Paul Bremer, America's former proconsul in Baghdad, today defended his reputation against comments from President George Bush that the official had acted on his own accord in committing one of the most calamitious mistakes of the Iraq war.

In a breach with the Administration he once served, Mr Bremer released two letters to the New York Times refuting Mr Bush's remarks in a new biography that the White House was not involved in the decision to dissolve the Iraqi army.

The disbanding of Saddam Hussein's military left hundreds of thousands of Iraqi soldiers stranded without jobs or income, and is widely recognised as one of the most disastrous measures undertaken by Mr Bremer during his year-long authority in Baghdad.

Mr Bremer, who has been blamed for many of the failures of the post-war occupation, apparently was unwilling to take it any more. He released two letters to the Times to prove his assertion that the White House and the Pentagon knew in advance of his plan to dismantle the military and that they approved.

Mr Bremer told the newspaper he sent a draft of the order to the Pentagon on May 9, 2003 and that it had been circulated widely to the Defence Secretary, Donald Rumsfeld, and other officials. "It was not a controversial decision."

In the first letter, from Mr Bremer to Mr Bush, dated May 22, 2003, Mr Bremer writes at length about Iraqis weeping tears of joy at their liberation by US troops, and the dissolution of Saddam Hussein's ruling Ba'ath Party.

"We must make it clear to everyone that we mean business: that Saddam and the Ba'athists are finished," he writes. He tells Mr Bush that the de-Baathification of the civil service was proving popular despite "some inefficiencies and griping".

He deals with the disbanding of the army in a single, obliquely worded sentence. "I will parallel this step with an even more robust measure dissolving Saddam's military and intelligence structures to emphasize that we mean business."

The breezy tone of Mr Bremer's letter is at odds with the sweeping implications of the decision to do away with one of Iraq's main institutions, and the strong opposition to the dissolution of the army from US military officials at the time.

Mr Bush responded the next day, in a brief reply sent from his ranch in Texas. Though it was such an instrumental step in the de-Baathification process, there is no direct reference to dissolving Saddam's army.

"Your leadership is apparent. You have quickly made a positive and significant impact. You have my full support and confidence. You also have the backing of our Administration that knows our work will take time," Mr Bush writes.

The publication of that exchange of letters between the White House and Washington's man in Baghdad sheds new light on the chaotic and somewhat incidental way in which Mr Bush dealt with events in Iraq - though his legacy as president will be almost entirely defined by the war.

Further revelations about the dysfunction in the Bush White House surfaced this week with the publication of a new biography, Dead Certain.

In his conversations with the author, Robert Draper, Mr Bush admitted that disbanding Saddam's military had been a major mistake. "The policy was to keep the army intact; didn't happen," he said.

He then suggested that he had been left out of the loop by Mr Bremer. "Yeah, I can't remember, I'm sure I said, 'This is the policy, what happened?'" Mr Bush is quoted as saying. He then told Draper to check with his national security adviser, Stephen Hadley.