I was startled because that student's question seemed so distant and remote, as open and objective as if he were inquiring about Antietam or Bull Run. I thought of that student again this week: how it may be impossible for him, or anyone born after the last American helicopters left Saigon in 1975, to fully grasp the unexpectedly raw emotions unleashed -- visible on op-ed pages and talk shows -- by the revelation that recently retired Sen. Bob Kerrey, as a young Navy SEAL lieutenant, participated in a massacre of 13 unarmed Vietnamese women and children in February of 1969.

When the film "Saving Private Ryan" opened, veterans' hospitals reported an upsurge in elderly World War II soldiers seeking treatment for post-traumatic stress disorder for the first time in their lives. Something like that has happened with the story of the encounter between then-Lt. Kerrey's eight-man commando squad and the people of Thanh Phong.

After decades in which many politicians have done their best to gloss over the lingering damage done by the war in Vietnam, the Kerrey story demonstrated that the books are far from closed, either in the private realm of emotion or the public balance sheet of moral accountability.

The story of Thanh Phong and the squad who called themselves Kerrey's Raiders proves something that the ancient Greeks would have understood: that an atrocity unacknowledged and papered over festers like a body unburied, erasing time and space between the original event and revelation of the terrible secret. In the scales of the Vietnam War Thanh Phong is a tiny and obscure incident, yet this Sunday's New York Times Magazine story, like a post-traumatic flashback, instantly opened up yawning divisions over the war, sending a surge of once-familiar language through the national adrenaline system of the media: hooches and body counts and strategic hamlets and VC.

That's certainly true for Kerrey's Raiders, who after 32 years are for the first time actively revisiting the events of that night, beginning to sort out facts with what appears to be the full gamut of human expression from profound "shame" (Kerrey's word) to defensiveness to anger. It appears to be true in Thanh Phong, where one surviving villager named Pham Tri Lanh told a CBS camera crew the story that 32 years earlier village elders tried to communicate to U.S. Army investigators -- who promptly covered up what military records called the "alleged atrocities."

That abrupt upwelling of emotion goes beyond the immediate participants and survivors. Looking at the press the last few days you'd think the war had never ended -- the terms of debate thrust back decades. In the New York Times, William Safire -- President Nixon's speechwriter at the time of Thanh Phong -- excoriates postwar American self-flagellation and defends the war as nobly motivated; Time magazine worries over the consequences for American soldiers if they are sent into battle without proper justification, a framework unchanged since 1975.

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