FWIW: While I believe he could have been blackmailed, wouldn’t this mean that he was blackmailed into being right, not out of being right? His original position was that Saddam was a threat, then he felt he wasn’t. The threat was largely based on the belief that Saddam had WMD. Saddam didn’t (or at least 3/4 of a million troops and 6 years haven’t found any). So he actually changed to the correct position.