January/February 2024  
By Daryl G. Kimball

As the new year begins, the existential risks posed by nuclear weapons continue to grow. A crucial factor in whether one or more of today’s nuclear challenges erupt into full-scale crisis, unravel the nonproliferation system, or worse will be the outcome of the U.S. presidential election.

How the winner of the 2024 race will handle the evolving array of nuclear weapons-related challenges is difficult to forecast, but the records and policies of the leading contenders, President Joe Biden and former President Donald Trump, offer clues.

A major responsibility for any commander in chief is to avoid events that can lead to a nuclear war with Russia over its war on Ukraine and with China over its claims to Taiwan. One indicator of Trump’s more confrontational approach came in 2019 when, at a meeting of senior officials from the five nuclear-armed states recognized under the nuclear Nonproliferation Treaty (NPT), China proposed a joint statement reiterating that “a nuclear war cannot be won and must never be fought.” Two years later, Biden administration officials successfully pressed the group to reaffirm this Reagan-Gorbachev maxim, first enunciated in 1985.

Since then, Russian President Vladimir Putin’s full-scale attack on Ukraine and threats of nuclear use have raised the specter of nuclear conflict. To his credit, Biden has not issued nuclear counterthreats and has backed Ukraine in its struggle to repel Russia’s invasion. In 2022, Biden also joined leaders of the Group of 20 states in declaring that the use of nuclear weapons and threats of their use are “inadmissible.”

Well before Putin’s nuclear rhetoric turned ominous, Trump engaged in an alarming exchange of taunts with North Korean leader Kim Jong Un in 2017. His threats of unleashing “fire and fury” against Pyongyang fueled tensions on the Korean peninsula and provide another clue how he might behave in a crisis with China, North Korea, or Russia in a second term.

Effective U.S. leadership on arms control will be critical to avoid a destabilizing, three-way arms race after the New Strategic Arms Reduction Treaty expires in 2026. As the treaty’s first expiration deadline of February 5, 2021, was approaching, Trump refused to agree to simple extension of the pact, focusing instead on a failed effort to cajole China into joining Russian-U.S. arms talks. This left the incoming Biden administration only days to reach a deal with the Kremlin to extend the pact by five years, and it did.

In June 2023, the Biden administration proposed talks with Russia “without preconditions” on a new, post-2026 “nuclear arms control framework.” As long as there is war in Ukraine, the best outcome likely is a simple deal committing both sides to stay below the current limit of 1,550 deployed strategic warheads until a longer-term framework is concluded. Biden also has pursued nuclear risk reduction talks with China, which continues its nuclear buildup begun during the Trump era. In November, senior Chinese and U.S. officials held the first such talks in years.

Meanwhile, Iranian leaders continue increasing their capabilities to produce weapons-grade uranium in response to Trump's 2018 decision to withdraw unilaterally from the 2015 Joint Comprehensive Plan of Action and impose tougher U.S. sanctions to pressure Tehran into negotiating a new deal. They now are threatening to pull out of the NPT if the United States or other UN Security Council members snap back international sanctions against Iran.

Biden’s efforts to restore mutual compliance with the 2015 deal have been stymied by Iranian demands on matters outside the nuclear file and tensions over the war in Gaza. Avoiding a more severe crisis over Iran’s nuclear program will require more sophisticated U.S. diplomacy.

Kim has ramped up North Korean nuclear and missile development and stiff-armed overtures for talks with Washington ever since the disastrous 2019 Hanoi summit, when Trump flatly rejected Kim’s offer to dismantle the Yongbyon nuclear complex in return for limited sanctions relief, then walked out of the meeting. Renewed talks on curbing North Korea’s weapons program will require a recalibration of the U.S. approach.

Concerns about a possible nuclear testing revival also are rising. The Trump administration did not help when it declared in 2018 that the United States did not intend to ratify the Comprehensive Test Ban Treaty and in 2020 when senior Trump officials discussed resuming explosive testing to intimidate China and Russia. Biden, on the other hand, has reaffirmed U.S. support for the treaty; and his team proposed technical talks on confidence-building arrangements at the former Chinese, Russian, and U.S. test sites.

Most Americans do not vote based on candidates’ positions on nuclear weapons, but they are aware and deeply concerned about nuclear dangers. A 2023 national opinion survey found that large majorities believe that nuclear weapons are the most likely existential threat to the human race.

In 2024, the candidates’ approaches to these dangers deserve more scrutiny than usual. Presidential leadership may be the most important factor that determines whether the risk of nuclear arms racing, proliferation, and war will rise or fall in the years ahead.

January/February 2024
By Shizuka Kuramitsu

The United States is making progress in developing a safer low-enriched uranium (LEU) fuel for use in Navy ships, but the project is very costly, and success is not assured, according to a report by the National Nuclear Security Administration (NNSA).

The United States now relies on highly enriched uranium to provide safe, long-lived, and reliable naval propulsion fuel. But nonproliferation experts have been urging a switch to LEU, which is more difficult to convert for use in nuclear weapons.

In a message accompanying the report, NNSA Administrator Jill Hruby said she was “pleased with the progress…made in this technically challenging effort…[because in] fiscal 2021, we reached a critical milestone” with experiments that will produce the first information evaluating novel fuel-fabrication techniques, as well as fuel performance characteristics.

Nevertheless, the report struck a downbeat tone, concluding that “these initial activities are the first steps on a long, costly path to fuel development and success is not assured.”

It predicted a reactor fuel system design effort lasting 20 to 25 years that would cost more than $1 billion and detract from higher-priority nonproliferation and naval propulsion research and development activities.

“Even if successful, the propulsion system would be less capable, only [be] applicable to aircraft carriers and require several billion dollars, in addition to fuel development costs, to deploy the supporting engineering, manufacturing and testing infrastructure,” the report said.

It added that “the analysis showed that the use of LEU would negatively impact reactor endurance, reactor size, ship costs and operational effectiveness.”But the nonproliferation expert who obtained and publicized the report, which was sent to Congress in 2022 and kept secret until now by the government, argued that the expense for the LEU project should not be questioned. “The program’s price tag is a tiny fraction of the cost of the nuclear Navy or a nuclear terrorist attack,” Alan J. Kuperman, an associate professor at the LBJ School of Public Affairs at the University of Texas at Austin and coordinator of the university’s Nuclear Proliferation Prevention Project, told Reuters.

“These documents clarify three things for the first time: the program is vital to preventing the spread of nuclear weapons, is making rapid progress, and will be implemented only if it can preserve the performance of U.S. Navy vessels,” Kuperman said.

The NNSA has been researching LEU fuel use in Navy systems since 2018 with $50 million appropriated by Congress, but the program is now in doubt after a House subcommittee cut the funding, Reuters reported.

The nuclear fuel issue has drawn increased attention since 2021, when the United States and the United Kingdom raised proliferation concerns by agreeing to sell nuclear-powered submarines to Australia, which would become the first non-nuclear-weapon state to field a ship with an HEU-powered reactor.

January/February 2024
By Kelsey Davenport

The tenuous relationship between North and South Korea deteriorated further after Seoul announced its intention to suspend part of a joint military agreement in response to Pyongyang’s illegal launch of a satellite in November. North Korea responded by terminating its participation entirely. It later announced that unification with South Korea is no longer a viable policy goal.

South Korea announced on Nov. 22 that it will no longer abide by a no-fly zone established over the border area between the two Koreas in the Comprehensive Military Agreement. That agreement, concluded in September 2018 between South Korean President Moon Jae-in and North Korean leader Kim Jong Un, also contains restrictions on guard posts and live-fire exercises near the Demilitarized Zone between the two countries.

The move by South Korea to rescind the no-fly zone component of the agreement in response to the satellite launch does not come as a surprise. South Korean Defense Minister Shin Won-sik repeatedly has raised concerns about the agreement limiting South Korea’s ability to conduct surveillance and threatened to withdraw if North Korea launched a satellite.

Later on Nov. 22, North Korea’s Central Military Commission responded to the South Korean announcement, saying that, “from now on [North Korea] will never be bound” by the 2018 agreement. The commission said that North Korea will “immediately restore all military measures” that were halted by the agreement.

The commission blamed the collapse of the agreement and heightened tensions on South Korea, saying Seoul is creating the “most dangerous situation” and will be “wholly accountable” if conflict breaks out between the two countries.

Since Nov. 22, the two sides have redeployed additional soldiers along the demarcation line and taken steps to restore guard posts that were not in use under the agreement.

Although not directly referencing the agreement, Moon appeared to criticize the current South Korean government for revoking the agreement and its hard-line approach. In a Dec. 10 post on Facebook, Moon said that “abandoning agreements” and dialogue has “only hastened the development of North Korea’s nuclear weapons program.”

In addition to withdrawing from the miltiary agreement, Kim suggested that unification of the Korean peninsula is “impossible,” departing from a long-standing policy goal of uniting the two countries. In remarks on Dec. 31, he said that “reunification can never be achieved,” given South Korea’s goal of absorbing North Korea into its democracy, and that the two countries are no longer “homogenous.”

Kim Yung-ho, the South Korean minister of unification, disputed the claim that unification is impossible. In a Jan. 1 speech, he said that Seoul will work to establish a “master plan” for unification and warned that Kim Jong Un is trying to “suppress” South Korea.

Meanwhile, Kim Jong Un announced further plans to accelerate the production of nuclear warheads and launch an additional three surveillance satellites in 2024. Satellite imagery suggests that North Korea started operating a nuclear reactor in late 2023 that would provide additional fissile material for nuclear weapons.

Rafael Mariano Grossi, director-general of the International Atomic Energy Agency, said on Dec. 21 that the agency observed signs consistent with commissioning what may be a light-water reactor at the Yongbyong nuclear complex.

North Korea justified its military actions and nuclear expansion as a necessary response to the United States.

During a UN Security Council meeting on Nov. 27, Kim Song, North Korea’s ambassador to the United Nations, said that it is North Korea’s “legitimate right…to develop, test, manufacture, and possess weapons systems equivalent to those that the United States already possess.”

The Security Council meeting was convened to discuss North Korea’s Nov. 21 satellite launch. Pyongyang is prohibited from launching satellites under council resolutions because the rockets utilize technologies common in ballistic missiles.

Kim said that the sanctions are “illegal and unlawful” and it is necessary for North Korea to pursue satellites to “get a clear picture of the dire military moves” of the United States.

The Security Council did not take any formal action to respond to North Korea’s activities due to continued resistance from Russia and China.

U.S. Ambassador Linda Thomas-Greenfield asked the council “how many more times” it must gather in response to illegal North Korean activities before China and Russia “join us in demanding [that North Korea] abandon its weapons of mass destruction and ballistic missile programs.”

During the meeting, Russia denied accusations that it provided North Korea with any technical military assistance.

Anna Evstigneeva, Russia’s deputy permanent representative to the UN, called the allegations “groundless” during the council meeting and said that attempts to “vilify” Russia reflect a desire to “divert” the council’s attention from “the United States’ ambitions to strangle Pyongyang at any cost.”

She said that Russia “does not support steps by either side that run counter to the objectives of establishing long-term peace in the region…[but that it] does not come as a surprise” that North Korea would take steps in the “interests of self-defense.”

Thomas-Greenfield disputed the idea that North Korea is reacting to U.S. military activities. She said Pyongyang is “unabashedly trying to advance its nuclear weapons delivery systems by testing ballistic missile technology” and warned that the “reckless, unlawful behavior” is a threat. She reiterated the Biden administration’s “call for dialogue on any topic” with North Korea.

As the United States urges dialogue with North Korea, it continues to take steps to strengthen its alliance with South Korea. The two countries met on Dec. 15 for a second meeting of the Nuclear Consultative Group, which was announced when South Korean President Yoon Suk Yeol met with U.S. President Joe Biden in April. (See ACT, May 2023.)

In a joint statement following the Dec. 15 meeting, the United States and South Korea reiterated that “any nuclear attack by North Korea against the United States or its allies is unacceptable and will result in the end of the Kim regime.”

The Dec. 16 statement noted that U.S. and South Korean officials acknowledged that “nuclear deterrence cooperation deepened” through the Nuclear Consultative Group process. It said that the United States and South Korea “reviewed the enhanced visibility of strategic assets to bolster extended deterrence” and discussed “future plans to demonstrate a strengthening of deterrence.”

In a Dec. 17 statement published in the state-run Korean Central News Agency, a spokesperson from the North Korean Defense Ministry described the work of the Nuclear Consultative Group as “an open declaration on nuclear confrontation.”

The spokesperson accused South Korea and the United States of “maximizing the tension in and around the Korean peninsula with hostile and provocative acts” against North Korea and said the move “pressurizes our armed forces to opt for more offensive countermeasure[s].”

The following day, North Korea tested what appears to be a solid-fueled intercontinental ballistic missile (ICBM) on a lofted trajectory from near Pyongyang. North Korea last tested an ICBM in July.

January/February 2024
By Shizuka Kuramitsu

States-parties to the Treaty on the Prohibition of Nuclear Weapons (TPNW) have begun challenging the long-standing deterrence rationale for nuclear weapons in an effort to inject new momentum into their campaign to rid the world of these armaments.

At their second annual TPNW meeting held Nov. 27 to Dec. 1 in New York, they approved a political outcome document that unveiled the new strategy, declaring that the states-parties “will not stand by as spectators to increasing nuclear risks and the dangerous perpetuation of nuclear deterrence.”

At the suggestion of the Austrian delegation, the states-parties decided to establish a “consultative process on security concerns of TPNW states” that aims to reframe the debate over nuclear disarmament as a necessary instrument to ensure human security and national security.

“This shift at the TPNW conference indicated in Austria’s working paper is important. There are deep flaws in the assumptions that underline the current nuclear paradigm, and deterrence, although [it] works most of the time, is inherently flawed and will fail over the long run,” Ward Hayes Wilson, executive director of RealistRevolt, told Arms Control Today.

Amid a deteriorating international security environment due to the Russian war in Ukraine and other factors, nuclear-armed states recently have reaffirmed the need to possess nuclear weapons on the grounds that such armaments deter adversaries. This nuclear deterrence doctrine has been at the core of NATO’s mutual security guarantee and collective defense since the alliance was created in 1949.

At the meeting, Germany, a TPNW observer state, stressed that, “confronted with an openly aggressive Russia, the importance of nuclear deterrence has increased for many states.”

“Germany, as a NATO member, is fully committed to NATO’s nuclear deterrence, the purpose of which is to preserve peace, deter aggression, and prevent nuclear coercion,” the head of the German delegation said.

Similarly, during a meeting of the Group of Seven industrialized countries in Hiroshima in May, world leaders reaffirmed their view that “our security policies are based on the understanding that nuclear weapons, for as long as they exist, should serve defensive purposes, deter aggression and prevent war and coercion.”

But in their political document, the TPNW states-parties countered that “[t]he renewed advocacy, [and] insistence on and attempts to justify nuclear deterrence as a legitimate security doctrine [give] false credence to the value of nuclear weapons for national security and dangerously [increase] the risk of horizontal and vertical nuclear proliferation.”

In addition, nuclear threats “only serve to undermine the disarmament and non-proliferation regime and international peace and security,” the declaration stated.

The states-parties named Austria as coordinator for the new consultative process and called for a report to be submitted at the next TPNW meeting with a set of arguments and recommendations.

The process is expected “to better promote and articulate the legitimate security concerns, [and] threat and risk perceptions enshrined in the treaty that result from the existence of nuclear weapons and the concept of nuclear deterrence,” the parties decided.

Further, states-parties in partnership with scientists and civil society decided “to challenge the security paradigm based on nuclear deterrence by highlighting and promoting new scientific evidence about the humanitarian consequences and risks of nuclear weapons and juxtaposing those with risks and assumptions that are inherent to nuclear deterrence.”

Reflecting this move to delegitimize nuclear weapons, Juan Ramón de la Fuente, the Mexican ambassador who served as the TPNW meeting president, told a press conference on Dec. 1 that “there is an incompatibility between nuclear weapons and international security. That is why we are more convinced now than before [that] the only way to really move towards [a] more secure world for all of us is with the prohibition of nuclear weapons.”

At Mexico’s initiative, the meeting reinforced the new strategy by elevating debate on the humanitarian impact of nuclear weapons use and by including scientists from the newly established TPNW scientific advisory group, a speaker from the International Committee of Red Cross, and representatives of nongovernmental organizations and affected communities, including Australia, Kiribati, and Japan, to share their perspectives and findings.

“This was extremely important because it was the first time that we were addressing at this level [of an official UN conference] the catastrophic humanitarian consequences of nuclear detonation,” de la Fuente said.

Setsuko Thurlow, an atomic bomb survivor from Hiroshima, told the press conference that “[n]ow with the humanitarian initiative as a guide, we were able to look at the [nuclear weapons] issue as a human issue, to put human being[s] right in front and a center of discussion.”

Some 59 states-parties, 35 observer states, and 122 nongovernmental organizations, participated in the weeklong TPNW meeting, which elected Akan Rakhmetullin, Kazakhstan’s UN ambassador, as president of the next meeting, to be held in March 2025.