"Winter Soldier," which opened at the Whitney Museum yesterday as part of its New American Filmmakers Series, is a documentary feature composed entirely of Vietnam veterans' testimony, most of which was photographed and recorded during hearings in Detroit, Jan. 31-Feb. 2, 1971, sponsored by the Vietnam Veterans Against the War.

It includes occasional official newsreel clips, as well as still photographs supplied by the testifying veterans (including one Brownie snapshot of a triumphant, smiling G.I. standing at the head of a newly murdered Vietnamese), but it is most agonizing in its young, barely molded words and faces–the record of men trying to make some sense of an experience that to them clearly makes no sense. Yet something very important is missing from the movie and, by extension it seems, from what might be called the American character.

The movie is an oral history, told by former United States soldiers, sailors and marines who, for the most part, admit to having participated in various atrocities without question. What is obviously missing–and I suppose this is hardly news now–is some explanation as to how we could have managed to raise a couple of generations of people who could participate in the conduct described without experiencing the kind of sorrow that activates conscience. This, I assume, is the question that the film intends to raise.

The other question, which is as much a moral question as a dramatic one, is what happened to change these men’s minds, and when? At what point, for example, does a man, who could pose with the corpse of someone he has just shot, decide that he doesn’t want to do this anymore? About halfway through "Winter Soldier" there is a moment that tells us about all the stories we are not hearing, when a clean-cut former G.I. recalls walking down a street in Cambridge and going out of his way to push a bearded student off the sidewalk. The student, he remembers, said simply: "You make it very difficult for anyone to get to know you."

The former soldier then says something on the order of: "I told my wife about this, and she helped me straighten my head out."

That is as close as "Winter Soldier" ever comes to providing an obligatory scene. The other conversions are unremembered. They take place silently, off-screen. All of which effectively limits the larger purposes of "Winter Soldier," even for one who is sympathetic to its ends. I suspect that one of the reasons that what happened could happen is that we live in a culture whose slang, among other things, persists in referring to the mind as the head. We refuse to make distinctions that can, in the long run, recognize the difference between life and death.

This devastating documentary was shunned by TV networks and theatrical distributors in 1972. At the height of the Vietnam War, more than 100 honorably discharged, and in some cases highly decorated, veterans gathered in Detroit to put their denunciation of the war on the record, detailing horrors they witnessed firsthand or personally committed.

The event was organized by recently returned veteran John Kerry and other antiwar activists such as Jane Fonda and Dick Gregory. The purpose was to tell the American public about the ugly realities of the war and to let the soldiers unburden themselves. For more than three decades, the film has been the subject of rumor, speculation and controversy: It erupted again during the last presidential campaign. Now it is finally receiving a limited nationwide release, a time capsule from a painful chapter in U.S. history that eerily foreshadows recent shameful episodes such as the torture of prisoners at Abu Ghraib.

The presentation is documentary filmmaking at its most basic. Eyewitnesses address the camera, recounting what they have seen. They tell of children being shot dead for mild acts of rudeness, hamlets being blasted by artillery as part of a drinking game and bound prisoners routinely being thrown from aircraft, all with the full awareness of officers at all levels. Capt. Rusty Sachs, a former Marine helicopter pilot, recounts being ordered not to "count prisoners when you’re loading them on the aircraft; count them when you're unloading them [because] the numbers may not jibe."

For many of those testifying, the line between war and murder was blurred to insignificance.

One soldier said his rules of engagement with unknown Vietnamese were, "If they run, they're [Viet Cong soldiers]. Shoot ‘em. If they stay, they’re well-disciplined V.C. Shoot ‘em anyway."

This carnage was carried out not by demented killers, but by men who were conspicuously normal.

The testimony offered in "Winter Soldier" has been criticized as a litany of left-wing clichés about the Vietnam War. Writing about the film in the National Review, Mackubin Thomas Owens, a professor at the Naval War College who led a Marine infantry platoon in Vietnam from 1968 to ‘69, asserted that many self-described veterans were actually imposters who had never seen combat. See it and judge for yourself. Whatever you conclude, there’s no doubt that "Winter Soldier" is a powerful document from a painful chapter in history.

Shot in three days in the winter of 1971 at a Detroit conference convened by Vietnam Veterans Against the War, Winter Soldiers is a grainy black-and-white documentary in which several dozen American ex-servicemen, among them the 28-year-old John Kerry, recall the atrocities they heard of, witnessed or, in some cases, took part in during their time in Vietnam. It establishes that far from being the exception, incidents like the My Lai massacre were everyday occurrences. The film was scarcely seen in America, though the FBI put its makers under surveillance (this was Watergate time). It should be obligatory viewing for anyone joining the American armed forces.

Like Peter Davis’s Hearts and Minds and Michael Moore’s Fahrenheit 9/11, Winter Soldier is less documentary than in-the-heat-of-conflict document, too close to the bone for "distance." No less a wake-up call, however, the film dispenses with their indoctrinating montage to focus more plainly on the raw material and rawer nerves of its subject–namely the atrocities committed by U.S. soldiers during the Vietnam War, given voice in the historic testimony by more than 125 ex-Gis at the Detroit Winter Soldier Hearing in 1971. The first time ‘Nam vets publicly testified about their experiences, the event was briefly glimpsed in last year’s doc Going Upriver: The Long War of John Kerry and indeed a 28-year-old Kerry puts in a quick appearance early on, though the grainy lenses remain squarely, as they should, on the men trying to come to terms with the horrors they have seen and committed abroad.

The testimonies build up a mosaic of carnage before a stunned audience, or, as Amos Vogel put in a vintage Village Voice review, "a criminal, cosmic jigsaw puzzle"-Vietnamese prisoners thrown out of helicopters as part of bets among grunts, women raped and disemboweled, villages burned down to "show we’re not fucking around," children blasted for giving the soldiers the finger, ears and limbs sliced off to boost the body count. Shot in vérité black and white in deliberate auteur-anonymity (footage was supplied by 12 activist-filmmakers, including future acclaimed documentarian Barbara Kopple), the film opens on a Thomas Paine quote ("These are times that try men's souls") and proceeds to extract startling political points from the soldiers’ devastating speeches, an indictment of the institutionalized indoctrination of bloodlust emerging out of a former grunt’s off-the-cuff comment about masculinity ideals enforced since school ("I wanted to see for myself whether I’m a man or not").

The old word vs. image argument might be brought up apropos of Winter Soldier’s "artlessness," yet the fact remains that Private Camil’s first, frontal close-up, recounting boot-camp training up to his first kill overseas, compresses all of Full Metal Jacket into seven minutes. Ultimately, the film’s trajectory is spiritual as well as political ("Won’t you forgive me for my sins," goes the blues refrain over the final credits); the men, their robotic crewcuts since grown into beards and manes, come together for a therapeutic, even exorcizing, moment of communal demons acknowledged and transcended. Numbness to the suffering of others may give way to healing tears and even an understanding of the racial and historical aspects of the issue (voiced by a pissed-off Black Panther and a tearful Native American), though judging from our current involvement in the Middle East, history seems to inevitably repeat itself. "The more things change," and all that, yet it is fitting that one of the screen’s strongest antiwar tracts arrived at the beginning of a nation’s most self-inquiring decade, when the medium could be seen as capable of inciting change.