He would not have survived a background check for a job at Slim's Used Cars, and was viewed with deep suspicion by the CIA and the state department; but he was good enough as a source for the New York Times, the Washington Post and other news outlets, all of whom burned their reputations on Chalabi's pyre of lies.
http://www.guardian.co.uk/comment/story/0%2C3604%2C1227334%2C00.html

If spies wanted a trophy to show what happens when their craft is perfectly executed, it would be a story written by Judith Miller on the front page of the New York Times on a Sunday morning in September 2002. She wrote that an intercepted shipment of aluminum tubes, to be used for centrifuges, was evidence that Saddam was building a uranium gas separator to develop nuclear material.

The story had an enormous impact, one amplified when national security adviser Condoleezza Rice, secretary of state Colin Powell and vice-president Dick Cheney all did appearances on the Sunday-morning talk shows, citing the first-rate journalism of the liberal NYT. No single story did more to advance the neoconservative cause.

"I had no reason to believe what I reported was inaccurate," Miller told me. "I believed the intelligence I had. We tried really hard to get more information and we vetted information very, very carefully." A few months after the aluminum tubes story, a former CIA analyst explained to me how simple it had been to manipulate the correspondent and her newspaper.

"The White House had a perfect deal with Miller," he said. "Chalabi is providing the Bush people with the information they need to support their political objectives, and he is supplying the same material to Judy Miller. Chalabi tips her on something and then she goes to the White House, which has already heard the same thing from Chalabi, and she gets it corroborated. She also got the Pentagon to confirm things for her, which made sense, since they were working so closely with Chalabi. Too bad Judy didn't spend a little more time talking to those of us who had information that contradicted almost everything Chalabi said."