It doesn't matter whether you think it was right or wrong to invade Iraq; the simple fact is that it's a done deal.
If the occupation were to end today, or even 6 months or a year from now, the country currently know as Iraq would likely dissolve into a human disaster not experienced in modern times. Saddam's government was far from perfect, but it at least brought a measure of stability to the general population. A whole generation of Iraqi citizens was raised knowing nothing about the "real world" other than the information (propaganda) provided to them by the government; North Koreans still face a similar situation.
While all humans are created equal, knowledge is one of the keys to a sustainable, civil society. The Iraqi people, who up until a year and half ago knew little about self-governance, are in a very vulnerable position right now. That's one reason foreigners, with agendas of their own, have flocked to Iraq. These foreigners, generally called "terrorists" here in the U.S. and mostly violent Islamic fundamentalists, are taking advantage of the Iraqi people. These new arrivals don't give a damn about the goodwill of the citizens themselves. Through Saddam, Iraqis have always been told that Americans are bad; the "terrorists" are backing up those long-held beliefs, thus creating the "insurgency" to further their own violent agendas.
The national community MUST unite at this point. The stated goal of the Administration is self-governance by the Iraqi people. Right now, the only way that can happen is with the major powers of the world working together to provide stability in the region. Iraq is nowhere near being able to successfully maintain its own governance.