This is coolbert:
Before there was Gladio there was Det A?
Detachment A Berlin, American Special Forces. Stay-behind!
From SOFREP and thanks to same.
"SPECIAL FORCES ETACHMENT A: AN ELITE COLD WAR UNIT"
"The unit was called Detachment A, with the classified name of 39th Special Forces Operational Detachment (SFOD). It was a clandestine Special Forces unit. Technically illegal under the Four Powers Agreement, Det A was on 24-hour standby in Berlin in the event that the USSR pushed over the wall from East Germany and invaded Western Europe. Secreting themselves in safe houses, the Det A members would activate once the forward line of Soviet troops passed over their positions, then carry out acts of sabotage and guerrilla warfare."
TECHNICALLY ILLEGAL! AMERICAN NATO DESIGNATED STAY-BEHIND UNIT STATIONED BERLIN. IN CASE OF WAR WITH THE SOVIET UNION THEIR MISSION TO FORM THE NUCLEUS OF AN INSURGENT GUERRILLA WARFARE MOVEMENT.
"In a stay-behind operation, a country places secret operatives or organizations in its own territory, for use in the event that an enemy occupies that territory. ... Small-scale operations may cover discrete areas, but larger stay-behind operations envisage reacting to the conquest of entire countries."
See also Part 2, Part 3, Part 4. Interesting how a mission for these elite units changes over the decades.