"[Arms Control Today] has become indispensable! I think it is the combination of the critical period we are in and the quality of the product. I found myself reading the May issue from cover to cover."

– Frank von Hippel
Co-Director of Program on Science and Global Security, Princeton University
June 1, 2018
Daryl Kimball

Nuclear Weapons Policy Experts Praise Biden for Transparency on Nuclear Arsenal


Statement by Daryl G. Kimball, Executive Director

For Immediate Release: October 6, 2021

Media Contacts: Daryl G. Kimball, executive director, (202) 463-8270 ext.107; Shannon Bugos, research associate, (202) 463-8270 ext. 113

The Biden administration’s decision to declassify updated information on the number of nuclear warheads in the U.S. nuclear weapons arsenal is a welcome step that reverses an unwise decision by the Trump administration to classify this information. It also puts pressure on other nuclear armed states that maintain excessive secrecy about their arsenals, and highlights the need for further steps to reduce the number, role, and risk of nuclear weapons in the United States and world’s other eight nuclear-armed states.

The October 5 declassification announcement indicates that the total number of “active” and “inactive” warheads is 3,750 as of September 2020. The stockpile figures do not include retired warheads and those awaiting dismantlement. The updated stockpile number is only 72 warheads fewer than the figure announced in September 2017, after which the Trump administration decided as a matter of policy not to provide any further updates on the size of the U.S. stockpile.

Interestingly, the detailed figures released yesterday show, Donald Trump as the first post-Cold War  that for the first time in 25 years, the United States increased the size of the nuclear arsenal between the years 2018 and 2019. As our colleagues at the Federation of Scientists suggest, this may be due to the deployment of the a new, low-yield warhead on the D-5 sub-based strategic ballistic missile by the Trump administration.

In a democratic society, it is essential that the public and our elected leaders have the information necessary to engage in a fact-based discussion of key issues affecting national and international security—nuclear weapons being among the most consequential.

By being more transparent about the U.S. nuclear weapons stockpile size, the United States is on much firmer ground to put pressure on other nuclear-armed states, particularly Russia and China to be more responsible nuclear possessors by providing basic information on the number and types of nuclear weapons in their arsenals. This is essential to understanding whether and how they world’s nuclear-armed states are—or are not—meeting their obligations under the nuclear Nonproliferation Treaty and elsewhere to "pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament ….”

Agreement on enhanced nuclear stockpile transparency is also necessary if there is to be further progress on arms control and disarmament measures between the United States and Russia beyond the 2010 New Strategic Arms Reduction Treaty (New START) and with China in the future.

The updated U.S. nuclear stockpile figures do, however, underscore several troubling realities:

  • progress toward serious nuclear weapons stockpile reductions have stalled in recent years, and some states, particularly China and Russia, appear to be increasing the size and/or diversity of their arsenals.
  • an arsenal of 3,750 nuclear warheads, including approximately 1,389 strategic deployed warheads on 665 land-based and sea-based missiles and bombers accountable under New START, is more than enough to deliver a devastating nuclear blow to any nuclear-armed adversary. It would take just a few hundred U.S. nuclear weapons to destroy Russian and Chinese military capacity, kill hundreds of millions of innocent people, and produce a planetary climate catastrophe. And according to previous Pentagon assessments, the United States could further reduce its deployed strategic arsenal even further and still deter a nuclear weapons attack by any nuclear-armed adversary against the United States or our treaty allies. 

The Biden administration has pledged to “take steps to reduce the role of nuclear weapons in our national security strategy” and to seek to “head off costly arms races and re-establish our credibility as a leader in arms control.”

As the administration continue to work on its Nuclear Posture Review, we hope and expect it will take further tangible steps to provide the leadership necessary to reduce the role and number of nuclear weapons worldwide.


The Biden administration’s decision to declassify information on the number of U.S. nuclear warheads is a welcome step that reverses an unwise decision by the Trump administration.

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Biden’s NPR Must Reduce the Role of Nuclear Weapons

October 2021
By Daryl G. Kimball

Most successful U.S. presidents have actively led efforts to advance arms control agreements and reduce the risk of nuclear war. Although much has been achieved over the years, there are still 14,000 nuclear weapons and nine nuclear-armed states; progress on disarmament has stalled; and tensions between the United States and its main nuclear adversaries—Russia and China—are rising.

A deactivated Minuteman II missile in its silo. (Photo credit: U.S. National Park Service)President Joe Biden clearly recognizes the problem and the value of diplomacy and nuclear restraint in solving it. His Interim National Security Strategic Guidance states that his administration will seek to “re-establish [its] credibility as a leader in arms control” and “take steps to reduce the role of nuclear weapons in [U.S.] national security strategy.” In February, Biden and Russian President Vladimir Putin agreed to extend the New Strategic Arms Reduction Treaty (New START) and negotiate further nuclear limits.

But it remains to be seen whether Biden’s recently launched Nuclear Posture Review (NPR) will lead to meaningful adjustments in the dangerous Cold War-era nuclear policies and costly nuclear modernization programs he inherited. Earlier this year, Biden blew the chance to meaningfully scale back his predecessor’s bloated $44 billion annual nuclear budget.

Going forward, Biden needs to play a more direct role in the NPR to ensure it reflects his priorities and does not reinforce the dangerous overreliance on nuclear weapons and exacerbate global nuclear competition. As I and other experts recommended in a recent letter to the White House, the president should make important changes in several key areas.

First, the NPR should include a declaratory policy that substantially narrows the role of nuclear weapons, consistent with Biden’s stated views. In 2020, he wrote, “I believe that the sole purpose of the U.S. nuclear arsenal should be deterring—and, if necessary, retaliating against—a nuclear attack. As president, I will work to put that belief into practice.”

A “sole purpose” policy that rules out the use of nuclear weapons in a preemptive strike or in response to a nonnuclear attack on the United States or its allies would increase strategic stability, reduce the risk of nuclear war, and help operationalize the principle that Biden and Putin agreed to in July that “a nuclear war cannot be won and must never be fought.” The more options there are to use nuclear weapons, the more likely it is that they will be used.

Second, the NPR should revise outdated targeting requirements that are used to determine how many nuclear weapons are “enough.” Although Russia is modernizing its arsenal and China is rapidly increasing its smaller strategic retaliatory force, including systems to evade U.S. missile defenses, the current U.S. nuclear arsenal vastly exceeds what is and will be necessary to deter a nuclear attack.

President Barack Obama announced in 2013 that the United States could safely reduce its deployed strategic nuclear weapons by one-third below New START levels, to approximately 1,000 deployed strategic weapons, regardless of what Russia did. The case for such a reduction still holds.

Contrary to the Cold War logic of U.S. Strategic Command, having more bombs and more delivery options does not translate into more effective deterrence. It can fuel arms races and squander funds needed to address higher priority security needs. The sobering reality is that it would take just a few hundred U.S. strategic nuclear weapons to destroy Russian and Chinese military capacity, kill hundreds of millions of innocent people, and produce a planetary climate catastrophe.

By signaling that the United States seeks a smaller, more appropriately sized nuclear force, Biden could help lower tensions, put a spotlight on other nuclear-armed states that are expanding their arsenals, and more credibly claim the United States is fulfilling its obligations under the nuclear Nonproliferation Treaty.

Third, Biden’s NPR should examine options for scaling back the size and scope of the U.S. nuclear modernization plan and put into practice the “no new nuclear weapons” policy he said he would support during his presidential campaign. He should reverse the decisions made by the Trump administration to field a new lower-yield W76-2 warhead variant and to develop a new nuclear sea-launched cruise missile. These weapons invite miscalculation in a crisis by lowering the threshold for nuclear use. New warhead projects, such as the W93 for U.S. and UK submarine-based missiles, are also unnecessary and costly and should be shelved.

In his inaugural address to the United Nations, Biden said, “[W]e stand…at an inflection point in history.” He is right. The actions that world leaders take in the next decade are critical to whether we address massive global threats and challenges, including the existential threat of nuclear war. Biden must do his part by implementing policies that reduce the salience of nuclear weapons and head off a new arms race.

Most successful U.S. presidents have actively led efforts to advance arms control agreements and reduce the risk of nuclear war. 

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.


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