[BluffTHIS!]

No one has offered any conclusive proof that Bush lied, but rather that he assigned a higher probability to intel being correct than it should have been given. But why was that?

Let's say the intel properly analyzed would only lead one to conclude that there was only a 25% probability of Saddam having an ongoing chem weapons program or stockpile of useable weapons. But you have to add two other probabilities to that. The first is that Saddam would lie about same, and the second is that weapons inspections wouldn't be good enough to tell if he did. When you add those 3 probabilities together, it is very reasonable indeed to conclude a greater than 50/50 chance that Saddam has useable chem weapons, and to conlude as well that given his proclivity for using same on his own people, that such a combined probability was too great to go unanswered during a war against terrorism when rogue nations and bad actors like Saddam would be the biggest threats to supplying terrorists with such weapons.

And the true importance of the old and unusable chem weapons found (and one also has to look at how long they had been unusable to make any determination as well), is that Saddam did lie and the weapons inspectors did fail to find those old weapons. Thus the 2 other probablistic assumptions in the equation were valid and justified acting on intel that by itself wouldn't be credible enough.