I commend to your attention this highly readable summary of some of the key constituents of the catastrophe the U.S. inflicted on Iraq and the entire Middle East, by Fred Kaplan in Slate.
The decision to ban all members of the Baath party from government positions, and to disband the Iraqi army, left the country with no government, no army, and hundreds of thousands of unemployed men with guns. We all know what happened next.
What we did not know at the time was that the National Security Council principals had voted unanimously to vet government officials but leave most of them in place; and to disband Saddam's Republican Guard but otherwise to keep the army intact. Where did this order come from? Apparently it surprised the ostensible president of the United States at that time, who is today a beloved avuncular amateur painter and affable buffoon.
Kaplan writes:
This is the president of the United States, mind you. Kaplan concludes that Richard B. Cheney made the decision, and that Cheney had been duped by Ahmad Chalabi, an Iraqi exile who had been whispering in Cheney's ear urging the invasion, and who supplied fake intelligence sources about weapons of mass destruction. Cheney apparently actually believed that Chalabi could step in and form a government, and that he had a functioning militia that could be the core of a new Iraqi army. Neither was true. It was true, however, that Chalabi was an Iranian agent.
Why didn’t Bush rescind Bremer’s orders after reading about them in the newspaper? This is another mystery. When journalist Robert Draper posed the question, Bush replied, “The policy had been to keep the [Iraqi] army intact; didn’t happen.” Draper asked how he reacted to Bremer’s reversal. Bush replied, “Yeah, I can’t remember. I’m sure I said, ‘This is the policy, what happened?’ ”
So that's what happened. Kaplan concludes:
No one has been held accountable, no one has had to pay a price, except for the 100,000 or so Americans and Iraqis who died—and the untold numbers maimed or otherwise damaged—in the struggle to clean up the mess or simply got trapped in the crossfire.