By Gregory L. Vistica

Thomas Dunne. 296 pp. $24.95

"Basically you're talking about a man who killed innocent civilians," says former U.S. senator Bob Kerrey of himself in this new book about his Vietnam war record and his life in politics. That is as close as Kerrey comes to confirming Gregory L. Vistica's charge that the Congressional Medal of Honor winner from Nebraska, now president of the New School in New York, may have committed war crimes when he was 25 and should now be investigated for it.

While Kerrey acknowledges that "something really bad had come from me" during a nighttime raid on a Vietnamese village in 1969, he is far from admitting to the grisly, and possibly incriminating, version of events that at least one former member of his Navy SEAL team remembers. Therein lies the challenge of this extremely well-researched but Rashomon-like book about the horror of the night of Feb. 25, 1969, in Thanh Phong, a village in the Mekong delta.

The village was identified as a Vietcong stronghold, and Kerrey's SEALs -- the Navy version of special forces -- were sent to overrun a meeting of key officials that was supposed to take place that night. Instead, they stumbled on two groups of civilians -- four in one spot, 21 in another -- and killed almost all of them (at least one little girl survived). In this book, there are at least two versions of what happened that night, one clear and stomach-turning, the other more nebulous, shifting, non-incriminating.

In the version favored by Vistica, Kerrey ordered what amounted to a massacre of two dozen women and children and one old man to cover the retreat of his six men after a botched mission. The author's chief source is Gerhard Klann, a SEAL who claimed to remember Kerrey helping him slit the throat of the old man in the first group of civilians. Klann says the team then found the second group -- all women and children -- in a nearby clutch of huts and bunkers. The men gathered them together and then, on Kerrey's command, raked them with a barrage of more than 1,000 bullets. "We just virtually slaughtered those people," Klann told Vistica. "There was blood flying up, bits and pieces of flesh hitting us." Klann says that when moans were heard afterward, more shots were fired until all was quiet.

In Kerrey's version -- which changed slightly over the two-and-a-half years of conversations he had with Vistica and several other journalists -- the first four civilians were all males and were killed without his assistance; in one telling, he said they were armed. The others were mowed down as they poured out of a group of huts from which shots had been fired at the Americans, causing them to shoot back. (In his autobiography, When I Was a Young Man, Kerrey tells it slightly differently, saying the villagers were caught in a "crossfire.")

The other five SEAL team members ultimately supported a variation of this version in a statement they signed in April 2001 just as Vistica's story, with Klann's allegations, appeared in the New York Times Magazine and on CBS's "60 Minutes II." Of Klann's claims that women and children were rounded up and shot, they wrote, "That simply is not true."

The second version is contradicted by some of the evidence that Vistica amassed over four years of investigative reporting that included, near the end, two eyewitness accounts by Thanh Phong villagers. It also conflicts in some details with more than a score of conversations, phone calls, e-mails and a train-ride interview with Kerrey, who abandoned what appeared to be a plan to run for president in 1998 after first being confronted with Vistica's information. As the author tells the story of his investigation, he gradually moves from what he claims was initial skepticism of the possible culpability of the well-liked Nebraska senator, who had a reputation for candor in Washington, to the conviction that he was lying.

Judging the conflicting versions of events in this complicated, well-sourced book is difficult. It's easy to be overwhelmed by the sheer mass of Vistica's evidence. Klann's story, in Vistica's telling, has a coherence and consistency (he had related it in private, with the same details, to a Naval officer 10 years earlier) that the other versions don't. The author, a former national security correspondent for Newsweek who now works as a producer for "60 Minutes II," even reaches back to Kerrey's pre-Washington career as a Nebraska businessman and governor to paint a portrait of the politician as a dissembler prone to flip-flops and stories changed for political convenience. Yet that conclusion may be the sort that is easy to draw about many elected officials who have fought tough political campaigns and made their share of enemies. The reader is finally forced to remind himself what he doesn't know: exactly what the other SEAL team members would recall if they were willing to talk. Most refused to speak in detail to Vistica, keeping their traditional code of silence. And they did sign that denial.

Like the characters gathered under the Rashomon Gate in Kurosawa's 1951 movie, the seven then-young men who swept into Thanh Phong may have honest differences of memory, so that one true version of what happened does not exist. Kerrey even says as much. "You have shaken my confidence that I know what the truth is," he told a CBS producer, who related the conversation in an e-mail to Vistica. Later, on the air with Dan Rather, Kerrey denied that he had committed a war crime but said that the killings at Thanh Phong could probably be called an "atrocity."

The weight of Vistica's evidence is somewhat diminished when he finally shows his cards in the epilogue. He writes of Kerrey, "He is not a hero, and he can be, as many politicians become, a user and a person who does not have enough of a conscience to be a truth teller." That's a full-frontal denunciation; it would have served readers better to have read this in the prologue, not on page 271.

Despite its unresolved questions, this compelling book has the virtue of starkly recalling us of the excesses of that misbegotten jungle war, and will be chillingly realistic to anyone who saw parts of it. The failure to investigate the details of the Thanh Phong raid at the time -- a report of possible wrongdoing went up the chain of command, but there was no follow-up -- is a sobering reminder, in this era of impending hostilities, of the importance of accountability, even in the fog of war. *

Peter Ross Range, a former Time Magazine correspondent in Vietnam, covered the My Lai massacre trial of William L. Calley in 1970-71.

Former Senator Bob Kerrey on CBS's "60 Minutes II"; at right, Bui Thi Luom, one of the survivors of the 1969 raid in Thanh Phong, a village in the Mekong delta, where many civilians were killed.