Here is a smattering of some of the voices the Bush administration ignored (or worse) in the lead-up to the Iraq war. I'm sure more web surfing could turn up more like these. It gives one a sense of what an "Iraq Study Group" might have concluded in 2002-03 before we rushed to war.
My guess is that the first American tanks will be across [the Tigris] within one week of war--but what lies beyond? ...be assured, civil war will follow any American invasion of Iraq.
-Robert Fisk, November 10, 2002
The greatest risk for us in invading Iraq is probably not war itself, so much as: What happens after we win? The risks of an invasion setting off reactions from a hideous civil war in Iraq to toppling regimes all over the Middle East is very real.
-Molly Ivins, November 19, 2002
I assume we can defeat Hussein without great cost to our side (God forgive me if that is hubris). The problem is what happens after we win. The country is 20 percent Kurd, 20 percent Sunni and 60 percent Shiite. Can you say, "Horrible three-way civil war?"
-Molly Ivins, January 16, 2003
While the Iraqi people may initially respond to the deposing of Saddam Hussein and his clique with euphoria, many [U.S.] officers do not expect a quick or easy transition to anything resembling stability or democracy; indeed, some who have made a close study of the region anticipate "spheres of simultaneous civil conflict all over Iraq," as one put it, that will tax resources as well as US public opinion... According to former OSCE Bosnia chief Barry, while the right sees post-Saddam Iraq under US military governorship as akin to post-World War II Japan or Germany, it's more likely to resemble the former Yugoslavia...
-Jason Vest, February 13, 2003
Another document indicates that the UN is anticipating what it calls a "medium impact" scenario: "The military campaign encounters significant resistance, but ends after a more protracted period of two to three months. As a result of a large-scale ground offensive supported by aerial bombardments, there would be considerable destruction of critical infrastructure and sizable internal and external population movements." The report says there is a "major risk" of civil unrest in areas around Iraq that is "likely to result in high levels of casualties."
-Jason Scahill, February 13, 2003
Throwing Saddam Hussein and his Baath party out of power leads to a danger many of Iraq's neighbors have long warned about; a civil war. Iraq has always been an unstable country... Iraq's cast of potentially warring factions is a long one, and they are all waiting to present their grievances and demands to the occupation government and, following that, the next Iraqi government. No one has a solution for this coming conflict, but it's useful to know who is going to be fighting who, and why.
-James F. Dunnigan, April 4, 2003
(OK, so the last one is after the initial invasion, but still very early.) The price of Bush's arrogance and incompetence so far: 3,000 Americans killed; 45,000 American wounded; 50,000 Iraqis killed; 100,000+ Iraqis wounded...