The Office of the Secretary of Defense (OSD) is a headquarters-level staff of the United States Department of Defense. It is the principal civilian staff element of the U.S. Secretary of Defense, and it assists the Secretary in carrying out authority, direction and control of the Department of Defense in the exercise of policy development, planning, resource management, fiscal, and program evaluation responsibilities. OSD is the Secretary of Defense's support staff for managing the Department of Defense, and it corresponds to what the Executive Office of the President of the U.S. is to the U.S. president for managing the whole of the Executive branch of the federal government.
The United States under secretary of defense for policy (USDP) is a high level civilian official in the United States Department of Defense. The under secretary of defense for policy is the principal staff assistant and adviser to both the secretary of defense and the deputy secretary of defense for all matters concerning the formation of national security and defense policy.
The under secretary of defense for intelligence and security or USD(I&S) is a high-ranking civilian position in the Office of the Secretary of Defense (OSD) within the U.S. Department of Defense (DoD) that acts as the principal civilian advisor and deputy to the secretary of defense (SecDef) and deputy secretary of defense (DepSecDef) on matters relating to military intelligence and security. The under secretary is appointed as a civilian by the president and confirmed by the Senate to serve at the pleasure of the president.
The under secretary of defense for personnel and readiness, or USD (P&R) is a high-ranking civilian position in the Office of the Secretary of Defense (OSD) within the United States Department of Defense responsible for advising the secretary and deputy secretary of defense on recruitment, career development, pay and benefits, and oversight of the state of military readiness. The under secretary is appointed from civilian life by the president and confirmed by the Senate to serve at the pleasure of the President.
The Under Secretary of Defense for Acquisition and Sustainment, or USD (A&S), is the Principal Staff Assistant (PSA) and advisor to the Secretary of Defense for all matters relating to acquisition and sustainment in the Department of Defense. This includes the DoD Acquisition System; system design and development; production; logistics and distribution; installation maintenance, management, and resilience; military construction; procurement of goods and services; material readiness; maintenance; environment and energy resilience ; utilities; business management modernization; International Armaments Cooperation, Cooperative Acquisition and International Agreements, Promoting exportability of military components to allies and partners; nuclear, chemical and biological defense programs; and nuclear command, control, and communications.
The Assistant Secretary of Defense for Health Affairs (ASD(HA)) is chartered under United States Department of Defense Directive (DoDD) 5136.1 in 1994. This DoDD states that the ASD(HA) is the principal advisor to the U.S. Secretary of Defense on all "DoD health policies, programs and activities." In addition to exercising oversight of all DoD health resources, ASD(HA) serves as director of the Tricare Management Activity.
The Assistant to the Secretary of Defense for Public Affairs, or ATSD (PA), is the principal staff advisor and assistant to the Secretary of Defense and Deputy Secretary of Defense for public information, internal information, community relations, information training, and audiovisual matters in support of Department of Defense activities, leading a worldwide public affairs community of some 3,800 military and civilian personnel. The Assistant to the Secretary follows the Secretary's Principles of Information in providing Defense Department information to the public, the United States Congress and the media.
The Under Secretary of Defense for Research and Engineering, abbreviated USD (R&E), is a senior official of the United States Department of Defense. The USD (R&E) is charged with the development and oversight of technology strategy for the DoD. The post has at various times had the titles Assistant Secretary of Defense for Research and Engineering, or Director of Defense Research and Engineering (DDR&E). The latter title has itself historically varied between the rank of under secretary and that of assistant secretary.
The Assistant Secretary of Defense for Nuclear, Chemical & Biological Defense Programs, or ASD(NCB), is the principal adviser to the Secretary of Defense, Deputy Secretary of Defense and the Under Secretary of Defense for Acquisition and Sustainment on policy and plans for nuclear, chemical, and biological defense programs.
The Assistant Secretary of Defense for Global Strategic Affairs, or ASD(GSA), is a position in the Office of the Secretary of Defense that develops policy for the Secretary on countering weapons of mass destruction, nuclear forces and missile defense, cyber security and space issues. ASD(GSA) is currently tasked with three major congressionally mandated reviews: the Nuclear Posture Review, the Ballistic Missile Defense Review, and the Space Posture Review. In addition, GSA is the Defense Department's lead in developing the DoD's cybersecurity strategy, and for crafting the policy for the standup of the new Cyber Command. ASD(GSA) answers to the Under Secretary of Defense for Policy. Although ASD(GSA) is a recently configured office, its functional responsibilities can be traced back in part to a position eliminated in early 2008, the 'Assistant Secretary of Defense for International Security Policy'
In the United States military, the Assistant Secretary of Defense for Manpower and Reserve Affairs(ASD ), formerly Assistant Secretary of Defense for Reserve Affairs(ASD ) serves as Principal Staff Assistant and advisor to the Secretary of Defense, Deputy Secretary of Defense and Under Secretary of Defense for Personnel and Readiness, with responsibility for "overall policies and procedures of [U.S.] Total Force manpower, personnel and reserve affairs," including the Army National Guard, Army Reserve, Navy Reserve, Marine Corps Reserve, Air National Guard, Air Force Reserve and Coast Guard Reserve. The ASD (M&RA) reports directly to the Under Secretary of Defense (P&R) and exercises authority, direction, and control over the National Committee for Employer Support of the Guard and Reserve. On September 16, 2022, President Biden announced his intent to nominate Ronald Keohane to the position.
The Assistant Secretary of Defense for Indo-Pacific Security Affairs, or ASD (IPSA), is the principal advisor to the Under Secretary of Defense for Policy (USD(P)) and the Secretary of Defense on international security strategy and policy on issues of DoD interest that relate to the governments and defense establishments of the nations and international organizations within the Indo-Pacific region. It primarily includes the entire region from India to Japan, and the region where ASEAN is located. The position was originally titled Assistant Secretary of Defense for Asian and Pacific Security Affairs but was renamed by the first Trump Administration alongside the renaming of the United States Indo-Pacific Command.
The Assistant Secretary of Defense for Readiness and Force Management, or ASD(R&FM), is a Defense Department position responsible for civilian and military personnel policy, readiness of the force, military community and family policy and diversity management and equal opportunity.
The Assistant Secretary of Defense for Sustainment (ASD (Sustainment)), formerly known as the Assistant Secretary of Defense for Logistics and Materiel Readiness (ASD(L&MR)), is one of three assistant secretaries reporting to the Under Secretary of Defense for Acquisition and Sustainment. Formerly the position was an adviser to the Under Secretary of Defense for Acquisition, Technology and Logistics, Deputy Secretary of Defense, and Secretary of Defense on logistics and materiel readiness issues within the Department of Defense (DoD), including programs related to logistics, materiel readiness, maintenance, strategic mobility, and sustainment support. As the principal logistics official within the senior management of the DoD, the ASD(Sustainment) exercises authority, direction and control over the director of the Defense Logistics Agency. Like all other Assistant Secretaries of Defense, the ASD(Sustainment) is considered a part of the Office of the Secretary of Defense.
The Assistant Secretary of Defense for Energy, Installations, and Environment, concurrently the Chief Sustainability Officer, and formerly known as the Deputy Under Secretary of Defense for Installations and Environment, provides management and oversight of military installations worldwide and manages environmental, safety, and occupational health programs for the Department of Defense (DoD). DoD's installations cover some 29,000,000 acres (120,000 km2), with 539,000 buildings and structures valued at more than $700 billion. The responsibilities of the ASD(EI&E) include the development of installation capabilities, programs, and budgets; installation-energy programs and policy; base realignment and closure; privatization of military housing and utilities; and integration of environmental needs into the weapons acquisition process. The ASD(EI&E) is also responsible for environmental management, safety and occupational health; environmental restoration at active and closing bases; conservation of natural and cultural resources; pollution prevention; environmental research and technology; fire protection; and explosives safety. The ASD(EI&E) reports to the Under Secretary of Defense for Acquisition and Sustainment, and is a part of the Office of the Secretary of Defense.
Linton Wells II is an American public servant and educator who served a total of 51 years in government service. He served 26 years in the United States Navy as an officer, and then was appointed by the President of the United States as the Principal Deputy Assistant Secretary of Defense, serving through two administrations of both parties, both the Democrat Bill Clinton and the Republican George W. Bush. He wrote many books, articles, and white papers on matters of national security, including important texts related to the use of American military capabilities in global humanitarian operations. His expertise focused on the strategic impacts of technological change and on building resilience to natural and man-made disasters as issues of US national security. He shaped, over five decades of public service, current US Department of Defense directives that link policy and technology with public-private cooperation. His writings significantly altered U.S. and international approaches to civil-military engagement, US policy in global humanitarian assistance, and global public-private partnerships in disaster relief. He has also made fundamental contributions to technical areas that have defined network-enabled military capabilities and cyberspace operations. After retiring from public service, he continued to contribute to the international STAR-TIDES network that he had founded in 2007, a consortium of several thousand global nodes comprising agencies, organizations, institutions and individuals in 40+ countries that promote the free exchange of research results on global issues of human security. As of 2024 he is Executive Advisor to the Center for Resilient and Sustainable Communities (C-RASC) at George Mason University and chairs the Advisory Group of the C4I and Cyber Center there. C-RASC has been working with the People-Centered Internet (PCI) on ways to “put humanity at the center of the Internet” and support a variety of revitalization initiatives. He is on the board of PCI, and also the President and CEO of Global Resilience Strategies and Senior Advisor to Resilient Japan. He was listed by Fortune magazine in 2009 as one of the top 16 "Players of Tech".
The National Defense Strategy (NDS) is produced by the United States Office of the Secretary of Defense (OSD) and is signed by the United States Secretary of Defense as the United States Department of Defense's (DoD) capstone strategic guidance. The NDS translates and refines the National Security Strategy (NSS) into broad military guidance for military planning, military strategy, force posturing, force constructs, force modernization, etc. It is expected to be produced every four years and to be generally publicly available.
The Assistant Secretary of Defense for Acquisition, or ASD (A), is one of three assistant secretaries reporting to the Under Secretary of Defense for Acquisition and Sustainment. The position is the principal advisor to the Under Secretary of Defense for Acquisition and Sustainment, the Deputy Secretary of Defense, and the Secretary of Defense on matters relating to acquisition program management; the Department of Defense Acquisition System; and the development of strategic, space, intelligence, tactical warfare, command and control, and business systems.
The Space Rapid Capabilities Office is a Direct Reporting Unit of the United States Space Force which specializes in the expedited development and rapid production and deployment of space capabilities to fulfill short-term critical needs. The relatively small and unique office's work is directed by requirements for capabilities provided by the Commander of United States Space Command, and aims to provide capabilities responsive to a request within 1 to 3 years.
