In The Green Berets “didi” is used as “go”. “Let’s didi out of here!” “Mao”, from what I remember from my Vietnamese former co-workers, is an imperitive. So “Didi mao!” would seem to mean “Go now!” or “Do it now!”
Earl…, I don’t speak Vietnamese, but have read quite a bit about the Vietnam war. I always understood “didi mau” to be an emphatic “get moving!”, but just to confirm I checked the web before offering my previous post. This glossary of military and slang terms from the war says:didi mau
slang Vietnamese for "go quickly"Checking an on-line Vietnamese-English dictionary, I see no pejorative meanings for “mau” or “mao” or any of their accented variations.
As someone who spent some time in Vietman through the courtesy of the US military, I can say that the expression would probably be spelled, “diddy mao,” or “ditty mao,” and it was pronounced DID-ee MAH-oh. (Run those last two syllables together.) It is a pidgin-Vietnamese slang expression that meant, to us, “Get the fuck out of here! Now!” or “Move your ass!”
Regardless of the precise translation of the exact words, which is actually all but irrelevant since what everyone wants isn’t really a language lesson but to know what the VC would be saying if he were speaking in English, the answer in a nutshell is he was yelling at them to “hurry! Hurry up! Do it now . . . NOW! HURRY UP! HURRY THE FUCK UP AND DO IT NOW I SAID!”. Right? Right!