The Defense Attaché Office, Saigon (also known as DAO, Saigon or simply DAO) was a joint-service command and military attaché branch of the United States Department of Defense (DOD) under the control of United States Support Activities Group (USSAG). It assumed all DOD responsibilities in South Vietnam following the disestablishment of Military Assistance Command, Vietnam (MACV) in March 1973. The DAO was responsible for administering military assistance and support to the South Vietnamese armed forces, the gathering and distribution of military intelligence and the performance of normal Defense Attaché functions. The DAO remained in existence until August 1975.