A lot of people know about how Scott Ritter forcefully made the argument that the Bush administration in fact did not have convincing evidence that Saddam Hussein had weapons of mass destruction prior to the invasion. Yes, weapons inspectors were withdrawn by the US in 1998 and Ritter admitted that it was possible he had developed weapons since then. But he also pointed out that the development of these weapons should still be detectable. We can't rule out that he has succeeded in developing these in an undetectable way. But we shouldn't leap from "He could possibly have developed weapons" to "He probably developed weapons."
But as war approached Ritter was able to draw firmer conclusions about the weapons programs. Inspectors were allowed back in. They were actually able to inspect the various sites that the CIA and US government had identified as locations where prohibited weapons were being manufactured. They turned up nothing. So there was a very brief period before the war where we really knew. Ritter forcefully tried to communicate that. Obviously to no avail. Watch a program below that offers some of his analysis prior to the war.
Ritter is now making the case regarding Iran. What he's saying is a less controversial now. We know they aren't making nuclear weapons. But those with truly thick skulls still want to pretend they are. They want to listen to the Krauthammers and the Kristols and O'Reillys and all the other pundits that were so colossally wrong before. They'd have zero credibility in a media dominated by pursuit of truth. In a media owned by entities in pursuit of short term profit maximization however they still are treated with respect.