Chalabi, Iraq's deputy prime minister, at December press conference in Baghdad © Mohammed Jalll / epa / epa / Corbis

Brooke's job at the Rendon Group had two prongs. First, he ran a PR campaign, complete with a traveling exhibition, detailing Saddam's atrocities. ("Doing anti-Saddam propaganda is as easy as falling off a log," he says.) Second, he helped organize Iraqi dissidents--some living in exile, others in Kurdistan--into a coalition known as the Iraqi National Congress. Working with Chalabi to plan the INC's kickoff gathering, Brooke was taken by the exile's "brilliant intellect" and command of politics.

Brooke stayed in London until 1994, when the Clinton administration shifted its focus away from supporting the Iraqi opposition. "I was sitting in a very nice office but essentially playing video games," he says. He returned to the U.S. and settled in Atlanta, but not for long: In 1996, Saddam Hussein's forces swept into Erbil, a Kurdish city under international protection. The Clinton administration failed to intervene, and the resulting massacre left hundreds dead. "People were calling from Iraq to Atlanta: 'They're coming over the hill. They're going to kill us,'" Brooke says. "I had 200 people I knew lined up and slaughtered. I was physically ill for a long time. And I felt it was my responsibility to fix it."

Temporarily leaving his family behind, Brooke relocated to Washington's Georgetown neighborhood, a short walk from the Presbyterian church one of his ancestors founded. ("We wanted to build a Southern church in Yankee land," he explains.) He moved into a townhouse owned by Chalabi, and the two men cohabitated "as bachelors." Without drawing a salary--"Money shows up when you need it," Brooke says--he set out to shift U.S. foreign policy.

Brooke and Chalabi found their allies among Washington's Republicans. Brooke, a lifelong Democrat, says he felt comfortable crossing party lines to seek assistance. "They're friends of mine," he says of the GOP leaders. "We all went to the same country club. We have a very similar background. We're American patriots." Brooke says he met daily with the drafters of the 1998 Iraq Liberation Act, which called explicitly for military assistance to opposition groups seeking Saddam's removal. The bill, introduced by Trent Lott, a Mississippi Republican, in the Senate and New York Republican Benjamin Gilman in the House, swept both chambers and was signed into law by President Clinton.

The bill's easy passage showed just how much traction Chalabi had gained in D.C. But the Iraqi's popularity didn't reach its apex until after President George W. Bush's 2000 election. In the new White House, Chalabi found an enthusiastic reception from neoconservatives: not just Cheney and Wolfowitz, but also Defense Secretary Donald Rumsfeld and Richard Perle, then chair of the Pentagon's Defense Policy Board. Chalabi was an attractive embodiment of Saddam's enemies. "He's very adept at public relations," says Azmat Hassan, a retired Pakistani diplomat who now teaches at Seton Hall University. "He speaks in the Western idiom. He dresses well. He had all the makings of an Iraqi who can impress a Western audience."

What's more, Chalabi offered a compelling message. "He told the neocons what they wanted to hear: Iraq would be a free-market democracy supporting the United States and Israel," says Toby Dodge, the Middle East scholar. "When someone says, 'Everything you want in Iraq, I can give to you,' it's like Christmas and Easter all rolled into one."

On September 11, 2001, Brooke heard the attack on the Pentagon from his Georgetown porch. He knew some of the victims, across the Potomac and in the World Trade Center. And he realized that the upcoming meeting of the Defense Policy Board, to which he was invited, would take on a new importance. A week later, he boarded a bus with the other meeting participants and traveled with police escort to the Pentagon, where the effort to recover bodies was still under way.

Once inside, he listened as the secretive board heard from Chalabi and neoconservative Princeton scholar Bernard Lewis. According to an account in Vanity Fair, Lewis spoke first, prodding the Pentagon to flex its military muscle in the Muslim world. Lewis also urged support for Iraq's democratic reformers--"such as my friend here, Dr. Chalabi." In turn, Chalabi told the board that Iraq possessed weapons of mass destructions (WMD) and possibly served as a breeding ground for terrorists.

Coming out of the meeting, Brooke saw a rare opportunity. "The environment was red hot," he says. Administration officials were eager for a confrontation with Iraq and looking for evidence of WMD to justify going to war. Seizing the moment, Brooke rustled up his contacts among Iraqi defectors. "I said, 'If you've got it, bring it on, because now's the time,' " he says.

The stories that emerged were harrowing. A civil engineer named Adnan Ihsan Saeed al-Haideri reported that Saddam had hidden secret weapons laboratories inside subterranean wells and private estates, and underneath a Baghdad hospital. An army defector named Sabah Khalifa Khodada Alami described a terrorist training camp near Salman Pak, south of Baghdad. In the end, though, many of the stories didn't check out. Saeed failed a lie-detector test, and none of the weapons he described ever emerged. U.S. officials now believe the Salman Pak camp was probably a counterterrorism facility. In 2003, the Defense Intelligence Agency concluded that most of the information provided by defectors recruited by the INC was practically worthless.

Hassan, the retired diplomat, believes that in his eagerness to overthrow Saddam Hussein, Chalabi knowingly channeled bad intelligence. "This evidence was doctored," he says. "It was cooked up. Ahmad Chalabi and the INC were behind this information. So surely they knew." But Brooke says it was not the INC's job to verify the quality of the reports. "A person comes to us and says, 'We have information,' " he says. "We verify that the person is who he says. We know what tribe he's from. We also verify the particulars of his CV: 'He was a lieutenant colonel in the 5th Brigade from '91 to '92.' That's it. There's no sense of doing anything else." Adds Brooke, "We haven't provided any false information to the United States--and no one can prove any different."