The Iraqis were routinely firing missiles at our pilots before the United States invaded. Every missile fired by the Iraqis was act of war and it would have been irresponsible for Bush not to give the go ahead to invade Iraq - particularly since our repeated failures to respond to acts of war by Al Qaeda had led to 9/11.
We should not have allowed the Iraqis to run their own country until they showed they were willing to do so in cooperation with one another.
The first Gulf War was a success because George H. W. Bush was able to get a truly international team together around a clear objective (free Kuwait) and then honored and respected the coalition by ending the war as soon as that goal was accomplished.
Every historian, military strategist, and political theorist with any brains told us that Iraq was a basket case. That without a very strong and vicious leader like Saddam keeping them in check, the citizens would soon be at each others throats. That is exactly what happened.
The international community didn't support the Iraq War because they were smart enough to know that it was going to ultimately fail. Especially since everyone knew that the only long term solution was a dictatorship as determined as Saddam's maybe without so much senseless murder and torture.
Because Bush knew that he wasn't getting any international support, and because Bush was unwilling to implement a military dictatorship, he guaranteed failure from the outset.
The neocons were way too optimistic about the prospects for a "free" Iraq. Either that or they were just whispering sweet nothings into Bush's ears so that their war profiteer buddies could collect their unjust rewards.