The British withdrawal from their base in the centre of Basra to the airport on the outskirts is being presented either as part of the plan or as a retreat.
The Ministry of Defence said in a statement: "The decision is an Iraqi-led initiative and is part of a Coalition-endorsed process..." That last phrase signals that the Americans approve.
Prime Minister Gordon Brown said that it was "pre-planned and organised".
However, a long-time critic Patrick Cockburn of the Independent newspaper summed up the four-year British occupation of the city (with the loss of 168 British lives) in this way: "In terms of establishing an orderly government in Basra and a decent life for its people the British failure has been absolute."
The 550 troops based at Saddam Hussein's old palace will join 5,000 others at the airport base. A further reduction to 5,000 overall is expected soon and more will probably leave when Basra province is handed over to the Iraqis in the autumn. Maybe 2,000 or so will remain.
After that, British troops will be in what is called an "overwatch" role, ready to intervene if asked to by the Iraqi authorities, continuing to train the Iraqi security forces and guarding the supply route from Kuwait.
The manner of the withdrawal said a lot about the way the British occupation had developed. It was done largely at night under curfew. If the Mehdi army, the Shia militia that has harassed and attacked the British, had not been on a six-month ceasefire, for wider reasons connected to Shia politics, the force might have come under fire.
If the British presence had been such a success, the style of its ending would have been different.
The British government's hopes that, in Basra, British troops in soft berets could steer the city to peace and prosperity were not realised. The helmets came back as the troops were attacked and Basra is left under the control of a mixture of militias and security forces, sometimes one and the same thing.
In the end, the British view was that enough had been done to stabilise Basra and that in the final analysis, no foreign force could control how Iraqis themselves decide how to run the place.
Britain never did quite manage to understand that while the Iraqis, especially the Shia, were pleased to see Saddam go, they were not pleased to see the British stay.
For the British public, the drip-dip of casualties in Basra was suffered without an objective that was clear.
For the army, a key factor is that the troops are badly needed in Afghanistan.
Relations with the Americans
As for the Americans, there is a now a disparity between their offensive tactics in and around Baghdad and the withdrawal to base by the British.
But military analysts point to the very different circumstances of the two armies, with the Americans fighting a major uprising. If the British troops had been similarly engaged, their withdrawal would indeed have been a major disagreement. As it is, it might just be an irritant.
The difficulties of the Iraq operation has led to a falling out of allies, with two British general criticising the US plan for the occupation of Iraq as "intellectually bankrupt" and "fatally flawed".
By 15 September, President Bush will have reported to Congress on the progress of the surge of US troops into Iraq. It is likely that he will point to successes and to say, with the agreement of the US commander General David Petraeus, that the surge will continue for the time being.