856 Radio Research detachment

The 856th Radio Research Detachment was a U.S. Army unit active during the Vietnam War, specializing in signals intelligence (SIGINT) operations. Activated in the late 1960s, the detachment operated under the Army Security Agency (ASA) and worked closely with allied forces to intercept and analyze enemy communications. The 856th provided critical intelligence that supported combat operations, particularly in counterinsurgency efforts against Viet Cong and North Vietnamese Army units. Its personnel often operated in challenging field conditions, contributing significantly to the overall intelligence-gathering mission in Southeast Asia.