BBC World Affairs Editor, Baghdad
"This," a leading American supporter of President George W Bush wrote in a British newspaper back in February 2003, just before the invasion of Iraq, "is our imperial moment".
He went on to argue that the British had no right to criticise America for doing what they themselves had done so enthusiastically a century before.
But America's imperial moment did not last long. And now, seven years later, the US is criticised for just about everything that happens here.
Opinion is evenly divided between those who are glad to see the Americans go, and those who criticise them for leaving too soon and potentially laying Iraq open to fresh sectarian violence.
It is a pattern that every occupying power becomes used to. America, it seems, cannot do anything right - not even getting out.
Most of the arguments in favour of invading back in 2003 have come to nothing.
Many Iraqis welcomed the overthrow of Saddam Hussein - 50% regarded the invasion as a liberation, according to a BBC poll taken in 2004, while 50% regarded it as an occupation - but nowadays it is hard to find anyone who sees America as Iraq's friend and mentor.
Nor has the overthrow of Saddam Hussein led to a general domino effect towards democracy throughout the Middle East.
On the contrary, America's position in the Middle East has been visibly eroded.
Some of the things done by the American authorities in Iraq, based in the Green Zone in Baghdad, were sober, positive and practical.
Some have become a burden, for instance the constitution the Americans wished on Iraq, which makes it fiendishly hard to create a decent effective government.
And because the Green Zone administration was thrown together in a huge hurry back in 2002-03, overseen by former Defence Secretary Donald Rumsfeld - a man with no interest in nation-building - some of what was done involved grotesque levels of corruption and mismanagement.
Mr Rumsfeld was sent a careful, conscientious 900-page report by the state department containing detailed plans for the post-invasion period. He reportedly dumped it, unopened, straight into his waste-paper basket.
Iraqis, and some Americans, pile a good deal of the blame for what happened during this period on to Mr Rumsfeld's ally Paul Bremer, the temperamental pro-consul who often seemed unaware of what was going on right under his nose.
Former Vice-President Dick Cheney, when asked by the Saudi foreign minister why the US insisted on going ahead with the invasion, answered: "Because it's do-able."
But the problem began even higher up.
A respected Iraqi dissident, who later became vice-president, has described how shocked he was to find, a few weeks before the invasion, that President Bush seemed wholly unaware that Muslims in Iraq were divided between Shia and Sunni Islam.
American generals seemed to despair of finding a solution to the growing insurgency.
The US forces, contrary to all the basic rules of counter-insurgency, allowed the enemy to attack "Route Irish", the main road between Baghdad airport and the Green Zone, as and when it chose.
British soldiers, used to Northern Ireland, pointed out again and again that occasional nervous sorties in armoured vehicles were not the same as taking control of it.
Their American counterparts took no notice, and the situation grew worse.
It took an expert in counter-terrorism, Gen David Petraeus, to turn the situation around. Like most successful generals, he had luck on his side.
Gen Petraeus understood that insurgencies have a specific life-span, and he was fortunate enough to arrive in Baghdad at the time when the Iraqi insurgency was starting to wind down.
Sunni Muslims were increasingly sick of the violence that Sunni extremists were causing, and he encouraged the growth of Awakening Councils which enabled moderate Sunnis to rise up and deal with both Baathists and supporters of al-Qaeda.
The supply of people willing to become suicide bombers began to dwindle.
Gen Petraeus's tactics turned the tide. At the height of the violence something like 100 people were dying each day across the country from bombings and shootings.
Now the number killed in political violence has dropped to about 10 a day - unacceptable in a more peaceable society, but a great relief here.
Yet many Iraqis fear that with the Americans no longer here in force, and the Iraqi army and police still lacking sufficient training, the violent extremists on both the Sunni and the Shia sides could start fighting again.
Whatever happens here for the next decade, the Americans will get the blame - unless of course Iraq becomes peaceful and prosperous, in which case no-one will thank them.
That is the usual fate of an occupying force.
Vast numbers of people have died, the overwhelming majority of them Iraqi.
Unthinkably large amounts of money have been spent here, and yet Iraq has slipped far down the world's rich list.
Has the United States benefited? It is hard to see how.
As the British learned in the Boer War, and Russia learned by invading Afghanistan, great military powers run big risks by putting their strength to the test against weak-seeming opponents.
America seems to have shrunk as a direct result of its imperial adventure in Iraq.
It will have to work very hard to persuade the rest of the world that it is strong again.