US spent trillions and left Iraq in violent pieces
As Iraq's prime minister visits Washington, BBC North America bureaux chief Paul Danahar, who was based in Baghdad during the US-led invasion, says the country America left behind is broken, and Middle Eastern strong men are flexing their muscles.
Only people with no long-term vested interest in the well-being of the subjects of a state could have conjured up Iraq.
Neither the country nor the political power structures within it would have naturally come about without the intervention of foreigners.
The Arab nationalism of Saddam Hussein's Baathism was a reaction to the selfish audacity of colonial rule.
The above is also broadly true in Syria. Neither country now necessarily has a future within its present borders.Sectarian strife
End Quote Donald Rumsfeld 2003
If you think we're going to spend a billion dollars of our money over there, you are sadly mistaken”
But it is clear that their people's futures, after the revolts of the Arab Spring, are increasingly intertwined.
Iraq's first colonial experience was at the hands of the British. Its second was at the hands of the US.
Even if recreating that experience was never America's intention, that's how the occupation was felt.
Both powers built sectarianism into the politics of Iraq - the British in overseeing the creation of the country and the Americans in the creation of the political structures they left behind.
Sectarian tensions in both Syria and Iraq are tearing at the fabric of already fragile societies.
The violence of the civil war in Syria has impacted on Iraq, which has impacted on Syria and the cycle goes on.
No-one knows how to stop it.
More importantly no-one wants to stop it, if that means getting involved themselves. Those that could make a difference have tried something similar in the past. They failed, and it cost them dear.
"My friend, if you think we're going to spend a billion dollars of our money over there, you are sadly mistaken."
The "over there" was Iraq. The man convinced, just weeks before the 2003 US-led invasion, that Iraq was not going to be a drain on American finances, was then-Defence Secretary Donald Rumsfeld.Corruption endemic
Ten years on, a study by Brown University concluded that the war cost the United States $2.2 trillion (£1.4 trillion).
Despite the blood and treasure America spent in Iraq it now has very little influence there, and Iraq is in almost as much of a mess now as it was at the height of the civil war that raged through most of the country.
How the US and UK baked sectarian strife into the Iraqi state
Like many colonial powers, in the early 20th Century the British brought in or co-opted people from the minority community, in Iraq's case Sunni Muslims, to run the institutions of state on their behalf.
The following century the Americans again allocated seats at the top table based on faith.
This time the majority Shia were put in the driving seat.
When Saddam was overthrown the Sunnis went from the top to the bottom of the heap. Since the US left, there's been little attempt to correct that.
"We sectarianised the country in a way that it had not been before," former US diplomat in Iraq and Yemen Barbara Bodine told me.
"You could be the best Sunni in the whole world, but... your chances of actually moving into a position of real power was very much circumscribed."
Iraq is broken. It's broken because it was never fixed.
The US got into Iraq badly and from an Iraqi point of view they got out equally as badly. Getting out, though, was the right thing to do because by December 2011 the US had more than overstayed its welcome.
But while there is much that can be blamed on the US there is also just as much blame for the Iraqi politicians left in charge. They have proved themselves to be thoroughly incapable of building democratic, accountable institutions. Corruption is endemic.
And if that wasn't bad enough this year has seen a huge increase in sectarian violence, much of it due to a campaign of bombings by al-Qaeda in Iraq. The United Nations estimates that more than 5,000 civilians have died this year alone.
This week the danger of a rapid descent in Iraq towards another sectarian civil war was highlighted by the man who tried to stop the last one.US didn't win
America's most famous soldier of modern times, Gen David Petraeus, wrote an opinion piece in Foreign Policy urging the country's leaders to act before it is too late.
The title of the piece was How we won in Iraq. I doubt Gen Petraeus chose that title because the US did not win in Iraq.
The "surge" of US troops to try to smother the violence was a success because it created the environment that allowed the Americans to leave. It didn't solve any of the underlying problems in the country.
And so in response to this recent upswing in violence, the Iraqi Prime Minister Nouri al-Maliki has come to Washington to ask for an increase in military aid, which he says he needs to fight the extremists.
The problem is that many Iraqis see him as part of the problem - not part of the solution.
A group of US senators, including John McCain, this week accused Mr al-Maliki, who draws much of his support from the country's Shia community, of "too often pursuing a sectarian and authoritarian agenda", which is pushing Sunnis "into the arms of al-Qaeda in Iraq".
Many see echoes of Saddam's rule emerging in that of Mr al-Maliki.
Iraq is why this American president has done everything he can to avoid getting involved in the Syrian conflict.
And Iraq is why most Americans agree with him on this issue.
The American people are exhausted by the emotional, physical and financial burdens placed on them by the war they fought in Iraq and the ongoing one in Afghanistan.Dithering Obama?
It's clear from listening to the debate here that the American people are convinced that doing anything militarily in the Middle East is the first step down a slippery slope that will inevitably lead to their young men and women fighting another war in another ungrateful country.
President Barack Obama's critics have accused him of over-learning the lessons of Iraq, which they believe has led to a dithering, policy-less approach over Syria.
That is unfair because there has been a policy. Post-Iraq, that policy has been "we are not getting involved", and under this president that is unlikely to change.
So Mr al-Maliki might get some new weapons from his meeting with Mr Obama.
And he will no doubt be told in private he needs to rule for all his people - not just those who share his faith or point of view.
He'll probably smile and agree and then ignore the advice while gladly accepting whatever aid he might get.
The world knows America has lost its appetite for foreign adventures. That is understood most keenly in the Middle East.
The credible threat of "or else" has all but disappeared from US foreign policy.
If the new 'strong men' emerging from the post-Arab Spring era, such as Mr al-Maliki and Egypt's General Abdel Fattah al-Sisi, have a certain spring in their step these days, it's because now is not a bad time to have authoritarian tendencies.
These men know there's nobody around at the moment who really wants to check them.
Paul Danahar was the BBC's Middle East bureau chief between 2010-13.