"We conclude that the Intelligence Community was dead wrong in almost all of its pre-war judgments about Iraq's weapons of mass destruction. This was a major intelligence failure. Its principal causes were the Intelligence Community's inability to collect good information about Iraq's WMD programs, serious errors in analyzing what information it could gather, and a failure to make clear just how much of its analysis was based on assumptions, rather than good evidence. On a matter of this importance, we simply cannot afford failures of this magnitude."
There have been plenty of other government reports on the failures. This is the first panel President Bush put together specifically to look at why American spy shops made such major errors about Iraq. Their conclusions that Saddam Hussein had WMDs and posed a threat to the US was a major justification for the March, 2003 invasion. (USA Today)