Clarification...
I meant "permitted by Saddam" to the extent that he had been permitting inspections, which is not much.
Your point is valid. Had Saddam done what South Africa did, and Libya seems to have done, he would still be in power and the entire thing would have unfolded in an entirely different way.
What he did do is engage in deception, concealment, and fraud. Whatever weapons he actually had, he did his damnedest to convince everyone he had something to hide. Well, he convinced the United States.
The analogy I usually use is the criminal holding a hostage with an object in his pocket, claiming it's a gun. If he gets shot by the SWAT team, and it turns out he was using his finger, whose fault is that?