Initially, the free fire zone was an area near an airbase which was cleared of civilians to allow aircraft bomb disposal prior to landing.
Returning veterans, affected civilians and others have said that U.S. Military Assistance Command, Vietnam MACV, based on the assumption that all friendly forces had been cleared from the area, established a policy designating the "free-fire zones" as areas in which:
Since such encounters could result in the deaths of innocent civilians, it would have been a violation of the Geneva Convention to have had such a policy.
They are less equivocal as to the fact that a "no holds barred" approach was the order of the day in many engagements. For example, during the April 25, 1971 Dellums Committee Hearings on War Crimes in Vietnam, Captian Greg Hayward, U.S. Army West Point, Class of 1964, related his experiences thusly:
I would like to tell a few personal experiences and relate them to a policy perspective and then talk a few minutes about some of the questions that have already been asked. We had an area that General Williamson considered a thorn in our side. It was called the Citadel area. It was the home of about 200 to 300 Vietnamese. We had a fire support base called Persian where your 2nd Bn, 12th Infantry, was, and General Williamson decided we were to systematically remove these people from their homes, so we could expand the free-fire zone around the FSB Persian.
We did this by having ambush patrols at night in the road networks leading in and out of the village. One of our units was given the mission to remove the villagers, the civilians from this area. They went through with armored vehicles and started burning these homes and burnings the villages in the Citadel area. The CG's guidance was not, of course, to go through and burn there was so much pressure on the commander of this battalion to perform and to accomplish his mission that I am sure in his mind that anything went.
This was a dear violation of the rules of land warfare, forcibly moving the civilian population from their homes.
Another officer, Captian Robert B. Johnson, U.S. Army, West Point, Class of 1965, related experiences corroborating the testimony of numerous returning veterans to the effect that free-fire zones, if not official policy, were widely understood as being unofficial policy conveyed by osmosis:
[Representative] SIEBERLING: You talked about the purpose of the free-fire zones. You have mentioned the fact that the free-fire zones and the harassment and interdiction fire at villagers were obviously designed to force the villagers to leave and go to resettlement areas. Did you ever hear anyone in a position of rank indicate expressly that was one of the purposes?
JOHNSON: No, I did not, because a few months after I left, there was a big report in Stars and Stripes, one area very close to us, having got 12,000 people, there was a whole operation planned where all of them at once were forcibly moved to detention camps, not by the bombings but by U.S. Marines and the ARVN troops forcibly removing them to these detention camps. That happened in June, 1968.
SEIBERLING: Did you ever hear of the expression "turkey shoots"?
JOHNSON: I have heard the free-fire zone referred to by the pilots and other people as "Indian Country."
SEIBERLING: But you are not familiar with the expression "turkey shoots"?
JOHNSON: I am familiar with it, but where I was operating I didn't hear anyone personally use that term. We used the term "Indian Country."
SEIBERLING: What did "Indian Country" refer to?
JOHNSON: I guess it means different things to different people. It is like there are savages out there, there are gooks out there. In the same way we slaughtered the Indian's buffalo, we would slaughter the water buffalo in Vietnam.
SEIBERLING: Was there any indoctrination, official or semi-officially, that incorporated the ideas that these people are gooks or that the only good gook is a dead gook or similar philosophies, or was this just something once you got there you picked it up from the other people who bad been there?
JOHNSON: I just picked it up from other people. Before I went to Vietnam, I remember one adviser who had been there before and had been through some tough straits telling me you can't trust any of these. That was not official policy.
I don't think you could find it anywhere that you can't trust the gooks in writing.
SEIBERLING: Do you have any evidence that this was so widespread that it must have been known to people at all levels of command?
JOHNSON: I don't have any specific evidence except my 6 months in the infantry division, an American unit, and the disdain and disgust of the Vietnamese was extremely widespread there.