By Gavin Hewitt
BBC News, Basra
British commanders are unsure about how history will judge their time in Iraq
At the Basra airbase, soldiers from the Queen's Royal Hussars take a hammer to the sleeve of a barrel of a Challenger tank.
It is the sound of winding down, of an army withdrawing. Within a short time British combat operations in Iraq will be over.
There is now an urgency to departure. The soldiers have the scent of homecoming, of the tarmac embrace, of the end to aching separations after several tours of duty.
The ordinary soldier rarely frets over legacy but the commanders do. There is an edginess to briefings. A sensitivity, as if the top brass is unsure of how their time will be judged.
Colonel Richard Stanford, the British officer who advised the head of the Iraqi forces, quoted an American general: "It is not about how it started, it is all about how it ends".
There is hope in Basra. The 14th Iraqi army is proving effective and competent.
But there is another legacy that is being debated - what the Iraqi invasion and operation has done to Britain.
It is a question about reputation, about Britain's standing in the world.
Sir Jeremy Greenstock was the diplomat who eloquently made the case for war. This is now his verdict.
"It wasn't legitimate in the eyes of most of the punters out there at the beginning," he told me, "and the effects of the operation through the invasion were not high enough to earn respect. So we carry some of that unpopularity."
They say British forces were overstretched and under-resourced and there was not the political will to support them in the fight against the militias
Lord Ashdown, a marine turned politician, had also supported the invasion.
He says that "the war and the failure to construct peace afterwards, which was grievous and didn't have to happen, that's done us damage overall".
Both men say that in the eyes of the world Britain is linked to the Americans.
"We will forever be associated with the Americans," said Sir Jeremy.
British military commanders are fiercely proud but defensive too. There are stories of unbelievable courage.
They also know, however, there are those in the Washington corridors who say Britain allowed the militias to effectively take over Basra and that the city was only freed by the Iraqi army.
They say British forces were overstretched and under-resourced and there was not the political will to support them in the fight against the militias.
"I've had senior military officers say to me that the Army is broken as a result of Iraq and Afghanistan", said Lord Ashdown.
Others believe that the legacy of Iraq has weakened Britain's will to use force globally without a clear mandate.
"I don't think we'll ever do that again," said Sir Jeremy, "without a clear UN resolution
and a much wider partnership."
Still some of these initial supporters of the war argue that it is too early for a final judgement. History shields its hand.
But even among those who backed the invasion there is a feeling that six years of combat has left Britain a little chastened, less certain of standing shoulder to shoulder with the United States in the conflicts of the future.