Office of the Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs

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Nuclear Matters is the DOD focal point for the modernization and sustainment of the U.S. nuclear weapons stockpile, as well as for a wide range of nuclear counterterrorism and counterproliferation issues. Nuclear Matters is responsible for leading and integrating interagency efforts to ensure the continued credibility of the U.S. nuclear deterrent.

2022 National Defense Strategy
(including 2022 Nuclear Posture Review and 2022 Missile Defense Review)

Our Mission, Vision, and Core Principles

Mission: To ensure the continued credibility, safety, security, resiliency, and effectiveness of the U.S. nuclear deterrent to deter adversaries, assure allies and partners, and achieve U.S. objectives if deterrence fails—today and in the future.

Vision: The Office of Nuclear Matters is the trusted, go-to focal point for leading, integrating, and advancing the Department’s highest priority mission through consistent, demonstrated excellence and collaborative teamwork.

Core Principles: Nuclear Matters leadership and staff will be committed to the highest standards of public service, and will uphold the following core principles at all times Teamwork and respect Professionalism and integrity Openness and transparency Creativity and commitment


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Drew Walter

Deputy Assistant Secretary of Defense for Nuclear Matters (DASD(NM))

Photo Biography


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The Office of the Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs/Nuclear Matters (OASD(NCB/NM)) is the focal point of the Defense Department for the U.S. nuclear deterrent. In this capacity, Nuclear Matters is the primary DOD point of contact for Congress, the interagency, and the public and for allies and foreign partners on issues related to the U.S. nuclear stockpile and the integration and alignment of U.S. nuclear weapons and weapons systems. To perform these functions, Nuclear Matters is comprised of representatives from all areas of the nuclear community, including the U.S. Navy, U.S. Air Force, U.S. Army, Department of Energy (DOE)/National Nuclear Security Administration (NNSA), Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL), Sandia National Laboratories (SNL), Kansas City National Security Campus (KCNSC), and the Federal Bureau of Investigation (FBI). Nuclear Matters has a professional staff of subject matter experts in areas related to nuclear weapons stockpile management, security and incident response, technical nuclear forensics, nuclear safety and physical security, and working with allies and international organizations on issues related to the nuclear deterrent. The DASD for Nuclear Matters is a career civilian Senior Executive Service official.

Nuclear Matters has responsibilities in each of the following mission areas: nuclear safety, physical security and control; nuclear weapon incident and accident response; nuclear deterrent enterprise review; nuclear assessments; and nuclear threat prevention, protection, and response. As part of these responsibilities, the Nuclear Matters office provides support to management and oversight groups responsible for each of these mission areas including the joint DOD/DOE Nuclear Weapons Council, chaired by the Undersecretary for Acquisition and Sustainment. Additionally, the office contributes to other nuclear-related responsibilities within the DOD, to including the development of congressional testimony, providing advice on arms control and treaty issues, and participating in budgeting and planning activities related to the nuclear deterrent.


Nuclear Surety & Exercise Programs


 The Nuclear Surety and Exercise Programs (NSEP) team mission focus encompasses nuclear weapons surety (safety, security, control, personnel reliability, transportation), through overseeing and implementing the Nuclear Weapons Surety Program and providing direction for the execution of nuclear weapon-related exercises. NSEP implements safety, security, and control policies and activities that help ensure the physical and digital security of nuclear weapons and nuclear weapon systems (research, development, test , and evaluation; nuclear weapons; nuclear command and control facilities and platforms; and special nuclear materials) is maintained; prevents inadvertent or unauthorized access, use, or detonation of U.S. nuclear weapons; develops Department of Defense (DoD) nuclear weapons system safety policies; reviews/oversees Services’ nuclear weapon system safety rules; coordinates DoD personnel access to Department of Energy Sigma information; and develops Personnel Reliability Assurance Program policy.

NSEP directs and oversees the execution of exercises that validate policy, in coordination with other U.S. Government agencies and allies and in conjunction with testing and evaluating alternate nuclear physical security concepts, systems, and frameworks that could improve existing standards and meet nuclear weapon security standards.

The Director of NSEP serves as Chair of the Physical Security Enterprise and Analysis Group, which conducts research and development by investing in technology and other advanced solutions to address emerging physical security threats for DoD. Additionally, as part of efforts to pace the threat, NSEP has a team dedicated to assessing future and emerging threats (e.g., uncrewed systems with multiple domain capabilities, artificial intelligence, and autonomy).

Nuclear Weapons Council Staff


The Nuclear Weapons Council (NWC) Staff (NWCS) mission focus is the U.S. nuclear weapons capability and support to the NWC—a joint Department of Defense-Department of Energy/National Nuclear Security Administration (DOE/NNSA) body to coordinate efforts to manage the U.S. nuclear weapons stockpile. The ASD(NCB) serves as Staff Director to the NWC.

The NWC and its subordinate board, the NWC Standing and Safety Committee (NWCSSC), for which the ASD(NCB) serves as Co-Chair with DOE/NNSA, provides interagency forums for reaching consensus and establishing priorities between the two departments. The primary mission of the NWCS directorate in the Office of Nuclear Matters is to support NWC decisions, deliberations, and meetings on nuclear weapons stockpile sustainment and modernization; ensure the NWC meets its statutorily-mandated responsibilities, pursuant to title 10, Untied States Code, section 179; and serve as a focal point for the nuclear deterrent portfolio and technical assessments.

Nuclear Forensics, Energy, and Survivability

Nuclear Forensics, Energy, and Survivability

The Nuclear Forensics, Energy, and Survivability (NFES) team leads the Department of Defense (DoD) National Technical Nuclear Forensics (NTNF) Working Group, serves as the primary DoD participation in related interagency bodies, and manages research and development to develop NTNF capabilities for transition to the Services. NFES provides support to DoD nuclear forensics sample collection assets, including training exercises, and supports the DoD-managed laboratory installations at the national laboratories that conduct nuclear forensic analysis. 

In the areas of nuclear survivability and resiliency, the NFES team develops the Chemical, Biological, Radiological, and Nuclear (CBRN) survivability policy in coordination with the Office of the Deputy Assistant Secretary of Defense for Chemical and Biological Defense Programs; manages the mission critical report process; assists in developing remediation plans for survivability shortfalls; chairs the CBRN Survivability Oversight Group-Nuclear to coordinate DoD activities; serves as the Executive Secretariat for the Strategic Radiation Hardened Electronics Council; and advises the Joint Capabilities Integration and Development System Functional Capabilities Board and the Defense Acquisition Board on nuclear survivability requirements.

International Programs


The International Programs (IP) directorate’s mission focuses on international partner engagements, to include the operations and management of Mutual Defense Agreements (123 Agreements) under the Atomic Energy Act (AEA) and the U.S. Government’s (USG) responsibilities to the North Atlantic Treaty Organization (NATO) alliance. This directorate engages with foreign partners on atomic exchanges within agreed-upon governance frameworks to fortify our collective international security efforts and better inform nuclear enterprise decisions.

The IP team supports ASD(NCB) in her role as the Department of Defense (DoD) principal point of contact for cooperation with other nations on military applications of atomic energy under the AEA. Additionally, the IP team coordinates with the Department of Energy/National Nuclear Security Administration (DOE/NNSA) to manage the day-to-day activities of the USG’s international atomic agreements. The IP team also provides policy guidance to the Joint Atomic Information Exchange Group, which oversees all atomic information transfers.

The IP team supports the ASD(NCB), as Vice Chair of the NATO High-Level Group, and coordinates with Allies through the NATO Ad-Hoc Working Group and the High-Level View on U.S. nuclear weapon safety, security, and survivability. The IP team also supports ASD(NCB) on matters regarding U.S. nuclear weapons incident response by developing DoD policies and procedures, coordinating U.S. nuclear accident/incident exercises, and engaging with other USG agencies and Allies and partners.

Analytical Support and Mission Integration

Analytical Support and Mission Integration

 The Analytical Support and Mission Integration(ASMI) team manages Office of Nuclear Matters operations, budget development and execution, personnel, training, physical security, and special projects that cut across Office of Nuclear Matters directorate portfolios. ASMI serves as a focal point for congressional and external engagements, including the Government Accountability Office, Inspector General, Senior Advisory Groups (e.g., Defense Science Board, JASONS), and the Nuclear Deputy’s Management Action Group; coordinates classification reviews and Freedom of Information Act requests on behalf of the DASD(NM), the Department of Defense original classification authority for Formerly Restricted Data; leads the Office of Nuclear Matters program review and President’s Budget Request development support; and coordinates Office of Nuclear Matters operational support for DASD(NM) input into the continuity of operations plan and continuity of government planning.