In an interview with Robert Draper, author of the new book, “Dead Certain,” Mr. Bush sounded as if he had been taken aback by the decision, or at least by the need to abandon the original plan to keep the army together.The president (via this book) ascribes responsibility for that decision exclusively to L. Paul Bremer, the then head of the Coalition Provisional Authority. Bremer, in the same Times article, says the president knew of and supported the disbandment policies.
“The policy had been to keep the army intact; didn’t happen,” Mr. Bush told the interviewer.
Incidentally, in the weeks preceding Donald Rumsfeld's resignation, Bush had referred to himself as "the decider." It's possible, though, that he only meant that he's the decider in regards to personnel decisions, not policy ones.
At any rate, here's how Thomas Ricks describes the decision to disband the Iraqi military in his book Fiasco (this comes from page 163 of the book's paperback edition):
[It] threw out of work more than a half a million people and alienated many more dependent on those lost incomes. Just as important, in a country riven by sectarian and ethnic fault lines- Sunni versus Shiite versus Kurd- and possessing few unifying institutions, [the order] had done away with two of the most important ones. Moreover, the moves undercut the fragile remnants of the police structure.In abolishing the military and intelligence services, then, the United States not only lost allies and labor for the rebuilding effort, they antagonized over 500,000 people with military and weapon-handling experience. They basically gave the insurgency 500,000 competent warriors.
According to the president, though, this is not what was supposed to happen. His policy, all along he says, was to keep the Iraqi military in tact. So how did he react when he heard that Bremer effectively overruled and reversed his (the president's) policy?