Fearing the growing threat of the Viet Cong insurgency to the South Vietnamese government, President John F. Kennedy began activating special forces units in anticipation of their insurgency combat expertise in 1961. The 5th Special Forces Group was among those units activated in 1961, and while attending training at the Special Warfare Center, Kennedy visited the units and personally approved the distinctive Special Force’s Green Beret. The 5th SFG was first deployed as a battlefield advisory group for the Army of the Republic of Vietnam (ARVN). By February 1965, it was deployed as a mainstay battle force once the war was in full swing. They used unconventional and conventional warfare, and were some of the last soldiers the United States pulled out of Vietnam.
The group’s personnel in Vietnam adopted a variant flash with an added diagonal yellow stripe with three narrow red over-stripes (inspired by the flag of South Vietnam) from 1964 to 1970. The reason was that the group had a black flash bordered in white, like a funerary armband – making it look like the US had given up on their allies. From 1970 to 1985 it was adopted by the entire Group; the yellow and red stripes were officially supposed to indicate the 5th Group’s creation from personnel drawn from the 1st and 3rd Groups. It reverted to the plain black flash on 16 January 1985. On 23 March 2016, the 5th Special Forces Group changed over to the Vietnam-era flash to pay respect to the unit’s history and the Green Berets of the past who are part of the unit’s history.
In June 1969 the killing of a suspected double agent Thai Khac Chuyen, and the attempt to cover it up, led to the arrest in July of seven officers and one non-commissioned officer of the 5th Special Forces Group (Airborne) including the new commander, Colonel Robert B. Rheault in what became known as the “Green Beret Affair”. Chuyen was working with the 5th on Project GAMMA when the Green Berets learned he might be a double agent. He underwent about ten days of rigorous interrogation and solitary confinement before he was shot and dumped into the sea. National newspapers and television picked up the story, which became another lightning rod for anti-war feeling. Finally in September 1969 Secretary of the Army Stanley Resor announced that all charges would be dropped since the CIA, which may have had some involvement, refused to make its personnel available as witnesses.
In April 1970, 5th SFG began reducing its number of personnel in Vietnam. Later in November and December, further reductions in personnel and extraction of companies ensued, ending in a complete withdrawal of the group by March. On 5 March 1971, 5th SFG returned to Fort Bragg. Sixteen Soldiers assigned to or administratively assigned to 5th Special Forces Group (Airborne) during the Vietnam War were awarded the Medal of Honor; making 5th Group the most prominently decorated unit for its size in that conflict. Members of the unit continued to conduct intelligence operations in Southeast Asia until the collapse of the South Vietnamese government on 29 April 1975.
The Military Assistance Command, Vietnam – Studies and Observations Group (MACV-SOG) was a joint unconventional warfare task force created by the Joint Chiefs of Staff as a subsidiary command of the Military Assistance Command, Vietnam (MACV). The unit would eventually consist primarily of personnel from the United States Army Special Forces. Others assigned to MACV-SOG came from the United States Navy SEALs, the United States Air Force, the Central Intelligence Agency (CIA) Special Activities Division, and elements of the United States Marine Corps Force Reconnaissance units. The Studies and Observations Group was in fact controlled and missioned by the Special Assistant for Counterinsurgency and Special Activities (SACSA) and his staff at the Pentagon. After 1967 the HQ 5th Special Forces Group (Airborne), provided administrative support to MACV-SOG Special Forces soldiers in Vietnam.