Good afternoon, everyone. It is a pleasure to be here this afternoon with my colleagues Under Secretary Jenkins and Under Secretary Kahl at the tenth Nuclear Nonproliferation Treaty Review Conference. Although this conference has been delayed, our work to meet our obligations under the NPT has not stopped. As President Biden has affirmed, the U.S. is committed to strengthening the Treaty as the cornerstone of the international nuclear nonproliferation and disarmament regime.

At the National Nuclear Security Administration (NNSA), we design, produce, and maintain a safe and secure U.S. nuclear weapons stockpile to serve as an effective deterrent for ourselves and our allies. We also support the broad objective of nuclear deterrence by advancing nuclear security, nonproliferation, and arms control using our technical expertise and knowledge, and by working with our partners in the U.S. government, foreign counterparts, and international organizations. A safe, secure, transparent nuclear deterrent combined with arms control creates stability and helps set the conditions needed to consider disarmament.

Strategic Deterrence and the Global Environment

While our effort to maintain global nuclear stability is an enduring mission, our approach to responsible stockpile stewardship and nuclear nonproliferation are informed by current global conditions.

This is a critical moment for the nonproliferation regime.

Russia’s further invasion of Ukraine has raised radiological health and safety concerns through its reckless military actions at the Chernobyl and Zaporizhzhia nuclear sites and has unraveled important nonproliferation norms.

North Korea’s continued expansion of its nuclear weapons and delivery capabilities and the uncertainty of negotiations with Iran over a return to the Joint Comprehensive Plan of Action pose proliferation risks and undermine both regional and global security.

At the same time, we see the opportunity for increased use of nuclear power to combat climate change. An increased use of nuclear energy is accompanied by more nuclear material, nuclear-related dual-use technology, and specialized equipment around the world, making it critical to encourage all countries to put in place strong safeguards, consistent with the nonproliferation priorities in the Treaty. We are committed to work with the IAEA and international partners to prevent nuclear material misuse by developing effective and affordable monitoring, detection, and verification technologies and architectures.

Addressing these challenges require us to recognize that the nuclear deterrent and nonproliferation are tightly linked, not just through capabilities that advance both stockpile stewardship and nonproliferation capabilities, but also by implementing policies that are mutually reinforcing.

The Nuclear Deterrent Enterprise

In the face of this uncertain global environment, NNSA must be responsive to the moment and the mission.

As a responsible nuclear power, the United States is committed to finding a balance between our deterrence needs and our nonproliferation obligations, and by promoting transparency. Last October, I announced the number of warheads in our nuclear weapons complex, which show that the overall size of the U.S. nuclear stockpile has decreased significantly. At the height of the Cold War, the U.S. possessed over 31,000 nuclear weapons. As of 2020, that number has shrunk to 3,750, representing an 88 percent reduction from the peak and an 83% reduction from the end of the Cold War in overall weapons, including an even higher percent reduction in nonstrategic weapons. Just to be clear, this is the total number of nuclear weapons possessed by the United States. The number of deployed strategic weapons meets the New START treaty obligation.

While we are working to further reduce the number of weapons in our stockpile, maintaining an effective deterrent requires us to execute a modernization program. Since the end of the Cold War, our programs have been centered on sustaining a capable but smaller and less diverse stockpile. Because of the age of the weapons, the U.S. embarked on a refurbishment program over a decade ago that allowed us to extend the life of weapon systems that were being retained. As the weapons continue to age, the refurbishment program needs to touch all remaining weapons and is increasingly becoming a program that fully re-builds and updates systems. The U.S. program of record also now includes a new weapon, the W93. In the absence of eliminating nuclear weapons, the future U.S. stockpile is the minimum needed to maintain a safe, secure, and effective deterrent.

The U.S. remains committed to refurbishing and modernizing our nuclear stockpile without resuming underground nuclear testing. And to be clear, we are not expanding the size of our nuclear arsenal with this modernization program, even though other nuclear weapon states are increasing both types and numbers of strategic and/or tactical nuclear weapon systems.

As we reconcile ourselves to the current global environment and our nuclear modernization plans, we also recognize the need to upgrade our production and science facilities. Infrastructure recapitalization is a critical component of the U.S. nuclear deterrent effort. Infrastructure recapitalization will replace outdated Cold-War era U.S. facilities with resilient, modernized infrastructure. The recapitalization effort will reduce the overall footprint of our nuclear weapons enterprise and provide flexibility to respond to global dynamics. Our hope is that with improved facilities and our ever-improving science-based understanding, sometime in the future we may be able reduce the number of weapons we retain in our hedge.


All that being said, make no mistake, NNSA is fully committed to our mission of preventing the spread of nuclear weapons programs while doing everything we can to promote strong nonproliferation standards as an enabler to the peaceful uses of nuclear energy. Robust safeguards and early, proactive engagement promote nonproliferation while supporting international climate goals.

 Since it is clearly better to prevent a crisis than manage it, we will work with nations and stakeholders interested in pursuing nuclear energy to incorporate nonproliferation policies into all aspects of the nuclear discussion. NNSA is investing in the people and the science, while at the same time partnering with industry and internationally, to incorporate nonproliferation standards into civil-nuclear commerce.

For example, NNSA is implementing the Proliferation Resistant Optimization program, or PRO-X, which develops proliferation resistant fuel for industrial application. In addition, together with the IAEA and international partners, we are developing a program to enhance proliferation resistance in newly-build research reactors and their related facilities. In this program, NNSA seeks to eliminate or minimize the production of nuclear material by adjusting the design of the facility before construction, while still maintaining or improving facilities’ capabilities and performance.

When it comes to enhancing the global safeguards regime, NNSA partners industry and the IAEA to demonstrate the benefits of deploying next-generation nuclear technology in a safe and secure manner. NNSA engages U.S. industry through voluntary Safeguards by Design and Security by Design efforts to address nonproliferation and security risks posed by advanced and small modular reactor designs. Through its Advanced Reactor International Safeguards Engagement, or ARISE, program, NNSA informs U.S. industry partners on international safeguards, legal requirements, and conducts technical analyses to recommend ways to integrate safeguards considerations into the design process of a new or modified nuclear facility as early as possible.

Our efforts do not stop there. NNSA works with partners around the globe to implement safeguards and reduce radiological sources and replace radioactive technologies with more proliferent-resistant options. We also partner with the medical community to provide peaceful uses assistance where it is most needed to meet development goals. We are fully committed to using our scientific and policy expertise to bring nonproliferation and the peaceful uses of nuclear energy to forefront of the global discussion.

Arms Control

Finally, let me touch briefly on arms control.

NNSA remains committed to supporting strong and verifiable future arms control agreements. Moving forward, the next generation of arms control agreements will emerge in a more complicated, unpredictable, and technologically advanced environment. The emergence of new technologies that significantly lower the barrier to proliferation, an explosion of open-source research, and the proliferation of new types of warheads and delivery vehicles all require reciprocal advancements in verification capabilities. We call on the international community to work together to address this daunting challenge. We must be proactive, rather than reactive, in addressing this issue. At NNSA, we continue to support the development and maturation of technologies in anticipation of future arms control agreements under these conditions.


As you know, this Review Conference is occurring at a pivotal moment. We must look for a balanced approach to maintaining a sufficient nuclear deterrent, advancing nonproliferation, and laying the groundwork for the next generation of arms control. This means modernizing our enterprise so that it is capable of meeting both our defense and nonproliferation needs and advancing peaceful uses. Thank you again for the opportunity to speak with you today and I look forward to your questions.