Orange Crush was an orange flavored soft drink. In this case, though, it was meant to refer to Agent Orange, a chemical used by the US to defoliate the Vietnamese jungle during the Vietnam War. US military personnel exposed to it developed cancer years later and some of their children had birth defects. The extreme lyrical dissonance in the song meant that most people completely misinterpreted the song, including Top Of The Pops host Simon Parkin, who remarked on camera after R.E.M. performed the song on the British TV show, "Mmm, great on a summer's day. That's Orange Crush."
The song does not refer to any single Vietnam-related experience for lead singer Michael Stipe, but simply that he lived in that era of American history. He wrote in Part Lies, Part Heart, Part Truth, Part Garbage 1982-2011: "[The song is] a composite and fictional narrative in the first person, drawn from different stories I heard growing up around Army bases. This song is about the Vietnam War and the impact on soldiers returning to a country that wrongly blamed them for the war."
Stipe's father served in Vietnam in the helicopter corps.
Stipe sometimes introduced this in concert by singing the US Army jingle, "Be all that you can be, in the Army."
The drill sergeant heard in the background during the middle is just an imitation by Stipe. In the traditional Michael Stipe way, the words he says during the imitation are complete nonsense.
This was not the first R.E.M. song to deal with the Vietnam War. That distinction goes to "Body Count," an early unreleased song that they played live many times.
This was used in the 2007 drama Towelhead, starring Maria Bello, Chris Messina and Summer Bishil.
The song's meaning keeps changing for Peter Buck. He wrote in the In Time liner notes:
"I must have played this song onstage over three hundred times, and I still don't know what the f*** it's about. The funny thing is, every time I play it, it means something different to me, and I find myself moved emotionally. [Playwright/composer] Noel Coward made some remark about the potency of cheap music, and while I wouldn't describe the song as cheap in any way, sometimes great songwriting isn't the point. A couple of chords, a good melody and some words can mean more than a seven-hundred-page novel, mind you. Not a good seven-hundred-page novel mind you, but more say, a long Jacqueline Susann novel. Well alright, I really liked Valley of the Dolls."