Jonathan Chait is a very smart guy. He is also very stubborn. He refuses to reasses his views of what was going on in Iraq in 2002-3 in light of new evidence. He simply asserts "Saddam Hussein apparently remained in total denial about U.S. intentions to depose him." What evidence is there to support that claim ? Chait concludes that Saddam Hussein must have been in denial, because his response to US ultimata was not to make concessions which satisfied Bush. Chait simply assumes that he could possibly have done this. Bush demanded that Saddam Hussein surrender WMD. Not having any WMD to surrender, Saddam Hussein could not concede, say uncle or give in to the demand.
Somehow Chait has managed to overlook the little detail that Saddam Hussein had complied with all UN resolutions at the time of the invasion.
Now it was pretty clear to me that Bush was determined to depose Saddam Hussein so that even if he had WMD and surrendered WMD, we would still have invaded. But if Saddam Hussein was in denial of that, he had company as Bush vehemently denied that too. I think that Saddam Hussein believed, correctly, that if he surrendered power he would be killed. It isn't as if he wasn't widely hated. So he may have thought he was damned if he did and damned if he didn't. that isn't necessarily denial or reality. That quite probably was the situation.
Chait is, as ususal, very charitable towards Chait. His actual position was that we had to invade, because if we didn't it was quite likely that they would develope nuclear weapons. Now he conceded that he couldn't read Saddam Hussein's mind. However, he could have read Muhammad El Baredei et al's report. He chose not to. He assumed that he understood nuclear weapons even though he clearly has no clue how hard they are to make. He didn't bother to try to ask any experts at the DOE about anything (they were all forbidden to talk to reporters which should have made it clear that the Bush administration was lying about all things Iraqi and nuclear).
Chait made gross errors due to his refusal to perform due diligence before making influential proclamations on issues about which he knew very little and understood less.
If his problem was an inability to guess what was going in the mind of a strange and evil person, then he wouldn't be so discredited. Therefore he concludes that was the problem in spite of the fact that anyone who knows anything can tell that his claim is self serving nonsense.
By the way, I think very highly of Chait and read him regularly. But, like most pundits (Kevin Drum not included) he will write any sort of nonsense if the alternative is to admit that he was wrong wrong wrong due to arrogance and laziness.