“I wasn’t angry about what he said but disappointed that he would say that to me,” Taguba said. “I’d been in the Army thirty-two years by then, and it was the first time that I thought I was in the Mafia.”

THE INVESTIGATION

Taguba was given the job of investigating Abu Ghraib because of circumstance: the senior officer of the 800th Military Police Brigade, to which the soldiers in the photographs belonged, was a one-star general; Army regulations required that the head of the inquiry be senior to the commander of the unit being investigated, and Taguba, a two-star general, was available. “It was as simple as that,” he said. He vividly remembers his first thought upon seeing the photographs in late January of 2004: “Unbelievable! What were these people doing?” There was an immediate second thought: “This is big.”

Taguba decided to keep the photographs from most of the interrogators and researchers on his staff of twenty-three officers. “I didn’t want them to prejudge the soldiers they were investigating, so I put the photos in a safe,” he told me. “Anyone who wanted to see them had to have a need-to-know and go through me.” His decision to keep the staff in the background was also intended to insure that none of them suffered damage to his or her career because of involvement in the inquiry. “I knew it was going to be very sensitive because of the gravity of what was in front of us,” he said.

The team spent much of February, 2004, in Iraq. Taguba was overwhelmed by the scale of the wrongdoing. “These were people who were taken off the streets and put in jail—teen-agers and old men and women,” he said. “I kept on asking these questions of the officers I interviewed: ‘You knew what was going on. Why didn’t you do something to stop it?’ ”

Taguba’s assignment was limited to investigating the 800th M.P.s, but he quickly found signs of the involvement of military intelligence—both the 205th Military Intelligence Brigade, commanded by Colonel Thomas Pappas, which worked closely with the M.P.s, and what were called “other government agencies,” or O.G.A.s, a euphemism for the C.I.A. and special-operations units operating undercover in Iraq. Some of the earliest evidence involved Lieutenant Colonel Steven L. Jordan, whose name was mentioned in interviews with several M.P.s. For the first three weeks of the investigation, Jordan was nowhere to be found, despite repeated requests. When the investigators finally located him, he asked whether he needed to shave his beard before being interviewed—Taguba suspected that he had been dressing as a civilian. “When I asked him about his assignment, he says, ‘I’m a liaison officer for intelligence from Army headquarters in Iraq.’ ” But in the course of three or four interviews with Jordan, Taguba said, he began to suspect that the lieutenant colonel had been more intimately involved in the interrogation process—some of it brutal—for “high value” detainees.

“Jordan denied everything, and yet he had the authority to enter the prison’s ‘hard site’ ”—where the most important detainees were held—“carrying a carbine and an M9 pistol, which is against regulations,” Taguba said. Jordan had also led a squad of military policemen in a shoot-out inside the hard site with a detainee from Syria who had managed to obtain a gun. (A lawyer for Jordan disputed these allegations; in the shoot-out, he said, Jordan was “just another gun on the extraction team” and not the leader. He noted that Jordan was not a trained interrogator.)

Taguba said that Jordan’s “record reflected an extensive intelligence background.” He also had reason to believe that Jordan was not reporting through the chain of command. But Taguba’s narrowly focussed mission constrained the questions he could ask. “I suspected that somebody was giving them guidance, but I could not print that,” Taguba said.

“After all Jordan’s evasiveness and misleading responses, his rights were read to him,” Taguba went on. Jordan subsequently became the only officer facing trial on criminal charges in connection with Abu Ghraib and is scheduled to be court-martialled in late August. (Seven M.P.s were convicted of charges that included dereliction of duty, maltreatment, and assault; one defendant, Specialist Charles Graner, was sentenced to ten years in prison.) Last month, a military judge ruled that Jordan, who is still assigned to the Army’s Intelligence and Security Command, had not been appropriately advised of his rights during his interviews with Taguba, undermining the Army’s allegation that he lied during the Taguba inquiry. Six other charges remain, including failure to obey an order or regulation; cruelty and maltreatment; and false swearing and obstruction of justice. (His lawyer said, “The evidence clearly shows that he is innocent.”)

Taguba came to believe that Lieutenant General Sanchez, the Army commander in Iraq, and some of the generals assigned to the military headquarters in Baghdad had extensive knowledge of the abuse of prisoners in Abu Ghraib even before Joseph Darby came forward with the CD. Taguba was aware that in the fall of 2003—when much of the abuse took place—Sanchez routinely visited the prison, and witnessed at least one interrogation. According to Taguba, “Sanchez knew exactly what was going on.”

Taguba learned that in August, 2003, as the Sunni insurgency in Iraq was gaining force, the Pentagon had ordered Major General Geoffrey Miller, the commander at Guantánamo, to Iraq. His mission was to survey the prison system there and to find ways to improve the flow of intelligence. The core of Miller’s recommendations, as summarized in the Taguba report, was that the military police at Abu Ghraib should become part of the interrogation process: they should work closely with interrogators and intelligence officers in “setting the conditions for successful exploitation of the internees.”

Taguba concluded that Miller’s approach was not consistent with Army doctrine, which gave military police the overriding mission of making sure that the prisons were secure and orderly. His report cited testimony that interrogators and other intelligence personnel were encouraging the abuse of detainees. “Loosen this guy up for us,” one M.P. said he was told by a member of military intelligence. “Make sure he has a bad night.”

The M.P.s, Taguba said, “were being literally exploited by the military interrogators. My view is that those kids”—even the soldiers in the photographs—“were poorly led, not trained, and had not been given any standard operating procedures on how they should guard the detainees.”

Surprisingly, given Taguba’s findings, Miller was the officer chosen to restore order at Abu Ghraib. In April, 2004, a month after the report was filed, he was reassigned there as the deputy commander for detainee operations. “Miller called in the spring and asked to meet with me to discuss Abu Ghraib, but I waited for him and we never did meet,” Taguba recounted. Miller later told Taguba that he’d been ordered to Washington to meet with Rumsfeld before travelling to Iraq, but he never attempted to reschedule the meeting.

If they had spoken, Taguba said, he would have reminded Miller that at Abu Ghraib, unlike at Guantánamo, very few prisoners were affiliated with any terrorist group. Taguba had seen classified documents revealing that there were only “one or two” suspected Al Qaeda prisoners at Abu Ghraib. Most of the detainees had nothing to do with the insurgency. A few of them were common criminals.

Taguba had known Miller for years. “We served together in Korea and in the Pentagon, and his wife and mine used to go shopping together,” Taguba said. But, after his report became public, “Miller didn’t talk to me. He didn’t say a word when I passed him in the hallway.”

Despite the subsequent public furor over Abu Ghraib, neither the House nor the Senate Armed Services Committee hearings led to a serious effort to determine whether the scandal was a result of a high-level interrogation policy that encouraged abuse. At the House Committee hearing on May 7, 2004, a freshman Democratic congressman, Kendrick Meek, of Florida, asked Rumsfeld if it was time for him to resign. Rumsfeld replied, “I would resign in a minute if I thought that I couldn’t be effective. . . . I have to wrestle with that.” But, he added, “I’m certainly not going to resign because some people are trying to make a political issue out of it.” (Rumsfeld stayed in office for the next two and a half years, until the day after the 2006 congressional elections.) When I spoke to Meek recently, he said, “There was no way Rumsfeld didn’t know what was going on. He’s a guy who wants to know everything, and what he was giving us was hard to believe.”

Later that month, Rumsfeld appeared before a closed hearing of the House Defense Appropriations Subcommittee, which votes on the funds for all secret operations in the military. Representative David Obey, of Wisconsin, the senior Democrat at the hearing, told me that he had been angry when a fellow subcommittee member “made the comment that ‘Abu Ghraib was the price of defending democracy.’ I said that wasn’t the way I saw it, and that I didn’t want to see some corporal made into a scapegoat. This could not have happened without people in the upper echelon of the Administration giving signals. I just didn’t see how this was not systemic.”

Obey asked Rumsfeld a series of pointed questions. Taguba attended the closed hearing with Rumsfeld and recalled him bristling at Obey’s inquiries. “I don’t know what happened!” Rumsfeld told Obey. “Maybe you want to ask General Taguba.”

Taguba got a chance to answer questions on May 11th, when he was summoned to appear before the Senate Armed Services Committee. Under-Secretary Stephen Cambone sat beside him. (Cambone was Rumsfeld’s point man on interrogation policy.) Cambone, too, told the committee that he hadn’t known about the specific abuses at Abu Ghraib until he saw Taguba’s report, “when I was exposed to some of those photographs.”

Carl Levin, Democrat of Michigan, tried to focus on whether Abu Ghraib was the consequence of a larger detainee policy. “These acts of abuse were not the spontaneous actions of lower-ranking enlisted personnel,” Levin said. “These attempts to extract information from prisoners by abusive and degrading methods were clearly planned and suggested by others.” The senators repeatedly asked about General Miller’s trip to Iraq in 2003. Did the “Gitmo-izing” of Abu Ghraib—especially the model of using the M.P.s in “setting the conditions” for interrogations—lead to the abuses?

Cambone confirmed that Miller had been sent to Iraq with his approval, but insisted that the senators were “misreading General Miller’s intent.” Questioned on that point by Senator Jack Reed, Democrat of Rhode Island, Cambone said, “I don’t know that I was being told, and I don’t know that General Miller said that there should be that kind of activity that you are ascribing to his recommendation.”

Reed then asked Taguba, “Was it clear from your reading of the [Miller] report that one of the major recommendations was to use guards to condition these prisoners?” Taguba replied, “Yes, sir. That was recommended on the report.”

At another point, after Taguba confirmed that military intelligence had taken control of the M.P.s following Miller’s visit, Levin questioned Cambone:

LEVIN: Do you disagree with what the general just said? CAMBONE: Yes, sir. LEVIN: Pardon? CAMBONE: I do.

Taguba, looking back on his testimony, said, “That’s the reason I wasn’t in their camp—because I kept on contradicting them. I wasn’t about to lie to the committee. I knew I was already in a losing proposition. If I lie, I lose. And, if I tell the truth, I lose.”

Taguba had been scheduled to rotate to the Third Army’s headquarters, at Fort McPherson, Georgia, in June of 2004. He was instead ordered back to the Pentagon, to work in the office of the Assistant Secretary of Defense for Reserve Affairs. “It was a lateral assignment,” Taguba said, with a smile and a shrug. “I didn’t quibble. If you’re going to do that to me, well, O.K. We all serve at the pleasure of the President.” A retired four-star Army general later told Taguba that he had been sent to the job in the Pentagon so that he could “be watched.” Taguba realized that his career was at a dead end.

Later in 2004, Taguba encountered Rumsfeld and one of his senior press aides, Lawrence Di Rita, in the Pentagon Athletic Center. Taguba was getting dressed after a workout. “I was tying my shoes,” Taguba recalled. “I looked up, and there they were.” Rumsfeld, who was putting his clothes into a locker, recognized Taguba and said, “Hello, General.” Di Rita, who was standing beside Rumsfeld, said sarcastically, “See what you started, General? See what you started?”

Di Rita, who is now an official with Bank of America, recalled running into Taguba in the locker room but not his words. “Sounds like my brand of humor,” he said, in an e-mail. “A comment like that would have been in an attempt to lighten the mood for General Taguba.” (Di Rita added that Taguba had “my personal respect and admiration” and that of Rumsfeld. “He did a terrific job under difficult circumstances.”) However, Taguba was troubled by the encounter, and later told a colleague, “I’m now the problem.”

DENIABILITY

A dozen government investigations have been conducted into Abu Ghraib and detainee abuse. A few of them picked up on matters raised by Taguba’s report, but none followed through on the question of ultimate responsibility. Military investigators were precluded from looking into the role of Rumsfeld and other civilian leaders in the Pentagon; the result was that none found any high-level intelligence involvement in the abuse.

An independent panel headed by James R. Schlesinger, a former Secretary of Defense, did conclude that there was “institutional and personal responsibility at higher levels” for Abu Ghraib, but cleared Rumsfeld of any direct responsibility. In an August, 2004, report, the Schlesinger panel endorsed Rumsfeld’s complaints, citing “the reluctance to move bad news up the chain of command” as the most important factor in Washington’s failure to understand the significance of Abu Ghraib. “Given the magnitude of this problem, the Secretary of Defense and other senior DoD officials need a more effective information pipeline to inform them of high-profile incidents,” the report said. Schlesinger and his colleagues apparently were unaware of the early e-mail messages that had informed the Pentagon of Abu Ghraib.

The official inquiries consistently provided the public with less information about abuses than outside studies conducted by human-rights groups. In one case, in November, 2004, an Army investigation, by Brigadier General Richard Formica, into the treatment of detainees at Camp Nama, a Special Forces detention center at Baghdad International Airport, concluded that detainees who reported being sodomized or beaten were seeking sympathy and better treatment, and thus were not credible. For example, Army doctors had initially noted that a complaining detainee’s wounds were “consistent with the history [of abuse] he provided. . . . The doctor did find scars on his wrists and noted what he believed to be an anal fissure.” Formica had the detainee reëxamined two days later, by another doctor, who found “no fissure, and no scarring. . . . As a result, I did not find medical evidence of the sodomy.” In the case of a detainee who died in custody, Formica noted that there had been bruising to the “shoulders, chest, hip, and knees” but added, “It is not unusual for detainees to have minor bruising, cuts and scrapes.” In July, 2006, however, Human Rights Watch issued a fifty-three-page report on the “serious mistreatment” of detainees at Camp Nama and two other sites, largely based on witness accounts from Special Forces interrogators and others who served there.

Formica, asked to comment, wrote in an e-mail, “I conducted a thorough investigation . . . and stand by my report.” He said that “several issues” he discovered “were corrected.” His assignment, Formica noted, was to investigate a unit, and not to conduct “a systematic analysis of Special Operations activities.”

The Army also protected General Miller. Since 2002, F.B.I. agents at Guantánamo had been telling their superiors that their military counterparts were abusing detainees. The F.B.I. complaints were ignored until after Abu Ghraib. When an investigation was opened, in December, 2004, General Craddock, Rumsfeld’s former military aide, was in charge of the Army’s Southern Command, with jurisdiction over Guantánamo—he had been promoted a few months after Taguba’s visit to Rumsfeld’s office. Craddock appointed Air Force Lieutenant General Randall M. Schmidt, a straight-talking fighter pilot, to investigate the charges, which included alleged abuses during Miller’s tenure.

“I followed the bread-crumb trail,” Schmidt, who retired last year, told me. “I found some things that didn’t seem right. For lack of a camera, you could have seen in Guantánamo what was seen at Abu Ghraib.”

Schmidt found that Miller, with the encouragement of Rumsfeld, had focussed great attention on the interrogation of Mohammed al-Qahtani, a Saudi who was believed to be the so-called “twentieth hijacker.” Qahtani was interrogated “for twenty hours a day for at least fifty-four days,” Schmidt told investigators from the Army Inspector General’s office, who were reviewing his findings. “I mean, here’s this guy manacled, chained down, dogs brought in, put in his face, told to growl, show teeth, and that kind of stuff. And you can imagine the fear.”

At Guantánamo, Schmidt told the investigators, Miller “was responsible for the conduct of interrogations that I found to be abusive and degrading. The intent of those might have been to be abusive and degrading to get the information they needed. . . . Did the means justify the ends? That’s fine. . . . He was responsible.”

Schmidt formally recommended that Miller be “held accountable” and “admonished.” Craddock rejected this recommendation and absolved Miller of any responsibility for the mistreatment of the prisoners. The Inspector General inquiry endorsed Craddock’s action. “I was open with them,” Schmidt told me, referring to the I.G. investigators. “I told them, ‘I’ll do anything to help you get the truth.’ ” But when he read their final report, he said, “I didn’t recognize the five hours of interviews with me.”

Schmidt learned of Craddock’s reversal the day before they were to meet with Rumsfeld, in July, 2005. Rumsfeld was in frequent contact with Miller about the progress of Qahtani’s interrogation, and personally approved the most severe interrogation tactics. (“This wasn’t just daily business, when the Secretary of Defense is personally involved,” Schmidt told the Army investigators.) Nonetheless, Schmidt was impressed by Rumsfeld’s demonstrative surprise, dismay, and concern upon being told of the abuse. “He was going, ‘My God! Did I authorize putting a bra and underwear on this guy’s head and telling him all his buddies knew he was a homosexual?’ ”