But why didn't the truth get out of Iraq? That's because many senior Iraqi officials believed Saddam's deception. To contradict Saddam could get you killed, and that was no myth. When Saddam finally told his generals, three months before the U.S. invaded in 2003, that Iraq had no WMD, the generals were dismayed. They already knew their forces were in no condition to resist the Americans, and always believed that Saddam's WMD would give them something to work with.
But it got worse. After the 1991 war, Saddam's generals were afraid to tell him how superior the American forces were, and why. This was because Saddam tended to kill people who brought him bad news. So all that stuff from Saddam in the 1990s, about how Iraq had actually won the 1991, was what himself Saddam believed. After all, his generals told him so.
As a result of all this fear and deception, anyone outside Iraq, trying to find out what was happening, would gather all sorts of information indicating that Saddam still had WMD. Even Arab diplomats, who could schmooze with senior Iraqi officials, got the same story. Saddam especially wanted the Arab world to believe he had WMD, because that made him a hero in the Arab world. And so it came to pass that Saddam fooled everyone, including himself.
As thousands of captured Iraqi documents are translated, it becomes clearer why all the world's intelligence services were misled about Saddam's nonexistent weapons of mass destruction (WMD). A decade of UN WMD inspections did indeed destroy Saddam's WMD arsenal. But Saddam believed that he could not outright say he did not have any WMD. He believed that Iran would come after him if they believed Iraq did not have WMD. During the 1990s, the Iraqi armed forces gradually fell apart because of the UN sanctions. So Saddam needed something to make Iraq look stronger than it actually was.