The 2024 Presidential Race and the Nuclear Weapons Threat

Volume 16, Issue 3 
June 25, 2024

Today, nearly 80 years after the beginning of the nuclear age, the risks posed by nuclear weapons are escalating. U.S. presidential leadership may be the most important factor in whether the risk of nuclear arms racing, proliferation, and war will rise or fall in the years ahead.

As UN Secretary-General António Guterres said in a June 7 statement: “Humanity is on a knife's edge. The risk of a nuclear weapon being used has reached heights not seen since the Cold War. States are engaged in a qualitative arms race. [W]e need disarmament now. All countries need to step up, but nuclear weapons states must lead the way.”

Nuclear weapons are not just a global concern. This week the United States Conference of Mayors unanimously adopted a new resolution, titled: “The Imperative of Dialogue in a Time of Acute Nuclear Dangers.”

American voters are increasingly aware and, according to recent polling, deeply concerned about nuclear weapons dangers. A 2024 national opinion survey found that a majority of Americans believe that nuclear weapons make the world more dangerous. Overall, just one in eight Americans (13 percent) think nuclear weapons are making the world a safer place, while 63 percent think the opposite, and 14 percent say neither.

In 2024, the candidates’ approaches to these dangers deserve more scrutiny.

How exactly 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 some clues.

U.S. President Donald Trump (L), Democratic Presidential candidate former US Vice President Joe Biden and moderator, NBC News anchor, Kristen Welker (C) participate in the final presidential debate at Belmont University in Nashville, Tennessee, on October 22, 2020. (Photo by Chip Somodevilla / POOL / AFP)

The Goal: Avoiding Nuclear War

Perhaps the most consequential responsibility for a U.S. president, who has the sole authority to order the use of nuclear weapons, is to avoid events that could lead to a nuclear war.

Today, there is a heightened risk of nuclear use involving Russia and its war on Ukraine, a serious risk of a conflict with nuclear-armed China over its claims to Taiwan, and plausible scenarios involving nuclear war with North Korea, which already may have the capability to hit the United States with a nuclear-armed ballistic missile

Every U.S. president in the nuclear age has faced at least one crisis that could have led to nuclear war. Each in their own way has realized, as Ronald Reagan put it in 1984, that "a nuclear war cannot be one and must never be fought."

At a 2019 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.” Trump administration officials objected, and the statement was not adopted. Two years later, in January 2022, Biden administration officials successfully pressed the group to reaffirm the statement, and they did.

In 2017, President Trump engaged in a months-long showdown with North Korean leader Kim Jong Un that involved exchanges of harsh rhetoric and military moves and countermoves. At one point, on August 8, Trump promised Kim "fire and fury" if he conducted more ballistic missile tests. In his first address to the United Nations on Sept. 19, Trump said. "... if it is forced to defend itself or its allies, we will have no choice but to totally destroy North Korea."

In interviews afterward, it was revealed that Trump and Kim thought that nuclear war almost broke out on the Korean Peninsula in 2017. Trump told Bob Woodward in an interview for his book, Rage, that war with Pyongyang was “much closer than anyone would know.”

After Russian President Vladimir Putin launched a full-scale attack on Ukraine and issued threats of nuclear use, Biden also faced the specter of nuclear conflict. Since Russia's invasion, Biden has not issued nuclear counterthreats publicly and he has continued to back Ukraine in its struggle to repel Russia’s invasion.

The risk of nuclear use became acute in late 2022 when Putin issued another nuclear threat suggesting that Moscow was considering using a nuclear weapon on the battlefield in Ukraine to freeze Russian gains and force Kyiv and its backers into submission.

On Oct. 6, Biden reportedly said  at a fundraising event that "for the first time since the Cuban Missile Crisis, we have a direct threat of the use of a nuclear weapon if in fact things continue down the path they’ve been going.”

In an interview with CBS News’s “60 Minutes,” Biden was asked what he would tell Putin if the Russian leader were considering using nuclear weapons against Ukraine. “Don’t. Don’t. Don’t,” Biden said. “You will change the face of war unlike anything since World War II.”

Biden declined to detail how the United States would respond, saying only that the reaction would be “consequential” and would depend “on the extent of what they do.”

Biden also dispatched CIA director William Burns to privately warn the Kremlin that “there would be clear consequences for Russia" if Russia used nuclear weapons in Ukraine. U.S. officials privately pressed Chinese and Indian leaders to urge Putin to halt the nuclear threats, and they did.

In November 2022, Biden also joined leaders of the Group of 20 states meeting in Indonesia in declaring that the use of nuclear weapons and threats of their use are “inadmissible.”

The Biden and Trump Track Records on Arms Control with Russia and China

Effective U.S. leadership on arms control will be critical to avoid a destabilizing, three-way arms race after the only remaining Russian-U.S. arms control agreement, the New Strategic Arms Reduction Treaty (New START), expires in 2026.

The Trump and Biden approaches to nuclear arms control have differed on paper and in practice.

Trump's 2018 formal Nuclear Posture Review document states that “the United States will remain receptive to future arms control negotiations if conditions permit” and if such accords “advance U.S. and allied security, are verifiable, and enforceable.” It adds that the administration “will continue to pursue the political and security conditions that could enable further nuclear reductions.”

Biden's 2022 Nuclear Posture Review report states that the United States “will seek opportunities to pursue practical steps to advance the goals of greater transparency and predictability, enhanced stability, reduced reliance on nuclear weapons and, ultimately, a world without nuclear weapons.”

As the first expiration deadline for New START approached on Feb. 5, 2021, Trump's team refused to agree to a simple 5-year extension of the pact. Instead, they said that the United States would contemplate only a short-term extension of the treaty – and only if Russia agreed to a framework for a new trilateral treaty that verifiably covers all nuclear warheads, includes those of China in the future, and makes changes to the painstakingly-negotiated New START verification regime

At one point, Trump's arms control envoy threatened that the United States could spend Russia and China “into oblivion” in a new nuclear arms race if they did not agree to the U.S. proposals.

This left the incoming Biden administration only days after inauguration day to reach a deal with the Kremlin to extend the pact by five years, and it did in early 2021. After their summit in Geneva that year, Biden and Putin agreed to resume "strategic stability" talks, but these were suspended following Russia's February 2022 invasion of Ukraine.

In June 2023, the Biden administration proposed talks with Russia “without preconditions” on a new, post-2026 “nuclear arms control framework.” In his September 2023 speech to the UN, Biden reiterated that “no matter what else is happening in the world, the United States is ready to pursue critical arms control measures.”

In January 2024, however, Russia formally rejected the U.S. offer to re-open the nuclear arms control dialogue because, it said, the United States was seeking the strategic defeat of Russia through its support of Ukraine.

Russia and the United States have pledged to stay within the limits set by New START (1,550 deployed strategic nuclear warheads) as long as it is in force and as long as the other side does the same. But without a new understanding to restrain their strategic arsenals after the treaty expires, the two countries could double the size of their deployed arsenals by uploading additional warheads on existing missiles.

Many arms control experts believe that as long as there is war in Ukraine, the best outcome is a simple deal committing both sides to stay below the current limit of 1,550 deployed strategic warheads until a longer-term Russian-U.S. nuclear arms control framework agreement can be concluded.

Biden also has pursued nuclear risk reduction talks with China, which continues a major nuclear buildup begun during the Trump era. Independent experts estimate China currently has some 500 nuclear weapons in total, including 310 on long-range, strategic systems. In November, senior Chinese and U.S. officials held the first nuclear risk reduction talks in years. However, China recently declined to resume talks on nuclear risk reduction.

On June 7, a senior White House official said: “... we do not need to increase our nuclear forces to match or outnumber the combined total of our competitors to successfully deter them.” But he added: “Absent a change in the trajectory of adversary arsenals, we may reach a point in the coming years where an increase from currently deployed numbers is required.”

Since leaving office, Trump has not spoken about his plan to reduce nuclear dangers (nor has he been asked to), but his former national security advisor, Robert O'Brien, wrote in a recent Foreign Affairs article: "The United States has to maintain technical and numerical superiority to the combined Chinese and Russian nuclear stockpiles."

The United States has some 3,700 warheads in its active arsenal. This includes 1,670 thermonuclear warheads deployed on 660 powerful, long-range missiles on land and at sea, and that can be delivered on strategic bombers, plus another 100 "tactical" nuclear bombs on shorter-range aircraft according to independent estimates. Russia's deployed nuclear force is roughly equivalent in size. China is currently estimated to have some 500 nuclear weapons and 310 long-range, nuclear-armed ballistic missiles.

The use of just a fraction of these arsenals would lead to mass destruction on an unprecedented, global scale.

More Nuclear Weapons, More Spending?

For some 15 years, the United States has been pursuing an across-the-board effort to modernize, upgrade, and maintain its entire nuclear enterprise, including plans for:

  • a new land-based intercontinental-ballistic missile (the Sentinel ICBM); a new fleet of strategic subs (Columbia-class); a new fleet of strategic bombers (the B-21)
  • a new air-launched cruise missile (LRSO); a new sea-based cruise missile (SLCM-N)
  • refurbishment of all nuclear warhead types, a new-design warhead (the W-93), and two new plutonium pit production facilities that can produce 80 units per year.

Costs have risen under the Trump administration and the Biden administration, which has led to calls for a re-evaluation of the effort.

In 2017, the Congressional Budget Office (CBO) estimated that the plans Trump inherited from Obama to maintain and upgrade the arsenal over the next 30 years would cost $1.2 trillion in current dollars. In 2023, the cost estimate had risen to more than $1.5 trillion over the next 30 years.

U.S. Nuclear Weapons Modernization Costs At-A-Glance
CBO total cost est. Fiscal 2023-2032$756 billion
Fiscal 2025 Biden Request (DoD and NNSA activities)$69 billion (up 22%)

According to CBO, the Department of Defense’s (DoD’s) and the Department of Energy’s (DOE’s) current plans call for spending more than $756 billion over the 2023–2032 period, or an average of just over $75 billion a year.

Nuclear weapons-related costs will likely grow even more. Some of these programs are more expensive than others, riskier, and more vulnerable to delay or cancellation.

For example, the Air Force announced in January that the new Sentinel ICBM would cost 37 percent more than expected and take about two years longer than planned to build and deploy. The cost hike puts the Sentinel program in a “critical” breach of the Nunn-McCurdy Act, a law designed to prevent major cost overruns. The delay will increase the cost of extending the life of the 400 Minuteman III ICBMs now deployed in Colorado, Montana, Nebraska, N. Dakota, and Wyoming.

Sentinel Missile Program Costs At-A-Glance
Original per unit price for the Sentinel$118 million
Current per unit price for the Sentinel$162 million
Estimated 10-year program cost, incl. 450 new launch facilities$120 billion
Estimated 50-year life-cycle cost$320 billion
Estimated cost for new W87-1 warhead for the Sentinel$15 billion

Trump said on Feb. 12, 2018, that the United States is “creating a brand-new nuclear force. [W]e’re gonna be so far ahead of everybody else in nuclear like you’ve never seen before.”

During the Trump years, nuclear modernization costs grew, and his administration proposed "supplements" to the nuclear force to give the president more nuclear options.

As a candidate, Joe Biden pledged "to maintain a strong, credible deterrent while reducing our reliance and excessive expenditure on nuclear weapons." Under his leadership, however, costs have also grown. His fiscal year 2025 budget request calls for $69 billion for nuclear weapons operations, sustainment, and modernization, which is 22 percent higher than last year.

Biden has supported the Obama-era "program of record" to replace and upgrade existing nuclear weapons systems and has opposed a Trump-era proposal for a new nuclear-armed, sea-launched cruise missile. However, Congress has mandated that a program must be established for the weapon.

Additional cost increases could crowd out funding for other critical, non-nuclear defense programs. Further delays with the Sentinel missile and Columbia-class strategic sub could lead to changes to the existing nuclear force structure. Nevertheless, several Republican members of Congress are advocating for an even more ambitious and costly nuclear modernization and expansion effort involving:

  • significantly increasing the number of deployed strategic nuclear warheads (now numbering 1,439) by uploading more warheads on ICBMs
  • increasing the number of ICBM silos from 400 to 450
  • putting a large portion of the strategic bomber force back on continuous nuclear alert status
  • developing and building a new SLCM-N and associated warhead
  • considering building an additional strategic submarine

How a second Biden administration or a second Trump administration might pursue these ideas and manage the cost and security challenges is not clear.

Nuclear Testing

The 1996 Comprehensive Nuclear Test Ban Treaty (CTBT), which the United States has signed but not ratified, effectively brought an end to the era of nuclear explosive testing.

However, concerns about a possible nuclear testing revival are on the rise as China, Russia, and the United States modernize their arsenals and continue to engage in nuclear activities at their former nuclear testing sites.

The vast majority of the 2,056 nuclear test explosions conducted between 1945 and 2017 (including 1,030 by the United States) were to proof-test new warhead designs. Only North Korea has conducted nuclear tests in this century.

The Trump administration declared in 2018 that the United States did not intend to ratify the CTBT and it shortened the time necessary to resume nuclear testing from 24-36 months to 6-10 months.

In May 2020, senior Trump officials reportedly discussed the idea of the United States resuming nuclear testing in order to intimidate China and Russia into accepting U.S. terms at the negotiating table. The U.S. House of Representatives responded by voting to bar funding for any such action.

During the 2020 campaign, Biden called the idea of resuming nuclear testing “as reckless as it is dangerous,” and said, “We have not tested a device since 1992; we don’t need to do so now.”

The Biden administration has reaffirmed U.S. support for the treaty but has not taken steps to secure Senate advice and consent for ratification. Senior Biden officials have said there is no technical or military need to resume nuclear testing due to the success of the U.S. stockpile stewardship program. The head of the National Nuclear Security Administration has proposed technical talks with Beijing and Moscow on confidence-building arrangements at the former Chinese, Russian, and U.S. test sites to ensure that their subcritical nuclear experiments are not full-scale tests, which would violate the CTBT.

In his recent Foreign Affairs article, O’Brien, one of Trump’s former national security advisors, suggested that the United States should resume testing. "Washington must test new nuclear weapons for reliability and safety in the real world for the first time since 1992—not just by using computer models," he wrote.

Putin has pledged to resume nuclear testing if the United States does, and it is possible that China, which has conducted 45 nuclear tests compared to 1,030 by the United States, also would respond in kind.

Preventing a Nuclear-Armed Iran

U.S. presidents have been seeking to contain Iran's sensitive nuclear activities since the 1990s.

In 2018, the Trump administration withdrew unilaterally from the 2015 Joint Comprehensive Plan of Action and imposed tougher U.S. sanctions to try to pressure Tehran into negotiating a new and "better" deal..Since then, Iranian leaders have increased their capabilities to produce weapons-grade uranium significantly and curtailed cooperation with the International Atomic Energy Agency. As a result, Iran would need only weeks to amass enough highly enriched uranium for one bomb, as opposed to more than a year under the 2015 nuclear deal)

Biden pledged to restore mutual compliance with the 2015 deal but so far has not and few experts believe the agreement can be revived at this point. The effort was stymied by Iranian demands on matters outside the nuclear file and tensions over the war in Gaza.

Iranian and U.S. officials continue backchannel talks on how to deescalate tensions, but Iran has threatened to pull out of the nuclear Nonproliferation Treaty if the United States or other UN Security Council members snap back international sanctions against Iran as most former Trump advisers have proposed.

Avoiding a more severe crisis over Iran’s nuclear program will require more sophisticated U.S. diplomacy.

Managing the North Korean Threat

For decades, U.S. presidents have sought to use a combination of diplomacy and sanctions to curb North Korea's capability to produce bomb-grade nuclear material, nuclear weapons, and sophisticated missiles that can deliver them. At some points, these efforts have been successful. At other stages, not so much. Today, North Korea has a relatively small but deadly nuclear arsenal and a variety of missiles that can be used to deliver them, including long-range missiles that can reach the United States.

Strongman leader Kim has ramped up North Korean nuclear and missile development and stiff-armed overtures for talks with the Trump administration and the Biden administration ever since the disastrous 2019 summit in Hanoi, when Trump flatly rejected Kim’s offer to dismantle North Korea's Yongbyon nuclear complex in return for limited sanctions relief, then walked out of the meeting.

Renewed talks to try to curb North Korea’s nuclear weapons and ballistic program and lower tensions will require a recalibration of the U.S. approach and coordinated action by U.S. allies and very likely China.

Bottom Line

Given what is at stake, the voting public deserves to know more about how every presidential candidate plans to address the nuclear danger.