SO FAR IN THE WAR of public opinion, most Americans side with Armstrong, putting little faith in the charges made by the likes of Ressiot and Walsh. In a USA Today online poll conducted after the L'Équipe story broke, 72 percent of the more than 38,000 respondents agreed with Armstrong's statement that he was the victim of a journalistic hit.

Whatever Walsh is, he's no Fleet Street hack. For nine years, he's written for The Sunday Times, a respected paper with a circulation of 1.3 million. He's won three British Press Awards—a prominent award in British newspaper journalism—for Sports Writer of the Year, most recently in 2004 for a story about the Irish jockey Kieran Fallon.

For Walsh, the stakes couldn't be higher in his looming legal battles with Armstrong. His legal expenses are being covered by the Times and La Martinière, and it's highly unlikely that he'll pay any damages should he lose the English or French cases. But if his defense fails, he'll no longer be David Walsh, award-winning sportswriter, but David Walsh, convicted libeler. "I think if I lost, a lot of people would decide I mustn't have got the story right," Walsh says. "The Sunday Times has been incredibly supportive of me, and I don't imagine that would change—I hope it wouldn't."

To the extent that most Americans even know who Walsh is, their impressions are formed mostly through Armstrong's vehement opinions. "I just hate the guy," he told writer Daniel Coyle in the 2005 book Lance Armstrong's War, adding that Walsh is a "fucking little troll."

For his part, Walsh declines to respond to Armstrong's bitter personal criticism in kind, and he displays no outward signs of animus toward the Tour champion. His cause, he says, is to root out corruption in cycling, not to destroy Armstrong.

According to Walsh, his pursuit of Armstrong evolved from his experience covering the high-stakes cat-and-mouse game between cheating athletes and anti-doping agencies beginning in the late eighties. After Irish swimmer Michelle Smith won three gold medals at the Atlanta Olympic Games, in 1996, Walsh wrote a Sunday Times column questioning her achievements. His argument, like the one later used in L.A. Confidentiel, was based largely on circumstantial evidence, and in Smith's case Walsh was vindicated. During the preceding decade, Walsh pointed out, Smith had never been a top competitor; her physique had grown more muscular in a brief period of time; and she was coached by her future husband, former discus thrower Erik de Bruin, a Dutchman who had served a ban from competition for elevated testosterone levels. Even though Smith had never tested positive, Walsh refused to believe she was clean.

"That she would become a woman who could win three gold medals was just bizarre," says Walsh.

In 1998, Smith did test positive: Evidence of androstenedione, a testosterone booster that supposedly helps increase lean muscle mass, was found in a urine sample, and, just as significant, she was busted for spiking the sample with alcohol. After being banned from competition for four years, she retired.

Walsh says he started reporting on cycling in 1980, mostly as an enthusiastic fan. Two years later, Irish rider Sean Kelly began his string of winning four green jerseys as one of the Tour's best sprinters of the eighties. Walsh was frustrated that Kelly's supreme athletic accomplishments were largely being ignored in Ireland. "People didn't understand cycling, and the journalists weren't bothering to go out and explain it," he says. "So I took Kelly on almost as part of my mission in life, to explain to people what a great athlete he was." In a 1994 book, Inside the Tour de France, Walsh included a sympathetic portrait of a young phenom from Texas named Lance Armstrong.

Then, in 1998, just before the Tour started with a historic visit to Ireland, Festina soigneur Willy Voet was stopped by French customs police on a country road near the France-Belgium border. Among other drugs in his car were 234 doses of EPO. Voet and team director Bruno Roussel admitted to running a doping program for the team. Star Festina riders Alex Zülle and Richard Virenque confessed to drug use and served eight- and nine-month suspensions, respectively. The magnitude of the bust led to a disastrous 1998 Tour with further police raids on teams during the race and sit-down strikes by the racers—a severe blow to cycling's credibility.

But the '98 Tour was also a watershed in the fight against doping. The scandal led to the creation of WADA and the beginning of standardized anti-doping rules followed by various countries, resulting in more sophisticated tests—the EPO urine test created in 2000 was first used in cycling at the 2001 Tour—and harsher penalties. The 1999 Tour, said race director Jean-Marie Leblanc at the time, would be a Tour of "renewal." Walsh says he went to see if that would prove true.