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

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"The number one priority of the Department of Defense is that we maintain a safe, secure, and effective nuclear deterrent so we make certain those weapons are never used."

Former Secretary of Defense Mattis, August 2017

2022 Nuclear Posture Review (NPR) Fact Sheet

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.

Our Mission and Vision

Mission: To ensure the continued credibility, effectiveness, safety, and security of the U.S. deterrent in order to deter nuclear and non-nuclear attack; assure U.S. allies and partners; achieve U.S. objectives if deterrence fails; and hedge against an uncertain 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, teamwork, and integrity.


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Drew Walter

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

Photo Biography


NM Organization Chart


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 (NSE) team covers mission focus areas encompassing nuclear weapons surety (safety, security, control, personnel reliability, transportation), intelligence and threat assessments, and nuclear physical security (RDT&E, nuclear weapons, NC2 facilities & platforms, and special nuclear materials) including the relevant management and oversight groups.

NSE Implements safety, security, and control policies and activities that help ensure there will be no nuclear weapon incidents, unauthorized detonations, or degradation of weapon performance during its stockpile-to-target sequence; develops DOD Nuclear Weapons System Safety Policies and review/ oversee Services nuclear weapon system safety rules; coordinates all DOD personnel access to DOE Sigma information; and develops Personnel Reliability Assurance Program policy. NSE develops DOD policy on nuclear physical security; coordinates with U.S. Government agencies & Allies on physical security issues; directs the DOD Force on Force, Prominent Hunt, and Nuclear Accident Incident Exercise programs; oversees physical security research, development, test, and evaluation investment; focus on solving DOD-wide issues ($40M program); and address emerging threats including countering unmanned systems.

Nuclear Weapons Development & Assessments


The Nuclear Weapons Development and Assessments (NWDA) team mission focus is the U.S. nuclear weapons capability including support to the Nuclear Weapons Council (NWC). The ASD(NCB) serves as the Staff Director to the NWC, a joint DOD, Department of Energy/National Nuclear Security Administration (DOE/NNSA) body to coordinate efforts to manage the U.S. nuclear weapons stockpile.

The NWC, and its subordinate board the NWC Standing and Safety Committee (NWCSSC) for which the ASD(NCB) serves as Co-Chair with NNSA, provide an interagency forum for reaching consensus and establishing priorities between the two departments. The primary mission of the NWDA office within Nuclear Matters is to staff the NWC decisions, deliberations, and meetings in support of the nuclear weapons stockpile sustainment and modernization; ensure the NWC meets its statutory required responsibilities, pursuant to 10 USC Section 179; and serves as a focal point for nuclear deterrent portfolio and technical assessments.

International Nuclear Programs, Nuclear Forensics, Resiliency, and Survivability


The International Nuclear Programs, Nuclear Forensics, Resiliency, and Survivability (INP&NFRS) team leads the DOD National Technical Nuclear Forensics (NTNF) Working Group and serves as the primary DOD participation in interagency bodies; supports technical exchanges with the United Kingdom and France; and manages R&D to develop NTNF capabilities for transition to DOD Services.

In the area of nuclear survivability and resiliency the INP-NFR&S team develops the Chemical, Biological, Radiological, Nuclear (CBRN) survivability policy in coordination with DASD(CBD) ; manages the Mission Critical Report (MCR) process; assists in developing remediation plans for survivability shortfalls; chairs the CBRN Survivability Oversight Group-Nuclear (CSOG-N) to coordinate activities in the DOD; serves as the Executive Secretariat for the Strategic Radiation Hardened Electronics Council (SRHEC); and advises the Joint Capabilities Integration and Development System Functional Capabilities Board and the Defense Acquisition Board on nuclear survivability requirements.

INP-NFR&S provides support to the ASD(NCB) as the DOD lead for Atomic Energy Act (AEA) exchanges with International partners including the U.S./UK 1958 Mutual Defense Agreement (MDA) and the U.S./France 1961 Mutual Defense Agreement for Cooperation. INP-NFRS also coordinates with DOE-NNSA to provide policy guidance to the Joint Atomic Information Exchange Group, which oversees all U.S. Atomic Energy information transfers.



The NATO and U.S. Incident Response mission focus is on NATO nuclear safety, surety, survivability, and deterrence as well as incident response policy and training and nuclear accident/incident agreements. The NATO-IR team supports the ASD(NCB) as the 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 ASD(NCB) serves as technical advisor to the Secretary of Defense on matters of U.S. nuclear weapon incident response; develops DOD policies and procedures for responding to U.S. nuclear weapons accidents and incidents; coordinates U.S. nuclear weapon accident/incident exercises, within DOD and with other U.S. Government agencies and NATO allies; and chairs the Nuclear Weapon Accident/Incident Response Subcommittee; and supports the Security and Incident Response Council (SIRC).

Analytical and Enterprise Support Program Integration


The Analytical & Enterprise Support and Program Integration (A&ESPI) team manages the Nuclear Matters office operations; budget development and execution; personnel; scheduling; training; correspondence and records management; office safety and security; and special projects that cut across directorate portfolios. A&ESPI serves as a focal point for Congressional and external engagements, including the Government Accounting Office, Inspector General, and Senior Advisory Group (e.g., Defense Science Board, JASONS) activities; coordinates classification reviews and Freedom of Information Act (FOIA) requests on behalf of the DASD(NM)—the DOD original classification authority for Formerly Restricted Data; leads the Nuclear Matters Program Review and Presidential Budget Request development support; and coordinates the Nuclear Matters office operational support for ODASD(NM) input into the Continuity of Operations Plan and Continuity of Government planning.