Paul Bremer, who led the Coalition Provisional Authority in the wake of the invasion of Iraq, provided The New York Times with a series of letters he and Bush exchanged in May 2003 in which the military dismantling was discussed.
Bush wrote one after being told of Bremer's plan to disband the military that said: "You have quickly made a positive and significant impact. You have my full support and confidence."
However, in the newly published book, "Dead Certain," author Robert Draper quoted Bush as saying U.S. policy had been to keep the Iraqi army intact but that it "didn’t happen."
While numerous strategists have said the move was a mistake, Bremer told the Times he stood by it.
"The army had been the main instrument of repression under Saddam Hussein," he said. "I would go on to argue that it was the right decision. I’m not second-guessing it."