When the Coalition forces invaded Iraq, the justification was that Saddam had WMDs. From a moral standpoint, if the invasion of Iraq was justified because Iraq was believed to have WMDs, then attacks on the United States would also be justified-after all, everyone knows that we have WMDs.
When it turned out that Iraq did not have WMDs, the justification switched to terrorism. That turned out to be mistaken at the time, but is true now. Thanks to the invasion, Iraq is now a hotbed of terrorist activity. There is a great deal of irony in creating exactly the situation that was used to justify the war. This almost seems like picking a fight and then saying that it was justified because the other person started swinging back.
After the terrorism justification came the “Saddam is a bad man” line. It is true that he was a bad man. He employed secret police and used brutality and fear to rule the populace. Torture and imprisonment were regularly used by the state. Ironically, after the United States invaded, the torture and imprisonment continued. This time, however, it was Americans who were imprisoning and torturing people. In the United States, Bush continued to use fear and secret police tactics (domestic spying, etc.). So, the irony is that if we were justified in taking Saddam out for being a bad man, then if someone took out our government, they would be justified on the same moral grounds.
There is a terrible moral irony in the fact that the moral justifications for the Iraq war would also seem to morally justify attacks on the United States.