As we heard yesterday even US and UK top brass in Iraq got only a couple of days’ notice of the surge, and initially at least Washington and London had little idea how Knights would affect their joint strategy. (In the event it delayed UK troop withdrawal until mid-09, as soldiers were kept in Iraq to work alongside the Iraqi forces as military transition teams – the “embedded Mittings” Lyne joked about in Wednesday’s session.)

Although in retrospect the coalition says it viewed Knights as a comparative success – an empowered Maliki exercising his own national defence policy independent of occupation forces – the outcome was far from guaranteed.

Hundreds of Iraqi Army soldiers deserted and – avid inquiry followers may not be surprised to hear – many Iraqi police officers followed likewise, some at the orders of the militia itself. (There’s a decent analysis of the Knights campaign, and the difficulties it ran into, at this US military analysis think tank The Institute for the Study of War)

So it’s against that background that the inquiry takes evidence today from three witnesses; Lt-Gen Barney White Spunner (who was i/c multinational forces in the south east at the time) on the operation itself, and Nigel Haywood (consul general of Basra) and Keith MacKiggan (a DfID secondee who headed up provisional reconstruction).

Evidence from 10h00, live Tweets at twitter.com/iraqinquiryblog.

For the promised American pull-out from Iraq starts today. US forces start pulling out of urban areas in the country on what the Iraqi government has declared to be National Sovereignty Day.

This is not the end of the US-led occupation, merely the beginning of the end. 131,000 US forces remain and will do so until the cessation of combat operations in September 2010 and the eventual pull-out in 2011.

And the US and her allies leave amid an alarming upsurge of bomb attacks (200 dead in a week). Is it too fanciful to suggest that this horrifying adventure spells the last of such “wars of choice”?

Nonetheless, a military adventure which displaced some 4 million Iraqis, killed and wounded as many as a million (we shall never know the true figure), and reduced the country’s precious oil output to the point where, even today, it remains below that of Saddam’s final year in power, is coming to an end.

That adventure also shredded the reputation of Tony Blair at home and divided Europe as never before. This is before we even begin to estimate the financial costs of the war, which run into trillions of dollars.

So what were the Iraq war aims? To safeguard oil supplies? To remove Saddam? To instil a new democracy in the heart of the Middle East? To find and destroy weapons of mass destruction? To provide a bulwark against, and to reduce the power of, Iran?

Six new oilfield contracts are to be auctioned today, but production is still stagnant and the oil law is still stuck in the Iraqi parliament. Saddam has been replaced by an upsurge in radical religiously backed parties that threaten civil war at any turn.

Democracy has delivered a factional parliament and, in the prime minister, the firm hand that Iraq has grown used to. Water and power supplies remain inadequate. And Iran, despite recent events, is stronger than at any time since the Islamic revolution of 1979.

Perhaps Iraq enjoys a greater collective spirit of hope than at any recent time. But that hope has come expensively, and there is still a ways to go.

It is hard to imagine that history will smile on the two men, Bush and Blair, who decided to take the world in to this war – although it isn’t beyond the wit of Europe to reward one of them (who defied the majority of EU leaders on the war) with its presidency.