Even after he was convicted on five felony counts and two misdemeanors last year, Ritter remained, as he always has, self-righteous and inclined toward seeing conspiracies. “I’m not humiliated,” he told me recently, when I suggested he should be. “It’s nobody else’s business. And anybody who seeks to make it their business, they should be humiliated. They should be ashamed. They should be embarrassed. What I did or what I didn’t do is nobody’s business but my own and my wife’s. And the fact that this had been dragged out into the public eye the way it has speaks volumes about our society.”

Those who came to Ritter’s defense around Iraq always argued that he was a courageous and patriotic American, unjustly defamed by opponents, while his critics portrayed him as unreliable and attention-starved — an “unstable” character, as Richard Perle, one of the administration’s war planners, once described him. The confounding thing about a figure as self-defeating and polarizing as Scott Ritter is that, with enough time, supporters and critics alike can come to feel they’ve been proved right.

“I’ll tell you why it doesn’t matter,” Ritter was saying. This was in October, a few weeks before he was to be sentenced for his crimes. I had asked him whether he thought he deserved some public acknowledgment that his warnings about Iraq and its supposed W.M.D.’s were correct. “Because today everybody knows I was right. I was right about one of the most significant issues in modern American history. I was the only one who was right about one of the most significant issues in modern American history.

“And yet,” Ritter went on, “the common reaction seems to be: ‘Well, that was then, this is now. Yeah, he was right back then, but how does that impact us today, 10 years later?’ ” He shook his head in disbelief. Ritter is an uncommonly articulate man, and when he gets going, the indignation flows in fully formed paragraphs. “What is the relevance of being right 10 years ago? I don’t know — talk about all the dead Americans. It’s relevant to their families, I would think. Talk about the tens of thousands of wounded Americans and the hundreds of thousands of dead and wounded Iraqis.”

We were sitting in a dark booth at the Recovery Room, a sports bar across the street from the Albany Medical Center. Ritter’s Georgian-born wife, Marina, whom he met as a weapons inspector in Russia in 1989, no longer allows reporters into their home, so Ritter and I had settled in here for the afternoon. Ritter, who was wearing a sweatshirt the size of a small tent, is a densely packed 6-foot-4. Talking to him about his various intrigues and scrapes with authority, I found it almost impossible to keep in mind any kind of linear narrative. He claims that the American government suspected him of spying for Israel; that Norman Schwarzkopf, the gulf-war general, once had him arrested; that the F.B.I. hounded Marina for years because it suspected she was former K.G.B. You can’t help wondering how one man managed to attract so much institutional persecution.

Ritter’s opponents on Iraq still aren’t willing to grant that he knew something they didn’t. The way they see it, Ritter, whose position on W.M.D.’s swung significantly after he left the country in 1998, was like the stopped clock that finally managed to tell the correct time. “Oh, no, he wasn’t pres­cient, I can’t agree with that,” said Richard Butler, who was Ritter’s boss under the United Nations in Iraq. “When he was the ‘Alpha Dog’ inspector,” Butler said, referring to Ritter’s own description of his aggressive tactics, “then by God, there were more weapons there, and we had to go find them — a contention for which he had inadequate evidence. When he became a peacenik, then it was all complete B.S., start to finish, and there were no weapons of mass destruction. And that also was a contention for which he had inadequate evidence.”

History will record, though, that Ritter was right, while those who showed him nothing but contempt were flat wrong. While he wasn’t the only one saying that the war’s pretense was false or that its aftermath could be calamitous, Ritter was almost certainly the most determined dissenter and the one with the most on-the-ground intelligence. And if his views on Hussein’s regime careened from one extreme to the other, at least he demonstrated a capacity to evolve in his thinking — something few policy makers or commentators showed themselves able to do at the time. No doubt his very existence continues to discomfit those who insisted on Hussein’s lethality, and whose explanation for why they were wrong — that the intelligence was fabricated, essentially — has always been undercut by the fact that Ritter was never taken in.