Containment was a failure. Iraq has violated how many UN sanctions over the last 12 years? I believe the desire to go after Saddam would have happened as much as 8 years earlier if we didn't have a change in US policy (tried to say that diplomatically so as not to offend anyone). Christopher and later Albright IMO failed miserably in diplomatic relations with Iraq. Because of 9/11, I believe that Bush has the ability to demonstrate to America the consequences of letting a mad man remain in power - in a language they can understand.
Had 9/11 not happened, the case for going after Iraq would have been harder (but I believe that Bush would have still made the argument just like he did with North Korea) - not saying that Iraq was responsible, but rather American always felt that it was immune to attack from terrorists, now they know better.
If I read you right, your biggest beef is that Bush is using the 9/11 attacks as a way to go after potentially serious threats to the US when those who threaten were not directly responsible for the attack. I do not believe that Bush is making the connection of 9/11 with Iraq. I believe he is trying hard not to do so in order to be able to go after other countries who support terrorism after Iraq.