Comprehensive Test Ban Treaty propelled nuclear-weapon states to halt nuclear weapons testing, but never formally entered into force. Some UN members are trying to motivate holdout states to ratify the agreement.

North Korea Rachets Up Nuclear, Missile Activities

October 2021
By Julia Masterson

North Korea may have restarted its five-megawatt reactor, which it has historically used to produce plutonium to support its nuclear weapons program, according to a new report by the International Atomic Energy Agency (IAEA).

Whether it be nuclear weapons or missiles, North Korea is continuing to expand its military capabilities and refusing entreaties from the United States to “meet without conditions.” (Photo by Jung Yeon-Je/AFP via Getty Images)Although the reactor, located at the Yongbyon complex, was inoperative from December 2018 until July 2021, the discharge of cooling water from the reactor suggests it may now be operational, the report, issued Aug. 27, said.

The IAEA does not have an on-site presence in North Korea, but it reports annually on the country’s nuclear activities using information gathered from satellite imagery analysis and other national technical means.

North Korea’s radiochemical laboratory at Yongbyon was also operational during the last reporting period, from February to July 2021. The laboratory houses North Korea’s plutonium reprocessing facility, which is used to extract the weapons-grade fissile material from spent reactor fuel.

According to the agency’s report, “[T]he five-month timeframe is consistent with the time required to reprocess a complete core of irradiated fuel” from the five-megawatt reactor, in keeping with design information provided to the IAEA by North Korea in 1992. It is likely that North Korea’s latest reprocessing campaign involved fuel rods that were removed after the reactor was last operational, in December 2018.

North Korea has conducted three known reprocessing campaigns, in 2003, 2005, and 2009, each of which lasted for about five months.

Although North Korea appears to be continuing its plutonium production, the IAEA report suggests that the production of enriched uranium-235 has stalled. “The reported centrifuge enrichment facility was not in operation” throughout the last reporting period, the IAEA stated.

But some analysts contend that North Korea may be gearing up to boost its production of enriched uranium, as evidenced by apparent efforts to expand the enrichment hall at Yongbyon. Commercial satellite imagery reveals possible steps to construct a new outer wall at the facility, which some analysts predict could allow North Korea to rachet up its enriched uranium production by 25 percent, according to a Sept. 16 report by CNN.

Other analysts disagree, citing commercial imagery that depicts the removal of cooling units from the enrichment hall. “As proper air conditioning and system cooling is essential to the uranium enrichment process—including maintaining a consistent temperature inside the cascade halls—it is unlikely that the [uranium-enrichment plant] is currently operating,” a group of analysts wrote on Sept. 16 on the 38 North website. Any uranium-enrichment activities will remain paused until those cooling units are replaced, they estimated.

Nevertheless, North Korea’s recent nuclear activities have raised alarm. “The continuation of [North Korea’s] nuclear programme is a clear violation of relevant UN Security Council resolutions and is deeply regrettable,” IAEA Director-General Rafael Grossi wrote in the agency’s report.

Senior diplomats from Japan, the United States, and South Korea called on Pyongyang to return to talks over its nuclear and ballistic missile programs. Sung Kim, U.S. special representative for North Korea policy, met with Noh Kyu-duk, South Korean special representative for Korean peninsula peace and security affairs, and Takehiro Funakoshi, Japanese director-general for Asian and Oceanic affairs, on Sept. 14 in Tokyo. That scheduled meeting took place the day after Grossi told the IAEA Board of Governors that North Korea’s nuclear program is “cause for serious concern” and after North Korea tested new long-range cruise missiles. The U.S. envoy urged Pyongyang to “respond positively to our multiple offers to meet without preconditions.”

North Korea tested the new cruise missiles on Sept. 11 and the next day described them as a “strategic weapon” that had been developed over two years. The missiles will serve as “an effective deterrent ensuring the security of our state more firmly and overpowering powerfully the anti-[North Korean] military moves of the hostile forces,” North Korean state media reported. One of the missiles flew 1,500 kilometers.

Later in the week, Pyongyang also tested a new train-mounted ballistic missile delivery system, which state media reported could travel 800 kilometers. The testing of the new system, dubbed the Railway Mobile Missile Regiment, was overseen by a top North Korean military official.

State media said North Korean leader Kim Jong Un did not attend either missile test.


Pyongyang continues to expand its nuclear capability by testing more missiles and reportedly restarting a reactor capable of producing plutonium.

ATT Members Highlight Small Arms, Light Weapons

October 2021
By Jeff Abramson

Small arms and light weapons and stockpile management were focuses of the recent annual conference of states-parties to the Arms Trade Treaty as organizers tried to draw attention to the human harm caused by the trade and misuse of conventional weapons.

Although the formal program largely avoided discussing specific arms transfers, side events at the conference, often led by nongovernmental groups, called attention to controversial weapons deliveries to warring parties in Yemen and other conflicts that contributed to human suffering.

The conference, held Aug. 30–Sept. 3, adopted a hybrid format, with some delegates in Geneva and others joining the meeting remotely. Ambassador Lansana Gberie of Sierra Leone was the conference president.

Representatives of 86 of the treaty’s 110 states-parties were among those participating in the meeting, which took place shortly after the Taliban takeover of Afghanistan and its capture of billions of dollars in weapons provided to the Afghan government in the years after the Sept. 11 terrorist attacks. Whether concern about instability from the loss of control of so many weapons would move more countries to join the treaty is not clear. No new country has deposited legal instruments to become a state-party since 2020, before the sixth conference.

China, which acceded to the ATT in July 2020, was active at the meeting and again reiterated that Beijing does not permit arms exports to nonstate actors.


Reports on Arms Trades Decline

As this graph shows, states-parties to the Arms Trade Treaty are becoming less transparent, with fewer of them filing mandated annual reports about their authorized or actual conventional arms transfers. In 2015, 84 percent of member states filed the required annual reports; five years later, the number had dropped to 56 percent. (Source: Arms Trade Treaty Secretariat)



Among the outcomes, the conference called on the states-parties to “better utilise existing guidance and tools developed under relevant international and regional instruments on preventing the illicit trade in [small arms and light weapons] and strengthening stockpile management and security in order to prevent diversion” of weapons.

The treaty requires that countries file an initial report on national implementation practices , as well as annual reports describing authorized or actual conventional arms transfers. This reporting remains a concern for the ATT. The submission rate of annual reports has continued to decline, eroding the improvements in transparency for which treaty advocates hoped.

In 2015, 84 percent of the countries required to report on their transfers filed an annual report with the ATT Secretariat, compared to just 56 percent in 2020. Of those reports that were submitted, a growing number are being restricted for use by treaty members exclusively, rather than being made publicly available. Only 4 percent of states-parties chose private reporting for 2015, but 29 percent have done so for 2020 transfers.

As a new member, China promised to submit its initial report on time, by Oct. 3. Its first annual report is due in May 2022.

The United States, the world largest arms supplier, did not indicate whether it would again recognize its signature to the ATT or move to join the treaty. In a statement at the conference, the U.S. delegation said that a new conventional arms transfer policy “should be finalized shortly and released,” which will be used to review “the proper relationship of the United States” to the ATT. In 2019, in an effort to “unsign” the treaty, the United States informed the United Nations that it did not intend to join the ATT and had no legal obligations under its 2013 signature. Although U.S. officials have remained engaged in other treaty meetings, this was the first year it spoke formally to the annual conference since that decision. (See ACT, September 2020.)

The eighth conference will be held in Geneva on Aug. 22–26, 2022, and be led by Thomas Göbel, Germany’s representative to the Conference on Disarmament.

The annual ATT conference tried to draw attention to the human harm caused by the trade and misuse of conventional weapons.

New Action Plan Adopted on Cluster Munitions

October 2021
By William Ostermeyer and Jeff Abramson

States-parties to the pandemic-delayed review conference for the Convention on Cluster Munitions have agreed to a new five-year plan intended to “move forward towards a world free of cluster munitions.”

These unexploded cluster bomb submunitions hit a remote area of Azerbaijan near the Baku-Tbilisi-Ceyhan crude oil pipeline in October 2020 during the military conflict over the breakaway region of Nagorno-Karabakh. (Photo by Aziz Karimov/Getty Images)During Sept. 20–21, the second five-year review conference came together in a hybrid format, with some delegates meeting in person in Geneva while the rest participated remotely.

Originally scheduled to take place in Lausanne, Switzerland, in 2020 to mark 10 years since the treaty entered into force, the conference met virtually for three days in November 2020 and postponed adoption of documents in hopes that in-person meetings would be possible in 2021.

The Lausanne Action Plan adopted last month includes 50 specific measures, covering topics such as treaty universalization, stockpile destruction, clearance of contaminated lands, risk education, and victim assistance.

The conference issued a declaration expressing concern about new cluster munitions use since the 2015 action plan, specifically in Syria, Yemen, and the Nagorno-Karabakh conflict.

In the declaration, the states-parties wrote: “We underscore our obligation never under any circumstances to use cluster munitions and, in accordance with the object and provisions of the Convention, we condemn any use of cluster munitions by any actor, remaining steadfast in our determination to achieve a world entirely free of any use of these weapons.” Whether to name specific instances of cluster munitions use and how to express condemnation have been a contentious issues in recent convention meetings. (See ACT, October 2019.)

The Cluster Munition Monitor, published by the Cluster Munition Coalition, identified 360 cluster munitions-related casualties globally in 2020. One hundred and forty-two casualties occurred at the time of attacks associated with the conflict in Nagorno-Karabakh, which was a fresh cluster munitions hot spot in 2020, and from the fighting in Syria. Another 218 casualties resulted from remnants that exploded in eight countries and territories.

Some of these incidents, like those in Laos and Cambodia, occurred decades after the original attacks.

Under the treaty, countries commit to clear within 10 years cluster munitions contamination from territory they control. At the review conference, states-parties recognized Croatia, Montenegro, and the United Kingdom (for the Falkland Islands) for fulfilling this requirement, adding to eight other countries that had already done so since 2010. Afghanistan, Chile, and Mauritania received approval for extensions to this deadline.

Twenty-six states and three areas are confirmed or suspected to still have contaminated land, including 10 of the 110 states-parties to the convention. Laos, Iraq, Vietnam, and Cambodia are among the most heavily contaminated countries in the world and accounted for 95 percent of the 135 square kilometers of land cleared of cluster submunitions in 2020, according to the Mine Action Review.

The United States is not party to the convention and continued its practice of not attending formal treaty meetings.

Aidan Liddle of the UK will be president of next year’s meeting of states-parties, the 10th overall. Treaty members agreed to resume intersessional meetings, which had been discontinued, between annual formal meetings, with Liddle to set a date for one in 2022. In the future, each annual meeting will decide whether to hold intersessional meetings in the upcoming year. Iraq will hold the presidency for the 11th annual meeting, in 2023.

The review conference for the Convention on Cluster Munitions aims for progress on expanding convention membership, stockpile destruction, and clearance of contaminated lands.

South Korea Tests Submarine-Launched Missile

October 2021
By Kelsey Davenport

South Korea launched a ballistic missile from a submarine in September, making it the first country without nuclear weapons to develop that capability.

South Korean President Moon Jae-in said his country's Sept. 15 test of a submarine-launched ballistic missile was not aimed at North Korea, but "can be a clear deterrent to North Korea’s provocations." (Photo by South Korea's Ministry of National Defense)The Defense Ministry in Seoul described the launch as a success and said the missile “accurately hit its target.” The submarine-launched ballistic missile (SLBM) capability is “an important milestone” that will “contribute to realizing a strong national defense and a solid military readiness posture,” according to a Sept. 15 statement.

The SLBM test took place several hours after North Korea launched two short-range ballistic missiles from a train and four days after it tested a new land-attack cruise missile.

South Korean President Moon Jae-in, who was present for the launch, said on Sept. 15 that the test was “not a response to North Korea’s provocations.” But he noted that “the reinforcement of our missile capabilities can be a clear deterrent to North Korea’s provocations.”

The missile was tested from South Korea’s domestically built attack submarine, the Dosan An Chang-ho, which was commissioned in August. (See ACT, September 2021.) It is the first of three submarines capable of carrying six ballistic missiles that South Korea plans to deploy. South Korean news outlets reported that the submarine successfully fired an SLBM on Sept. 7, but the South Korean government has only confirmed the Sept. 15 launch. Prior to the submarine launches, South Korea conducted test launches from a submerged barge and from a ground-based test facility. The Defense Ministry said it will conduct further tests before an SLBM is deployed on the Dosan An Chang-ho.

States generally pursue SLBMs in order to provide a survivable, second-strike nuclear capability. Given that South Korea is an ally of the United States and covered by its extended nuclear deterrent, including U.S. SLBMs, it is unclear why South Korea views this capability as necessary and worth the risk of continuing to drive the missile race between North and South Korea.

Defense Department spokesman James Kirby said in a Sept. 20 press briefing that the United States is working closely with South Korea to ensure “complementary military capabilities” that are “commensurate with the continued threats that we see on the peninsula.”

Although North Korea is developing its own SLBM capability and has tested missiles from a submerged barge, officials in Pyongyang decried South Korea’s SLBM capability as detrimental to peace on the peninsula and used the test to justify its own continued missile development.

Kim Yo Jong, vice department director of the Worker’s Party of Korea, in a Sept. 15 statement questioned why Moon is “repeatedly calling for backing peace with a powerful force.” Kim, the sister of North Korean leader Kim Jong Un, criticized Moon for accusing North Korea of provocations and said South Korea has an “illogical and stupid habit of describing its act as a just one supporting peace and describing [North Korea’s] act of similar nature as one threatening peace.” North Korea’s tests are part of the country’s established self-defense plan, she said.

Pyongyang also sought to downplay the South Korean SLBM by questioning the veracity of the test. North Korea’s Academy of National Defence issued a statement Sept. 20 saying that the photos of the SLBM that South Korea released “could have deliberately been retouched” and that the missile looked more like a short-range ground-based ballistic missile that South Korea had already developed. The statement claimed that the weapon “has not yet reached the stage of being regarded as a weapon of strategic and tactical significance.”

South Korea’s SLBM test comes amid an expansion of the country’s military capabilities and continued debate over the country’s status as a non-nuclear-weapon state. In addition to the SLBM capability, South Korea has increased its military spending under Moon and invested in several new weapons systems. (See ACT, September 2021.)

Public support for South Korea developing its own nuclear weapons reached a new high in 2020 with 69 percent of the population voicing support, according to a Sept. 13 report from the Asan Institute. Since the institute began polling on this question, support for an indigenous nuclear weapons program was the lowest in 2018, when 55 percent of the population supported the idea.

In the 2020 poll, 61 percent supported reintroducing U.S. tactical nuclear weapons to the Korean peninsula, a view that one leading candidate for South Korea’s presidential election in March has also endorsed.

Hong Joon-pyo, a conservative, said that if elected he would support a nuclear sharing agreement with the United States. Lee Jae-myung, the likely candidate from Moon’s party, opposes nuclear sharing, arguing that it diminishes South Korea’s credibility in demanding that North Korea denuclearize.

In 1991, the United States removed nuclear weapons that it had based in South Korea.


The test, several hours after North Korea tested a different missile, marked South Korea as the first non-nuclear weapon state to have SLBM capability.

U.S. Mustard Agent Destroyed at Army Depot

October 2021

The last U.S. projectiles containing mustard agent at the Blue Grass Chemical Agent-Destruction Pilot Plant in Blue Grass, Kentucky, were destroyed on Sept. 4, marking the third of five destruction campaigns completed at the site.

A munitions handler guides a 155mm projectile containing mustard agent into a box to begin the destruction process at the Blue Grass Chemical Agent-Destruction Pilot Plant in Blue Grass, Kentucky. The last mustard-agent projectile was processed on Sept. 4. (U.S. Department of Defense photo)To date, about 32 percent of the chemical agents stored at Blue Grass, or about 170 tons, has been destroyed. The destruction process began in June 2019. (See ACT, July/August 2019.)

The Program Executive Office, Assembled Chemical Weapons Alternatives, which was created by Congress in 1997, is responsible for the destruction of the remaining U.S. chemical weapons stockpiles.

After signing and ratifying the Chemical Weapons Convention, the United States endeavored to destroy its approximately 3,500 tons of chemical agents. Today, only two U.S. chemical weapons destruction facilities remain operational; the rest are closed. The Blue Grass Army Depot originally stored more than 523 tons of mustard gas and nerve agents, while the Pueblo Chemical Depot, in Colorado, stored more than 2,600 tons of mustard agent.

Destruction remains ongoing at both sites. At Pueblo, 78 percent of the agents have been destroyed since the process began in March 2015.—JULIA MASTERSON

U.S. Mustard Agent Destroyed at Army Depot

U.S. Advances Nuclear Security Goals

October 2021

The U.S. National Nuclear Security Administration (NNSA) took domestic and international strides toward securing and eliminating nuclear materials over the past two months.

The NNSA, a semiautonomous agency within the Energy Department, on Aug. 27 awarded $37 million to the Wisconsin-based company NorthStar Medical Technologies to advance the domestic supply of a vital medical isotope, molybdenum-99 (Mo-99), that is used daily in tens of thousands of medical procedures and cancer diagnoses.

In the past, U.S. medical facilities obtained Mo-99 from foreign sources that primarily produced the isotope by way of highly enriched uranium (HEU), which can be used to fuel nuclear weapons and thus presents a nuclear proliferation risk if stolen or diverted. Congress called on the NNSA in 2012 to establish the Mo-99 Program in order to promote a reliable domestic supply of the isotope and to reduce the potential use of HEU for nuclear weapons proliferation.

In addition, the NNSA launched on Aug. 30 the RadSecure 100 initiative aimed at enhancing domestic radiological security. Through partnerships with local businesses, medical centers, and law enforcement, this initiative aims to remove high-priority radioactive material from some U.S. facilities while boosting security at the remaining facilities in 100 U.S. cities. It will also focus on ensuring secure transportation of high-risk radioactive sources.

Overseas, the United States and Norway cemented a plan to fully eliminate Norway’s HEU by blending it down to low-enriched uranium. Down-blending the concentration of HEU to a level below 20 percent uranium-235 prevents its weaponization. The project will begin in 2022, announced Norwegian Minister of Trade and Industry Iselin Nybø on Sept. 1.

This agreement “lays an important foundation for Norway to get rid of its nuclear weapons-usable material,” said Nybø. “We are thus delivering at home what Norway and the United States have worked towards globally for several years: reducing the use of HEU in the civilian sector.” Once the down-blending is completed, Norway will become the 34th country to be considered HEU free.—MARY ANN HURTADO

U.S. Advances Nuclear Security Goals

Preserving the Nuclear Testing Taboo

September 2021
By Daryl G. Kimball

For the first five decades of the nuclear age, nuclear weapons test explosions were the most visible symbol of the dangers of nuclear weapons and the omnipresent threat of nuclear war. Most of the 2,000-plus nuclear test blasts were used to confirm new warhead designs and develop more deadly weapons systems, which in turn fueled a dangerous spiral of global nuclear competition.

The Nevada Test Site was the location of 928 of the United States 1,054 nuclear weapons tests. The last U.S. nuclear test was conducted on September 23, 1992. President Clinton signed the CTBT on Sept. 24, 1996. Photo by Nevada National Security Site.Nuclear testing also produced radioactive contamination, not only immediately downwind from the test sites but globally. One independent study from 1991 estimates that nuclear testing led to nearly half a million additional cancer fatalities worldwide through the year 2000.

But since the conclusion of the Comprehensive Test Ban Treaty (CTBT), nuclear testing has become taboo. The treaty, which opened for signature on Sept. 24, 1996, has near-universal support with 185 signatories, including the five original nuclear testing states. All CTBT states agree that the treaty prohibits “any nuclear weapons test explosion, or any other nuclear explosion” no matter what the yield.

Even those nuclear-armed states that have not signed or not ratified the CTBT, including India, Israel, and Pakistan, observe nuclear testing moratoriums. Only one country has conducted nuclear test explosions in this century, and even that country—North Korea—halted nuclear testing
in 2017.

The CTBT has achieved its core goal: ending all nuclear testing. By this measure, the treaty is one of the most successful agreements in the long history of nuclear arms control and nonproliferation. Without the option to conduct nuclear tests, it is more difficult, although not impossible, for even the most advanced nuclear states to develop, prove, and field new warhead designs. The CTBT is a powerful brake on vertical and horizontal nuclear proliferation.

But we cannot take the nontesting norm for granted. It was only a year ago that some senior Trump officials suggested the United States should resume nuclear testing for the first time in 28 years to intimidate Russia and China. The treaty’s onerous entry-into-force requirement and the failure of eight holdout states, including the United States and China, to ratify the treaty has delayed its full implementation. As a result, the door to nuclear testing remains ajar.

Given the high stakes, there is no room for complacency from the U.S. and other governments, which should understand the importance of preventing the spread of ever more lethal nuclear weapons. States-parties to the nuclear Nonproliferation Treaty (NPT) should strengthen their call to action on the CTBT at the upcoming NPT review conference.

President Joe Biden, a long-time CTBT advocate, should reaffirm U.S. support for the treaty and its entry into force. As he declared in 2020, “We have not tested a [nuclear] device since 1992, we don’t need to do so now. A resumption of testing is more likely to prompt other countries to resume militarily significant nuclear testing and undermine our nuclear nonproliferation goals.”

As importantly, the Biden administration needs to pursue the adoption of additional voluntary measures designed to detect and deter possible low-level, clandestine nuclear testing by the major nuclear powers.

Today, the United States, China, and Russia—all CTBT signatories—continue to engage in weapons-related activities at their former nuclear testing sites. Only France has permanently closed its former test site. Although the treaty’s International Monitoring System is operational and far more effective than originally envisioned, very low-yield nuclear weapons test explosions can still be difficult to detect without on-site monitoring equipment or on-site inspections.

In May 2019, the director of the U.S. Defense Intelligence Agency charged that “Russia probably is not adhering to its nuclear testing moratorium in a manner consistent with the ‘zero-yield’ standard outlined in the [CTBT].” In April 2020, the State Department claimed that, “during the 1995–2018 timeframe, Russia probably conducted nuclear weapons-related tests” at Novaya Zemlya. In April 2021, the State Department repeated the claim without specifying when such activities may have occurred.

Russia, which has signed and ratified the CTBT, has vigorously denied the charge and pointed to the failure of the United States to ratify the treaty.

If the U.S. government takes its own intelligence reports and arms control compliance seriously, it should develop a proposal for mutual confidence-building measures, such as notification and exchange of information about certain experiments and the installation of additional sensory devices.

Russia suggests such measures should only be pursued after entry into force. That is an unhelpful position. If Russia truly supports entry into force of the CTBT, it could leverage progress by agreeing to implement these voluntary, reciprocal transparency measures after the United States ratifies the CTBT.

A quarter century after it was negotiated, the CTBT has brought an end to nuclear testing. But to keep a de facto global nuclear test moratorium intact, friends of the CTBT will need to do more to rejuvenate efforts to achieve its entry into force and reinforce the taboo against nuclear testing.

For the first five decades of the nuclear age, nuclear weapons test explosions were the most visible symbol of the dangers of nuclear weapons and the omnipresent threat of nuclear war.

The CTBT at 25 and Beyond

September 2021
By Francesca Giovannini

This year marks a major milestone for the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The multilateral body was founded to support implementation and compliance with the Comprehensive Test Ban Treaty (CTBT), which established a prohibition on all nuclear weapons test explosions anywhere. After a protracted and combative election process against incumbent Lassina Zerbo, Australian candidate Rob Floyd prevailed with a convincing majority; and as of August 1, he has taken over as the CTBTO’s fourth executive secretary.

View of infrasound station array at infrasound station IS49, Tristan da Cunha, U.K. (Photo by CTBTO )This change in leadership is expected to breathe new ideas into the management of the organization and could open new avenues for cooperation with countries in the Asia-Pacific region and beyond. At the same time, Floyd and the organization face daunting challenges during a year that also marks the 25th anniversary of the CTBT’s opening for signature in 1996. Although the treaty has successfully halted nuclear testing for a quarter-century, the door to renewed testing and, with it, an accelerated expansion of global nuclear weapons capability remain open because the treaty has not yet formally entered into force.

Despite political and legal uncertainty, the CTBTO and its member states have shown remarkable ingenuity in establishing a successful global monitoring network—the International Monitoring System (IMS)—of unprecedented scale and sophistication. The system relies on superb and still unsurpassed technical capabilities for monitoring and verifying the global nuclear test ban. Nevertheless, serious technical and political challenges to the long-term sustainability of the organization and the monitoring system are slowly emerging. Consequently, although this would be undesirable and politically costly, the international community should consider taking steps to decouple the IMS from the treaty’s fate in order to maintain and expand on the extraordinary technical investments that the monitoring system represents.

Indispensable but Ignored for Too Long

For 25 years, experts in academia and the nuclear policy community have written and argued about the CTBT’s indispensable role as an instrument for preventing nuclear proliferation, including the geographical spread of nuclear weapons to additional states and the qualitative improvement or expansion of existing nuclear weapons arsenals. Nuclear testing is crucial in the acquisition of nuclear weapons and in the improvement of such weapons.1 Because of the vital role played by the CTBT in nuclear nonproliferation and disarmament, efforts to achieve its entry into force have gone in all directions, from public outreach initiatives to advocacy campaigns and youth mobilization. These laudable activities have helped to elevate the treaty’s visibility and involve a new generation of arms control scholars in the organization’s mission. Yet despite all efforts, the treaty remains in a legal vacuum.

One complication is the CTBT ratification process, which is unique and obtrusive. It requires ratification by 44 countries (the so-called Annex II states) that at the time of the negotiations were deemed nuclear capable. Today, eight of those countries—China, Egypt, India, Iran, Israel, North Korea, Pakistan, and the United States—have still failed to ratify the treaty and thus are preventing its entry into force.

Each of these countries faces distinct security challenges, operating within specific security dynamics marked by military, technological and ideological entanglements (table 1).

Throughout the 1990s and the first decade of the 2000s, advocacy campaigns promoting the treaty’s entry into force focused mostly on building political coalitions within the U.S. Senate,2 moved by the untested but rational belief that ratification by the United States would incentivize other holdout countries to follow suit.3 That assumption might have sounded plausible then, but it appears far too simplistic today in a time of great-power competition, shifting regional loyalties, and a revival of a global arms race. Although U.S. ratification would very likely elicit positive support from other Annex II countries, it will not be sufficient to bring the treaty to the finish line.

The uncertain destiny of the CTBT has reinforced the view among many non-nuclear-weapon states that incremental strategies to advance nuclear disarmament, such as the CTBT, will inevitably continue to be subjected to power procrastination games among nuclear-weapon states and will never be able to achieve a world without nuclear weapons.

Other CTBT advocates counter that even though the CTBT has not formally entered into force, it has succeeded in bringing about a global nuclear testing halt, which is the central purpose of the treaty, on a de facto basis. They note that the only country that has clearly engaged in nuclear explosive testing in this century is North Korea, and for now, even that country has halted nuclear explosive testing. These advocates caution that the taboo against testing cannot be taken for granted and that, until such time as the CTBT enters into force, thus allowing for short-notice on-site inspections, or new confidence-building measures are established, concerns about clandestine nuclear test explosions, particularly at low yields, will linger.4

These narratives capture tangible fears and disillusionment among many countries squeezed between a new global arms race and the paralysis of multilateral arms control and disarmament institutions. They also reinforce a growing sense of doubt regarding the CTBT’s fate.

Another, not so visible yet equally important concern relates less to the treaty’s entry into force and more to the sustainability of the actual organization and the monitoring system it has created. As the treaty’s entry into force lags, critical questions surface. How long will the international community support the work of an organization operating in the absence of a legally binding treaty? How long will member countries pour resources into a monitoring system that, at best, will continue to operate provisionally for the foreseeable future? How long will the IMS remain capable of attracting top-notch scientific and technical talent?

The International Monitoring System

The IMS is an impressive and unmatched global monitoring system with features that make it a marvel of science diplomacy and international technological cooperation. It is the only global verification system concurrently employing four main technologies: radionuclide, which detects atmospheric nuclear explosions and determines the source of underwater and underground nuclear explosions; seismic, which detects underground explosions; hydroacoustic, which detects underwater explosions; and infrasound, which focuses on the atmosphere (table 2).

The need to adopt a multitude of technologies stemmed from the treaty’s broad mandate to ban all nuclear explosions by everyone, everywhere, and in all environments—underground, underwater, and in the atmosphere. Most treaties are not so comprehensive.

The work is carried out by a world-class scientific team of experts located in Vienna and at the CTBTO monitoring stations and technological hubs across Africa, Asia, South America, and beyond.

Although it is 92 percent complete, the system is operating on a provisional basis. That means that data originating from IMS operating stations are transmitted to the CTBTO’s Vienna headquarters through a satellite communications network. Once there, data is analyzed and screened by analysts with the CTBTO International Data Centre. Their findings are sent back to signatory states. Because of the provisional nature of the system, member states transmit the raw data on a voluntary basis. If suspicious activities are detected in the analysis of the data, members cannot make use of the treaty-enshrined follow-up mechanisms, such as consultations, clarification, and request for on-site inspections.

Regardless of its value, in the absence of a binding treaty, the provisional standing of the IMS raises important legal questions. As Masahiko Asada, professor of international law at Kyoto University, has remarked, “This presents a really unique situation in legal terms. Both the construction of the IMS network and its provisional operations have been carried out without the CTBT entry into force. What then is the legal basis for these developments?”5 For years, Article IV of the CTBT has been assumed to provide the authority for establishing the IMS in the absence of a legally binding treaty by stating that “[a]t the entry into force of this treaty, the verification regime shall be capable of being the verification requirements” of the CTBT.

Radionuclide Station RN73 Palmer Station Antarctica. (Photo by CTBTO)This formulation allowed the organization to establish the IMS in preparation for the treaty’s entry into force. Construction began immediately, propelled by a sense of optimism that the treaty would enter into force without delay. After all, on September 24, 1996, the United States was the first nation to sign the CTBT. President Bill Clinton cast himself as an active promoter of the treaty, which he called “historic” and reflective of a “decades-old dream that no nuclear weapons will be detonated anywhere on the face of the earth.” At a time of U.S. economic and military supremacy, many believed that, despite significant political hurdles,6 CTBT ratification was within reach.

To sustain momentum behind the ratification process, member states poured money into developing the IMS. By the time a nascent network of stations began to operate, however, the geopolitical landscape had changed dramatically. India and Pakistan conducted nuclear test explosions in 1998, the U.S. Senate rejected ratification in 1999, and the war in Kosovo had soured relations between Russia and the United States. Consequently, the build-up of the IMS slowed, but was never halted.

Two main drivers kept momentum going: First, many countries, including the United States, came to appreciate the value of the monitoring system as a provider of global data that national technical means could not match. Second, treaty supporters believed that by demonstrating the effectiveness of the system, negotiations on bringing the treaty into force would be revamped. As Zerbo remarked in 2016, “There is no better way to convince people to ratify the CTBT than showing them that they have a sustainable international monitoring system and the verification regime that can serve their purpose.”7

Despite its provisional status, the IMS has been consistently praised for exceeding expectations in detecting capabilities and enabling cross-domain scientific collaboration. The UN Security Council has officially recognized the effectiveness of the monitoring system and its role in enhancing peace and security by stating that “even absent entry into force of the treaty, the monitoring and analytical elements of the verification regime…contribute to regional stability as a significant confidence-building measure, and strengthen the nuclear non-proliferation and disarmament regime.”

In addition, the system has spurred enthusiasm for science and technology cooperation around the world and has democratized access to scientific data and know-how in unprecedented ways. Nations hosting IMS stations have concrete incentives to invest in their national scientific capacities to operate and maintain the stations and to benefit from the data. From Africa to Asia, a new global scientific community has emerged largely because of the IMS and the extensive investments by CTBTO in capacity building to sustain and expand the pool of scientific talent.

The IMS also represents a towering achievement in the democratization of science. As then-CTBTO Executive Secretary Tibor Tóth noted,

[T]he CTBT verification regime is a truly democratic and participatory system. The data and products of the CTBTO Preparatory Commission are made available to every signatory state, regardless of size or wealth or technological prowess, making sure that transparency is not limited to the few states who possess the necessary technical and financial resources. The credibility of our verification system does not only reside in its technical performance but also in the open and equal access of all signatory states.8

Challenges Facing the IMS

Although the capabilities of the IMS are often publicly praised, its emerging challenges are discussed in closed-door meetings among diplomats concerned about the future of the treaty and the organization. Like any technological system, to remain effective the IMS needs to attract and retain scientific talent, identify emerging technologies that could hinder or strengthen its operational capabilities, and attract the necessary resources to keep functioning even if only on a provisional basis.

These challenges would be complex to manage and address for any technological system, but the enduring legal limbo of the treaty could fatally undermine the ability to address these inherent vulnerabilities.

The race to secure scientific talent, for instance, is accelerating in all technical domains and across all continents. It is made more difficult by the rise in technonationalism and the pursuit of primacy and domination in strategic sectors, including artificial intelligence and space. Unsurprisingly, given the level of specialization required, the CTBTO has struggled to fill key technical positions and retain highly qualified experts as several national delegations have apprehensively noted.

As Mitsuru Kitano, Japan’s ambassador to the CTBTO, remarked, “[W]e appreciate the Provisional Technical Secretariat’s [PTS] continuous efforts to improve the system of recruitment. At the same time, we are concerned about the fact that there is still the issue of vacancies. It is essential to fill the vacancies as early as possible to provide a sound basis for a sustainable working environment for the organization to fulfil its mandate. We hope that the PTS will take appropriate measures to improve the situation.”9

Namibia’s Simon Madjumo Maruta, the representative of the Non-Aligned Movement (NAM), further underscored that the NAM, “while recognizing the difficulties faced by the PTS, reiterates its principled position that striving for equitable geographic distribution as well as gender balance in the overall composition of the PTS is of utmost importance. The [NAM] is encouraged by the renewed impulse given by the Executive Secretary to addressing the Human Resources issues that have been outstanding these past years.”10

There is also the threat of the IMS losing its technological edge. Because the treaty text is concluded but not entered into force, no technical changes or modifications can be made to the IMS design at this stage, including the adoption of new technologies that could make operating the system smarter and more cost effective. Meanwhile, national technical means continue to evolve and mature, potentially overtaking the IMS and making it redundant. For example, at the time of the treaty negotiations, satellite technology was deemed too costly and therefore not listed among IMS technologies. Today, the commercial satellite industry is flourishing, making the technology not only viable and accessible but ubiquitous and extraordinarily cheap. Nuclear expert George Perkovich once noted that the costs of verifying the transition to a world free of nuclear weapons would be substantial, exceeding initial forecasts. That is also proving true with the CTBTO. In fact, according to CTBTO sources, the costs incurred to build and run the IMS nears $1 billion, far exceeding initial estimates of roughly $80 million.

Most importantly, although initial investments to build the IMS might not have been especially high the costs of maintenance remain largely underestimated or, worse, unbudgeted. Building IMS stations around the world initially generated much enthusiasm, political visibility, and media attention. Yet, these stations need to be maintained and repaired, and the political fanfare that once accompanied their construction has waned. That is because it is relatively easier to sell something new than to convince domestic constituencies of the continued value of spending money to underwrite a treaty that has no viable prospects of entering into force soon.

Experts associated with the CTBTO's international system for monitoring nuclear testing gather gas samples from the ground to be examined for traces of the noble gas Argon as evidence of an underground nuclear explosion. (Photo by CTBTO)The COVID-19 pandemic has worsened the situation, making it imperative for countries to be more frugal about their own investments. As a result, negotiations to secure the funding to repair and maintain operating stations are becoming difficult and compromises more difficult to reach. In the most recent CTBT report, Zerbo encouraged CTBTO member-states to embrace “a holistic approach to establish and sustain the complex global network of the IMS. This is achieved through testing, evaluating, and sustaining what is in place and then further improving on this. Sustainment covers maintenance through necessary preventive maintenance, repairs, replacement, upgrades, and continuous improvements to ensure the technological relevance of the monitoring capabilities.”11

Decoupling the IMS From the Treaty

Throughout the past decade, as the prospect for the treaty’s entry into force became more remote, proposals emerged to shake up the status quo and revive the political process. All of them are incomplete, possibly implausible, and unquestionably suboptimal, betraying the ultimate spirit that inspired the international community to negotiate the CTBT. Nonetheless, these ideas reveal a sense of urgency and pragmatism as CTBT proponents desperately seek to prevent institutional paralysis from turning into institutional collapse and a multilateral crisis.

A few of the proposals have sought ways to bypass the cumbersome ratification process. In an excellent analysis on the prospects for rescuing the treaty, John Carlson, former director-general of the Australian Safeguards and Non-Proliferation Office, suggests four possible paths. They are: negotiate a new treaty, replicate the existing CTBT but with revised entry-into-force provisions, waive Annex II by adopting a protocol or a resolution by which ratifying states declare the CTBT is in force and waive the Annex II provision, or agree to have part of the CTBT enter into force provisionally, for instance, some technical and verification measures, pending the ratification by all Annex II states.12

These options have been rejected by powerful states, including the Russian Federation and the NAM members, because they fundamentally undermine the “comprehensive nature” of the CTBT by failing to bind nuclear-weapon states that do not join the treaty. Such options would thus perpetuate power asymmetries and the unfair bargain between the nuclear haves and the nuclear have-nots.

As the situation continues to stagnate, another approach that focuses more narrowly on the survivability of the monitoring system deserves consideration. Until the treaty enters into force, the IMS could be decoupled from the treaty and established as a separate international body, namely an independent, international observatory on nuclear testing, committed to certain specific principles. One principle would be neutrality in data collection and delivery of the analysis. The other principle would be inclusive, international representation with governmental institutions and nongovernmental organizations (NGOs) involved in securing the necessary technical and human resources.

Observatories have historical roots dating to 16th century Europe. They have traditionally been spaces of science and technology discoveries but also avenues for public engagement and social dialogue.

There are several advantages to this approach. It would allow more flexibility in introducing and adopting new technologies and enable the observatory to remain abreast of technical changes in nuclear verification. It would foster greater collaboration and elicit more direct involvement by academia, the private sector, and NGOs. It would promote data sharing among scientific institutions and would elevate further the importance of the IMS as a global hub for scientific and technological advancements in nuclear test verification. Finally, it would continue to serve as a technical avenue for cooperation among nuclear-weapon states invested in the establishment and maintenance of the IMS.

There is no question that such a proposal is at best suboptimal and at worst risky and undesirable. Decoupling the IMS from the treaty could undermine its symbolic and political standing vis-à-vis many of the countries that invested in the treaty in the first place. It also could set a dangerous precedent. Ratified treaties are a fundamental pillar of the modern, rule-based global order. Shifting to an easier yet less permanent cooperative mechanism could bring further instability and opportunism to an already unpredictable international environment. Finally, the proposal could turn into an observatory for rich nations only, thus further losing the universality that the treaty aspires to achieve.

Yet, the trade-offs that the international community might soon be forced to face between a treaty in limbo and a fully operational monitoring system capture a broader and more worrisome trend. In the face of growing global competition, achieving the entry into force of universal treaties will become increasingly difficult and unlikely. Hence, regional and global nuclear cooperation will have to take different forms from the ones they have taken in the past. Compromises will have to be made and suboptimal solutions, however distasteful and imperfect, will have to be accepted.

As the international community considers its options for defending, strengthening, and sustaining the CTBT regime, pressure is certain to build from those who argue that the treaty is not going anywhere and that no major initiatives are needed to secure its entry into force. Given that the CTBTO has matured into an effective operation over the past 25 years, the world will be able to muddle through uncertain times for another quarter of a century, or so that argument goes. That risky approach assumes member states will somehow continue to have the political will to stick with this treaty to a fading finish line. It also ignores the likelihood that new priorities will arise, that emergencies will take precedence, and that political support for the CTBT and financial support for the effective operation of the IMS will dwindle.

No path will be pain free. The international community is operating in a difficult period in which pragmatism should prevail and investments must be protected. For those who have been working on the CTBT for years, this observatory proposal might not be welcome, but the available alternatives could be much worse.


1. Sergio Duarte, “The Future of the Comprehensive Nuclear-Test Ban Treaty,” UN Chronicle, n.d., https://www.un.org/en/chronicle/article/future-comprehensive-nuclear-test-ban-treaty.

2. Daryl G. Kimball, “Learning From the 1999 Vote on the Nuclear Test Ban Treaty,” Arms Control Today, October 2009, https://www.armscontrol.org/act/2009-10/learning-1999-vote-nuclear-test-ban-treaty.

3. Rizwan Asghar, “The Future of the CTBT,” CTBTO Spectrum, No. 22 (August 2014), p. 17,

4. Daryl G. Kimball, “U.S. Claims of Illegal Russian Nuclear Testing: Myths, Realities, and Next Steps,” Arms Control Association Policy White Paper, August 16, 2019, https://www.armscontrol.org/sites/default/files/files/PolicyPapers/ACA_PolicyPaper_CTBT_DK_2019.pdf.

5. Masahiko Asada, “CTBT: Legal Questions Arising From Its Non-entry Into Force,” Journal of Conflict and Security Law, Vol. 7, No. 1 (April 2002): 104.

6. Barbara Crossette, “UN Endorses a Treaty to Halt All Nuclear Testing,” The New York Times, September 11, 1996, https://www.nytimes.com/1996/09/11/world/un-endorses-a-treaty-to-halt-all-nuclear-testing.html.

7. Andreas Persbo, “Compliance Science: The CTBT Global Verification System,” Non-Proliferation Review, Vol. 23, Nos. 3-4 (2016): 1.

8. “Statement of the Executive Secretary, Mr. Tibor Tóth, on the Occasion of the Scientific Symposium,” August 31, 2006, https://www.ctbto.org/fileadmin/content/reference/symposiums/2006/0831tothspeech.pdf.

9. Mitsuru Kitano, statement at the 45th session of the CTBTO, November 16, 2015, https://www.vie-mission.emb-japan.go.jp/itpr_en/PC45_statement_EN.html.

10. Simon Madjumo Maruta, statement on behalf of the Group of 77 and China at the 46th session of the CTBTO, June 14, 2016, https://www.g77.org/vienna/wp-content/uploads/2019/03/CTBTOMatters_46th-Session-of-the-CTBTO-PrepCom-13-17-June-2016.pdf.

11. Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), “Advancing Verification Capabilities: Annual Report 2019,” September 2020, p. 12, https://www.ctbto.org/fileadmin/user_upload/pdf/Annual_Report_2019/English/00-CTBTO_AR_2019_EN.pdf.

12. John Carlson, “Comprehensive Nuclear-Test-Ban Treaty: Possible Measures to Bring the Provisions of the Treaty into Force and Strengthen the Norm Against Nuclear Testing”, VCDNP, March 2019, https://vcdnp.org/ctbt-possible-measures-to-bring-the-provisions-of-the-treaty-into-force-strengthen-the-norm-against-nuclear-testing/


Francesca Giovannini is the executive director of the Harvard Belfer’s Initiative on Managing the Atom and the research director of the Nuclear Deterrence Research Network funded by the MacArthur Foundation. She is an adjunct associate professor at the Fletcher School of Law and Diplomacy. Prior to her Harvard appointment, she served as strategy and policy officer to the executive secretary of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO), based in Vienna. In that capacity, she oversaw a series of policy initiatives to promote CTBT ratification as a confidence-building mechanism in regional and bilateral nuclear negotiations.

Although the CTBT has halted nuclear testing for a quarter- century, the door to renewed testing and an expansion of global nuclear weapons capability remains open because the treaty has not yet formally entered into force.

North Korea and the Proof of Nuclear Adherence

September 2021
By Ankit Panda and Toby Dalton

In May 2021, the Biden administration announced its intention to pursue a “calibrated, practical approach that is open to and will explore diplomacy” with North Korea. The intention was to distance its approach from those of President Joe Biden’s two immediate predecessors. As White House spokesperson Jen Psaki emphasized, “[O]ur policy will not focus on achieving a grand bargain, nor will it rely on strategic patience.”1

In a subtle but potentially transformative decision, the administration also signaled it would seek “practical progress” with North Korea in ways that could increase “the security of the United States, our allies, and deployed forces.” This statement acknowledges the obvious: that U.S. and allied interests could be served by measures that fall short of the complete denuclearization of the Korean peninsula, which remains a long-term objective.

Although the administration does not use the phrase “arms control” in describing its North Korea policy, achieving any “practical progress” would require limiting the quantitative growth and qualitative improvement of North Korea’s nuclear capabilities. Among the many difficult issues that U.S. negotiators would have to address with Pyongyang, if and when negotiations resume, is how North Korean compliance with such limits could be verified and monitored.

Practical Verification for Practical Progress

In the past, verification has proved a source of considerable tension when implementing nuclear agreements with North Korea. Under the 1994 Agreed Framework, long before North Korea gained the range of nuclear capabilities it has, U.S. inspectors successfully obtained on-site access to suspected sites2 but only after protracted negotiation with North Korean officials. The North’s fundamental mistrust of the United States, other major powers, international organizations, and the entire, highly intrusive verification process complicated these efforts.3 In late 2008, Pyongyang’s misgivings about a verification protocol to the 2007 six-party talks4 gave way to a slow-simmering crisis that eventually boiled over, resulting in the expulsion of International Atomic Energy Agency (IAEA) monitors in April 2009. A month later, North Korea carried out its second nuclear test.5

Despite this, Pyongyang understands that verification and monitoring are a sine qua non of any potential nuclear agreement. For instance, after the Trump administration rejected North Korea’s proposed concessions at the February 2019 summit in Hanoi, North Korean Foreign Minister Ri Yong Ho emphasized that Pyongyang’s offer to dismantle “nuclear material production facilities in the Yongbyon area”6 entailed doing so “in the presence of U.S. experts.” The Pyongyang Declaration of September 2018,7 agreed between South Korean President Moon Jae-in and North Korean leader Kim Jong Un, similarly included a clause whereby the North would dismantle its Dongchang-ri (or Sohae/Yunsong)liquid-propellant engine test stand “under the observation of experts from relevant countries.”8Fuel Rod Fabrication Plant and other facilities at North Korea's Yongbyon nuclear complex in 2007.  (Image: Google Earth, © 2021 Maxar Technologies)

By 2021, the Fuel Rod Fabrication Plant had been renovated and expanded. Nuclear expert Olli Heinonen wrote for the 38North website that commercial satellite imagery shows that since 2009 "substantial changes" have taken place "indicating the gradual repurposing of this facility." Now known as the Uranium Enrichment Plant, it "has become the backbone of North Korea’s ability to produce fissile material for nuclear weapons," he wrote. (Image: Airbus Defence & Space, 38 North, and “Pleiades © CNES 2021, Distribution Airbus DS”)

Now that Biden administration officials have unambiguously stated9 that denuclearization is a “long-term objective” rather than the singular and immediate goal demanded by President Donald Trump, U.S. policymakers should begin working on creative, practical, perhaps even unorthodox approaches to verification and monitoring.

The U.S. government has considerable experience and expertise in monitoring and verifying nuclear and missile restraints. Yet, the shift in assumptions implied by the Biden policy, from a one-shot denuclearization agreement to incremental steps, means that verification experts will confront unprecedented challenges that will require new tools and approaches. If the administration does not plan for these situations now, negotiators may be inhibited in the types of progress they may be able to clinch when negotiations resume.

North Korea is likely to reject orthodox and invasive verification measures, such as “anytime, anywhere inspection,” at least at the beginning of a denuclearization process. With an ever-growing arsenal that includes an estimated 20 to 60 nuclear warheads and an expansive inventory of nuclear delivery systems, Pyongyang’s negotiating leverage is far greater than it has been in the past. As a result, “practical progress” is highly unlikely to begin with the return of IAEA inspectors to the Yongbyon nuclear complex or, more ambitiously, with on-site inspections at missile operating bases that North Korea has refused to acknowledge.

Even so, negotiators can and should seek to maximize the verifiability of any potential agreements. That will be critical to the political viability of these agreements and will ensure that progress toward denuclearization is observable and measurable. In this way, verification and monitoring will serve as a means toward the ultimate goal of denuclearization, rather than an end in themselves.

Novel Approaches to Verification and Monitoring

As the Biden administration began its North Korea policy review, the Carnegie Endowment for International Peace convened a group of international technical experts to study potential new approaches to verification and monitoring. Part of the group analyzed novel approaches to verifying declared items in a potential future agreement, such as missiles, missile launchers, fissile material, and, eventually, nuclear warheads. Others explored conceptual, technical, and methodological approaches to building a layered monitoring system. This included an examination of probabilistic verification and compliance assessment, the applicability of open-source intelligence tools, and the promise of a nodal monitoring system.

The group also considered approaches to an export-import regime that might limit North Korea’s ability to procure critical goods for its weapons of mass destruction programs or to sell such items to third countries. Finally, despite the considerable differences between the cases of North Korea and Iran, the group assessed the applicability of some of the innovative verification and monitoring provisions that were included in the 2015 Joint Comprehensive Plan of Action with Iran.10

These studies offer some suggestions for how the Biden administration could seek to verify and monitor prospective practical agreements with North Korea, such as a missile freeze, fissile material controls, and limitations on deployed missiles.

Missile Test Freezes and Beyond

North Korea has made important qualitative strides in its missile capabilities in recent years, particularly under Kim, and now possesses several types of missiles assessed to be nuclear capable. There is some precedence for Pyongyang to agreeing to negotiated, albeit temporary, missile restraints. With the goal of supporting then-ongoing diplomacy, the Berlin agreement in September 1999 formalized a nearly seven-year-long freeze on long-range missile tests by North Korea. The Leap Day deal in February 2012 established a moratorium on long-range missile launches, although it collapsed in less than two months over differences between the United States and North Korea on whether it covered space launches. Most recently, during the Trump administration’s diplomatic outreach with North Korea in 2018 and 2019, Kim voluntarily announced a moratorium on long-range missile testing, which has since been rescinded.

By 2021, the Fuel Rod Fabrication Plant had been renovated and expanded. Nuclear expert Olli Heinonen wrote for the 38North website that commercial satellite imagery shows that since 2009 "substantial changes" have taken place "indicating the gradual repurposing of this facility." Now known as the Uranium Enrichment Plant, it "has become the backbone of North Korea’s ability to produce fissile material for nuclear weapons," he wrote. (Image: Airbus Defence & Space, 38 North, and “Pleiades © CNES 2021, Distribution Airbus DS”)Pyongyang has never submitted to intrusive verification and monitoring of its missile capabilities and missile-related industrial complex, so whatever the form of future negotiations, this issue is sure to be contentious. Even so, missile freeze agreements could take various forms, with implications for how they might be verified.

By any measure, a test freeze remains the easiest objective for negotiators. It could cover the flight testing of fully assembled missile systems and the testing of certain subsystems, including static ground testing of rocket boosters. Both types can be verified remotely through the use of U.S. space-based infrared sensors, which are optimized for the detection of the hot plumes associated with missile launches and ground testing. North Korean testing of nuclear-capable cruise missiles, however, may present certain problems for space-based monitoring. Cruise missiles that have been tested are not known to be nuclear capable, but Kim has indicated that a new intermediate-range cruise missile under development may be nuclear capable.

The value of a test freeze decreases as North Korea generally becomes more sophisticated and experienced with missile technologies. Under a test freeze, for instance, there would be no restraints on North Korea producing more missiles of types that have already been proven or attempting other qualitative upgrades to existing missiles, such as improved guidance.

Because of this limitation, policymakers may choose to seek two considerably more ambitious objectives: a freeze on missile production or on missile deployments. Neither has any precedent with North Korea, but each would represent marked progress toward subsequent denuclearization steps. A production freeze would cap the growth of North Korea’s nuclear force. A deployment freeze would limit and perhaps, over time, degrade the size and readiness of North Korea’s deployed arsenal. Both freezes could be observed with some confidence via remote sensing capabilities, but verification and monitoring would benefit considerably from on-site inspections or other types of intrusive on-the-ground monitoring.

Although freezes on production and deployment would be infinitely preferable, a freeze on testing, implemented properly, could facilitate the conditions for further diplomatic progress with North Korea and open the door to the more complex verification arrangements required to support production and deployment freezes.

Applying Flexible Safeguards

Traditionally, U.S. and international efforts to restrain and reverse North Korea’s nuclear ambitions have focused on freezing the production of weapons-grade fissile material, as in the 1992 North-South Joint Declaration on Denuclearization of the Korean Peninsula, the 1994 Agreed Framework, and the agreements of 2005 and 2007 stemming from the six-party talks. Although the IAEA monitored the freezes, its activities fell well short of applying traditional IAEA safeguards to relevant facilities at the Yongbyon complex.

IAEA safeguards remain the standard for verifying that nuclear materials are not diverted to weapons use. Yet, future attempts to monitor and safeguard North Korean facilities at Yongbyon and elsewhere need not begin with demands for complete access to these facilities, records, and, most critically, nuclear material. Instead, utilizing traditional safeguards tools through more flexible and gradual approaches to monitoring negotiated fissile material controls would initially make sense.

For example, rather than insisting that North Korea present a complete declaration of nuclear materials to be verified, a more practical agreement could stipulate a piecemeal approach involving the monitoring of specific facilities, such as the uranium-enrichment hall at Yongbyon; of materials, such as separated plutonium, not in weapons form; or stages of the fuel cycle, such as uranium conversion. Safeguarding declared waste materials, such as spent fuel, could also serve as a useful, early stepping-stone to more comprehensive safeguards.

Meanwhile, monitoring could initially be focused on verifying the nonoperational status of facilities or the presence of specific materials. As North Korea complied with such limited safeguards activity, more intrusive access could become feasible. A flexible approach along these lines would avoid the problem of placing high hurdles, such as a demand for a complete declaration or full access, too early in a negotiation, yet would still permit the IAEA to begin to assemble a more complete picture of the North Korean nuclear enterprise.

Broken seals that had been used to tag nuclear equipment under International Atomic Energy Agency safeguards. North Korea ceased cooperating with the IAEA in April 2009 and international monitors withdrew after removing all IAEA seals and switching off surveillance cameras. (Photo by IAEA)This piecemeal approach to safeguards need not preclude the IAEA’s eventual return to traditional verification and monitoring activities in North Korea. To the contrary, such an approach would be central to the final goal of complete denuclearization. Despite its lack of a presence in North Korea since 2009, the IAEA has continued to use open sources and a variety of analytical techniques to maintain its readiness for an eventual return to the country.

Monitoring Missile Bases

Introducing restraints on North Korea’s existing nuclear weapons would be an important means of reducing the threat to the security of the United States and its allies. No prior agreements with North Korea dealt with nuclear weapons as such, only with fissile materials and missiles. Pyongyang seems especially unlikely to permit inspections or other means of intrusive transparency at nuclear missile bases, none of which it has even declared, so how can meaningful restraints be implemented and monitored?

One approach could be to confine North Korean missiles to certain declared bases and monitor the perimeters of those bases to ensure that missiles do not leave. This type of restraint would not diminish the quantitative threat to the United States, but it could address it qualitatively by affecting North Korea’s nuclear posture and the readiness of its nuclear forces.

For this type of restraint, a nodal monitoring system could prove useful. Similar to perimeter portal monitors used in other nuclear security and arms control applications but making use of advanced sensor and network technologies, such a system would monitor the movement of specified items. Nodes consisting of a variety of sensors would be placed at specific ingress and egress points. This would require inspectors to have physical access to the perimeter of such a facility but not necessarily a persistent on-site presence. In a case where on-site presence might be tolerated by North Korea, for instance, at a well-known and declared complex such as Yongbyon, additional nodes could be arrayed in order to confine specific items to an individual building.

Although this approach could make verification more technologically complex, it would also be more flexible. It may be initially more acceptable to North Korea than intrusive inspections. With time and deeper implementation of restraints, Pyongyang may allow for the progressive expansion of nodal monitoring at certain sites.

The technology base for nodal monitoring is well developed, but building a robust networked system, especially one that could be left unattended, would require additional research, development, and testing. Beyond providing for multiple types of sensors, a ready-to-deploy node should include a secure, reliable, and encrypted data relay, in situ power generation, and the ability to operate without excessive maintenance. To assuage Pyongyang’s concerns about a nodal system facilitating unsanctioned intelligence gathering and to build trust, North Korean technical experts could participate in the testing and development of these nodes, subject to export control restrictions.

New Approaches and Tools

As the above examples indicate, verifying and monitoring the various elements of North Korea’s increasingly vast nuclear weapons and missile enterprise will require new approaches. Even a modestly successful process of denuclearization will require policymakers to cope with an expanding array of North Korean facilities, materials, and processes. Obstacles are likely to emerge as verification grows more complex and Pyongyang remains reluctant to permit international access. Meanwhile, political concerns about North Korean secrecy and noncompliance are certain to persist under any agreement. To make practical progress, policymakers must avoid letting perfect verification become an enemy of sufficient verification.

One way policymakers could address these issues would be to adopt a framework of probabilistic verification. In situations where high-confidence monitoring of the few key facilities or activities of interest is unavailable or infeasible, which is manifestly the case in North Korea, negotiators could instead seek to verify compliance by monitoring a broader range of facilities and activities with lower confidence levels. As long as enough of North Korea’s total nuclear and missile complex is covered by such an agreement, Pyongyang would be unlikely to gain a meaningful advantage even if it is able to successfully evade monitoring at one single facility.11

Similarly, to support verification, negotiators could rely more heavily on open-source intelligence. An often-overlooked set of tools with growing contemporary relevance, it involves information that is not derived from classified sources and is already a major source of analytical insight into North Korean activities among civil society organizations and journalists. Although governments have traditionally favored national technical means and other proprietary tools, the use of open sources in the North Korean context could usefully augment verification and monitoring, especially in the case of a limited agreement that may be likely to emerge early in a longer negotiating process.

By their very nature, open sources are shareable, which can help build confidence in compliance among parties to an agreement. This could also allow for reciprocity, whereby North Korea, despite lacking any national remote sensing capabilities, could use commercially available satellite imagery to verify, for example, certain types of U.S. military activities covered under an agreement. Although open-source intelligence methods may fall short of national technical means, they can complement proprietary verification tools and more readily be shared with the international community, especially when some parties to an agreement, such as Beijing and Washington, are unlikely to cooperate with each other. In particular, as commercial open-source sensors broaden to include thermal, near-infrared, and other nonvisible spectrum sensors, their role in verification can grow. Several North Korean facilities of interest to negotiators, including missile test stands, the Punggye-ri nuclear test site, and heavy-military-vehicle manufacturing plants, can already be usefully monitored with commercially available sensors.

Planning Ahead

At the moment, diplomatic momentum for any negotiated agreement with North Korea remains low. The United States and North Korea have had no meaningful bilateral interactions since the fizzled 2019 Hanoi summit between Trump and Kim. A working-level meeting in Stockholm in October 2019 was terminated almost immediately by the North Korean side, just days after Pyongyang carried out the inaugural launch of the Pukguksong-3 submarine-launched ballistic missile, making clear its disinterest in diplomacy.

Moreover, weeks before North Korea locked down its borders in January 2020, citing a threat to its “national survival” from the emerging COVID-19 virus, Kim disavowed his earlier April 2018 self-imposed moratorium on long-range missile and nuclear testing in an address to the Workers’ Party of Korea plenum. With the apparent end of the diplomatic charm offensive that began with Kim’s outreach to South Korea ahead of the Pyeongchang Winter Olympic Games in early 2018, North Korea’s self-restraint has waned. Two military parades, in October 2020 and January 2021, further exhibited the fruits of Pyongyang’s accelerated nuclear force modernization.

Against this backdrop, the task of verifying and monitoring prospective agreements to restrain North Korea’s nuclear and missile capabilities presents no shortage of challenges. Innovative and even unorthodox approaches and tools can help render these challenges more manageable. With realistic expectations about what is feasible given persistent mistrust between North Korea and the outside world, the Biden administration, along with allies South Korea and Japan and other international partners, could meaningfully realize its objective of near-term threat reduction. Traditional verification remains the preferred standard, but practical progress in the near term will require novel methods for verification and monitoring in North Korea.



1. “Press Gaggle by Press Secretary Jen Psaki Aboard Air Force One en Route Philadelphia, PA,” The White House, April 30, 2021, https://www.whitehouse.gov/briefing-room/press-briefings/2021/04/30/press-gaggle-by-press-secretary-jen-psaki-aboard-air-force-one-en-route-philadelphia-pa/.

2. Howard Diamond, “U.S. Says N. Korea Site Nuclear Free; Perry Visits Pyongyang,” Arms Control Today, April 1999, https://www.armscontrol.org/act/1999-04/press-releases/us-says-n-korea-site-nuclear-free-perry-visits-pyongyang.

3. Joel Wit, “What I Learned Leading America’s 1st Nuclear Inspection in North Korea,” NPR, January 22, 2019, https://www.npr.org/2019/01/22/681174887/opinion-what-i-learned-leading-americas-1st-nuclear-inspection-in-north-korea.

4. Peter Crail, “Six-Party Talks Stall Over Sampling,” Arms Control Today, January 2009, https://www.armscontrol.org/act/2009_01-02/sixpartytalksstall.

5. Choe Sang-hun, “North Korea Claims to Conduct 2nd Nuclear Test,” The New York Times, May 24, 2009.

6. North Korean Foreign Minister Ri Yong Ho, press conference, Hanoi, February 28, 2019, https://www.youtube.com/watch?v=o-NWGHQt_rk.

7. “Pyongyang Joint Declaration of September 2018,” The National Committee on North Korea, September 19, 2018, https://www.ncnk.org/node/1633.

8. This test stand remains in place.

9. Colin Kahl, Keynote address at 2021 Carnegie International Nuclear Policy Conference, June 23, 2021, https://ceipfiles.s3.amazonaws.com/pdf/Colin+Kahl+Keynote_Transcript.pdf.

10. For summaries of each of these concepts, tools, and approaches to verification and monitoring, see New Approaches to Verifying and Monitoring North Korea’s Nuclear Arsenal, eds. Ankit Panda et al. (Washington: Carnegie Endowment for International Peace, 2021), https://carnegieendowment.org/files/Pandaetal_NorthKoreaNuclear1.pdf.

11. For a detailed discussion of probabilistic verification in the North Korean context, see Mareena Robinson Snowden, “Probabilistic Verification: A New Concept for Verifying the Denuclearization of North Korea,” Arms Control Today, September 2019, https://www.armscontrol.org/act/2019-09/features/probabilistic-verification-new-concept-verifying-denuclearization-north-korea.


Ankit Panda is the Stanton Senior Fellow in the Nuclear Policy Program at the Carnegie Endowment for International Peace (CEIP). Toby Dalton is a co-director and senior fellow in the program. With Thomas MacDonald and Megan DuBois, they are editors of New Approaches to Verifying and Monitoring North Korea’s Nuclear Arsenal (2021), on which this article is based.

North Korea’s nuclear and missile capabilities present huge challenges. Nevertheless, innovative and even unorthodox approaches and tools can help render these challenges more manageable.


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