By Peter Biles
BBC world affairs correspondent
Lord Boyce called American lack of communication "dysfunctionalism"
The Iraq inquiry has produced another week of compelling evidence.
We are beginning to understand how and why Iraq ended up in such a parlous state after the 2003 invasion.
A number of witnesses have pointed a finger of blame at the United States for the chaos that ensued.
Sir David Manning, Tony Blair's former foreign policy adviser, set the tone with a withering attack on the Americans for their post-war planning.
"The assumption that the Americans would have a coherent plan which would be implemented after the war, obviously proved to be unfounded," he said.
On the setting-up of the Coalition Provisional Authority (CPA) in 2003, Sir David said: "The perception I had is that ambassador Paul Bremer arrived with pretty much the Americanised plenipotentiary power."
What followed was the controversial decision to disband the Iraqi army and carry out a purge of Saddam Hussein's Ba'ath Party.
The man in charge of the Foreign Office's overall Iraq effort in 2003, Sir Peter Ricketts, described how Mr Blair had visited Iraq in early June that year and concluded that the Office of Reconstruction and Humanitarian Assistance, set up by the US, was "a shambles".
The recurring theme at the inquiry has been the lack of communication in Washington before the war.
We have been given an impression of serious "disconnect" between the Pentagon, the State Department and the White House.
The former head of Britain's armed forces, Lord Boyce, called it "dysfunctionalism".
When US forces were advancing on Baghdad in March 2003, Lord Boyce had been extremely concerned about the "anorexic nature of the American contribution".
There were too few US troops on the ground, he said, and the Americans had made it clear they were in Iraq "to do the war fighting, not the peacekeeping".
At times, the witnesses have dominated the proceedings rather more than the gently spoken members of Sir John Chilcot's committee.
The smooth-tongued diplomats have rarely been troubled by any penetrating questions as the narrative of the Iraq war has begun to unfold in more detail.
For the most part, the committee, to use cricketing parlance, has been content to bowl gentle off-cutters, rather than unplayable yorkers.
Light relief has come from the transcription that is instantly available on TV monitors in the media room at London's Queen Elizabeth II Conference Centre.
The stenographers have produced some quirky errors in their valiant attempt to keep pace with the often quick-fire delivery of the evidence.
The name of the one-time Iraqi opposition figure, Ahmed Chalabi, flashed up on the screen as "Alcohol" Chalabi.
As lower ranking defence officials have been called to give evidence, plenty of jargon has been tossed around.
A former deputy chief of defence staff, Lt Gen Sir Anthony Pigott, did little to demystify the military-speak.
He talked about the "mil-mil relationship" between Britain and the US, issues that were for "US/UK eyes", the concept of "scoping" (exploring options) and the positioning of "blobs" (brigades).
Explaining why British forces were forced to abandon plans to move into Iraq from Turkey, Sir Anthony said "the price of the carpets had been too high".
Journalists attending the inquiry have been keen to know when key documents will be released into the public domain.
This may become a test of the inquiry's credibility as "independent and impartial".
Furthermore, it is understood that the evidence gathered from witnesses at these public hearings may constitute only about 10% of the volume of material gathered by the inquiry when it comes to publish its final report.
Next week sees some key witnesses including Air Chief Marshal Sir Brian Burridge, the commander of Operation Telic in 2002/3; Sir John Scarlett, the former chairman of the Joint Intelligence Committee; and Sir John Sawers, Tony Blair's former private secretary.