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.