Some years ago I gathered some friends and journalists for an evening with Hugh Thompson. He was the American warrant officer who, in Vietnam, had hovered his helicopter over a group of American GIs who were massacring the villagers of My Lai and forced an end to the slaughter. After Thompson spoke, someone asked why I, a hawk on Vietnam, had organized such an evening. I explained that I felt it is important for the hawks especially to confront the lapses on our own side. And to remember that even though My Lai was committed by Americans, it was also ended by Americans.

This is how I feel about Philip Gourevitch’s new book, “Standard Operating Procedure” (Penguin Press, 304 pages, $25.95), an account of the prison in Iraq known as Abu Ghraib. Mr. Gourevitch is one of a group of brilliant reporters who started at the Jewish Forward newspaper in the 1990s. Now editor of the Paris Review, he won a National Book Award for “We Wish To Inform You That Tomorrow We Will Be Killed With Our Families,” his book on the genocide at Rwanda. His new book is a collaboration with the filmmaker Errol Morris, who made the film “Standard Operating Procedure,” about what happened in the prison from which the infamous photographs emerged of prisoners being mistreated by their American captors.

Mr. Gourevitch opens the story with a description of Saddam Hussein’s release, in October 2002, of inmates of Abu Ghraib — ostensibly a gesture to thank the people who had “elected” Saddam to a new term in a charade of an election a few days earlier. Mr. Gourevitch describes the outpouring from the prison of thousands, “harrowed, unwashed, weeping, clutching the foul bedrolls that were their only belongings … ” Writes Mr. Gourevitch: “Saddam’s prisons were the engine houses of his power, factories of terror and annihilation” in which there was “no limit to the torture.” The scene makes the point that whatever was to follow during the American administration of Abu Ghraib, it was different than what happened under Saddam.

What did follow under the Americans, though, was bad enough, all the more so because it was such an affront to American law and morals — and to our effort to win the Battle of Iraq. The book is particularly deft in describing the way the stage was set, with inexperienced military police and military intelligence personnel overwhelmed by the scale of the prison operation, by the urgency of extracting military intelligence from prisoners arriving by the truckload, and by the stress that combat placed on those running the prison and handling the very prisoners who, at least in some cases, had been involved in levying attacks against them.

It was into this cauldron that the Army assigned a corporal named Charles Graner and a young private first class named Lynndie England. She had become involved in a sexual relationship with Graner even before their military police unit was transferred to Iraq, and things went downhill from there. They were by no means the only two Americans involved in the mistreatment of prisoners in Abu Ghraib, but they are two of the most infamous. It was England who is quoted by Mr. Gourevitch as using the phrase “standard operating procedure” to describe the sexual humiliation of prisoners at Abu Ghraib.

The book is not a typical historical work, in which a complete array of sources and interviews is used to construct the narrative. It does not use real names for the prisoners, though it does use the nicknames given to them by their American jailors. But it gives a graphic account of the mistreatment involved in several of the now-infamous photographs that emerged from Abu Ghraib — the stacking of naked inmates, the dog terrorizing a naked prisoner, the prisoner standing on a box with a sandbag over his head and poncho over his body, the GI giving a thumbs-up sign next to the dead body of a prisoner.

Mr. Gourevitch is at pains to convey the ambiguities of these images, suggesting that sometimes the photos give a more sinister impression of what happened than was actually the case. Toward the end of the book, he describes the importance of the photos with the phrase “ocular proof.” This phrase is drawn from “Othello,” in which a ruse is undertaken to give Othello false proof that his wife is having an affair. Yet the fact that some of the photos gave a more negative impression of what was happening does not gainsay the seriousness of the crimes committed at Abu Ghraib.

Those crimes were enormous. At one point in the narrative, Mr. Gourevitch pauses to remark that the reader must “crave some relief, some release, from the relentless, claustrophobic annihilation of the dungeon: a clear and cleansing note of sanity, an interlude of avenging justice or an eruption of decency, the entry of a hero.” There is, he reports, “no such solace or sanctuary in this story. Abu Ghraib was bedlam” and the military intelligence block “was its sick, racing heart.” He writes: “There was no excuse for it, and there was nothing to show for it either, no great source of useful intelligence, no ends to justify the means.”

Though there were no heroes, one GI, Joseph Darby, did begin turning evidence in to military authorities, and the Army did launch, and announce, its investigation well before the press got onto the story. The Army’s announcement was given little play in the papers when it was made in January 2004. The famous scoops that scandalized the world were brought in several months later, by the New Yorker and “60 Minutes,” and were about the Army’s investigation. In the end, nearly a dozen GIs were found, or pleaded, guilty to mistreating prisoners through sexual humiliation, beatings, and other forms of abuse, and a number of them were sentenced to significant prison terms. Yet none was an officer.

“It would be outrageous, of course,” Mr. Gourevitch writes, “if the overseers of America’s biggest [military intelligence] operation in Iraq didn’t know what was happening with their most valued prisoners. But the complicity, the blind eye and the cover-up, the buck passing and the butt covering, the self-deception and the cowardice, the indiscipline and the incompetence infected every link in the chain of command that ran from the MI block to the Pentagon and the White House — a military bureaucracy that had been politically cowed and corrupted from the top down by civilian masters who had no experience of combat.”

Writes Mr. Gourevitch: “Later, when the photographs from the MI block were made public, and America’s disgrace was the talk of the world, there would be no end of speculation as to whether a direct link could be found — a document or a trail of documents, some undeniable evidence — tying the scenes in these pictures directly to those top civilians, the president, the vice president, the secretary of defense. This supposedly missing link was spoken of as the ‘smoking gun.’ But it wasn’t missing; it was there right in front of us. Abu Ghraib was the smoking gun.”

One doesn’t have to accept all of Mr. Gourevitch’s logic to observe an abiding aspect of war. It is so enormous, the stakes are so high, its horrors and glories so great, that even large crimes can get lost in the passing of the storm — to await the judgment of historians. It is what happened in respect of My Lai, and it is what will happen in respect of the abuses that took place, in the early months of our current war, at Abu Ghraib. So it will be important to have volumes like that produced by Messrs. Gourevitch and Morris to remind us, and our children, of what can happen when commanders are lax and soldiers, having grown weak and scared or for darker reasons, turn criminal.