How did the US come to invade Iraq with no post-war plan for governing Iraq - and how much did Tony Blair know of the matter? John Ware reports in the first of two articles linked to a new TV series.
"Iraq will be better," declared Tony Blair five days after the fall of Saddam.
"Better for the region, better for the world, better, above all, for the Iraqi people."
That contrasts starkly with the several hundred thousand dead and injured Iraqis, four million refugees inside and outside Iraq, 4,141 coalition soldiers who have died and the cost to the UK of well in excess of £5bn.
The Blair-Bush vision was to turn Iraq into a stable nation
Yet it's now clear that Mr Blair knew before the invasion that America's planning for post-war recovery was woefully inadequate - and so was Britain's.
There was no properly worked-out strategy for the key longer term objective of transforming it into a stable, prosperous nation that the Blair-Bush vision held out.
'Tearing his hair out'
We know this because Lady [Sally] Morgan, Mr Blair's former political secretary, has said he was "tearing his hair out", and his former foreign affairs adviser Sir David Manning has said he was "very exercised about it".
NO PLAN, NO PEACE
2215 GMT, Sun 28 Oct
2245 GMT, Mon 29 Oct
The fact that Mr Blair feared the invasion aftermath might be heading for disaster is potentially more damaging to his reputation than his decision to put the full weight of his office behind the intelligence that Saddam had weapons of mass destruction. For that he had cover from the Secret Intelligence Service.
What, then, is his defence to the charge that he recklessly continued with the invasion?
His friends and advisers say his frustration stemmed from his inability to influence the Pentagon, under Donald Rumsfeld, on post-war planning.
Mr Rumsfeld took charge of post-war planning war in January 2003
The hawkish defence secretary had required his generals to give America a "lite" footprint - a small invasion force that could be rapidly withdrawn afterwards.
Does this defence stack up?
It suggests that Mr Blair's "hair tearing" did not begin until 20 January 2003 - just eight weeks before the invasion.
It was only then that Mr Rumsfeld was put in charge of post-war planning, with a presidential directive establishing a reconstruction unit in the Department of Defense.
Considering that the American General George C Marshall was given three-and-a-half years to plan the reconstruction of Germany after World War II, that's leaving things dangerously late.
So why wasn't Mr Blair "tearing his hair out" long before 20 January 2003?
Sir David Manning, recently retired ambassador to Washington, says neither he nor Blair "had any sense that the Department of Defence was going to take over the running of the country".
Until then, says Sir David, the president had assured them both that the State Department under the moderate Colin Powell would do this.
There had been "plans made and deployed by the State Department".
"It's hard to know what happened."
Yet the State Department's work was "never intended as a post-war plan", says Ryan Crocker, American ambassador to Iraq.
It was instead a series of expert study groups whose purpose was to engage Iraqi Americans in thinking about their country's future.
Far from believing the State Department would be in charge of reconstruction, the challenge to the British government throughout 2002 was to find out who would get the job.
'Black hole' in planning
A year before the invasion - on the eve of the first Blair-Bush Iraq summit in April 2002 - Sir Christopher Meyer, then British ambassador in Washington, says he urged Mr Blair to "above all start getting them to focus on what next if and when we drive Saddam from office".
Again, in early September, he warned Mr Blair that "planning for the aftermath is a blind spot. I remember thinking to myself: 'We're nowhere on this.'"
Sir Christopher Meyer warned Blair that planning was 'a blind spot'
Then a few weeks later Sir Christopher says he "upped the volume" to a warning that "there was a black hole in American planning for the aftermath".
If Mr Blair was tearing his hair out, it does not seem to have happened when it mattered - throughout 2002 - when there was still time to put together a practical plan.
I'm told that three months before the invasion, the Chief of the Defence Staff Admiral Boyce warned the Pentagon they would be "lucky to get six hours worth of flowers and roses" because liberation would soon turn to occupation.
There were no plans to fill the inevitable vacuum after regime change with a large scale development programme delivering quick wins to show Iraqis that things would be better.
So criminals and insurgents quickly poured into it and have been there ever since.
The charge Mr Blair may have to address in any future inquiry is that he never investigated the risks diligently.
There is little evidence that Whitehall performed any better than the Americans in putting together their own reconstruction plans for southern Iraq, for which they had responsibility.
As in Washington, a planning unit was not set up in London until eight weeks before the invasion.
Specialists like engineers to help with water, power and other basic services were very late in being lined up.
Sir Hilary Synnott, who later took charge of the Coalition Provisional Authority office in Basra, says: "I simply wasn't aware of any planning in relation to the civilian aspects of Basra.
"My first challenge was to find a computer."
And that was July - three months after the invasion.
In the rush to war, and in the blur of ideology, both capitals abandoned a principle that has been an iron law of warfare since Napoleon: Never take the first step without planning for what comes afterwards.
In a second article on Monday, John Ware reveals the extent of the mismanagement of the occupation of Iraq since the war.
"No Plan, No Peace" is on BBC One:
Part One: 2215GMT, Sun 28th Oct
Part Two: 2245GMT, Mon 29th Oct