He received no official clearance. He just thought it up and did it.
6 seconds sound clip from the Apocalypse Now movie soundboard.
You can hear this line at 01:02:53 in the Blu-ray version of the movie.
Quote context
[...]
- Really un-fucking-believable, you know?
- Thought you might have heard by now from Elwood. I'll be coming home...
- October 1967, on special assignment, Kon Tum Province, II Corps.
- Kurtz staged Operation Archangell with combined local forces, rated a major success.
- He received no official clearance. He just thought it up and did it.
- They were gonna nail his ass to the floorboards for that one.
- But after the press got a hold of it, they promoted him to full colonel instead.
- Oh, man, the bullshit piled up so fast in Vietnam, you needed wings to stay above it.
[...]