The 720-page report compiled by the Combat Studies Institute at Fort Leavenworth, Kansas, details the effects of having too few coalition troops on the ground when the reality after the fall of Baghdad was "severely out of line" with the anticipated conditions.

"We had the wrong assumptions, and therefore, we had the wrong plan to put into play," Gen. William Wallace, who commanded the Army's V Corps during the invasion, told the authors.

But some of the most critical decisions were made between May and August 2003, which some participants called a "window of opportunity that could have been exploited to produce the conditions for the quick creation of a new Iraq."

Army criticizes itself in Iraq invasion report