The controversy over a 12-foot-high concrete wall, topped with barbed wire coils, to divide Sunni and Shia neighborhoods of Baghdad is a depressing benchmark for America's liberated Iraq. But it also presents an opportunity for the US to disentangle itself from the past four years and step ahead with greater clarity.
The Adhamiya wall is one of many military ideas to come from the "surge," or Baghdad Security Plan that began in mid-February, aimed at stemming violence to give negotiation a chance.
It was to have stretched three miles to divide the middle-class Sunni suburb of Adhamiya from adjoining Shia communities in an area that has suffered some of the worst sectarian killing and bombings. The 400,000 people living inside Iraq's first walled Sunni enclave would need to show biometric identity cards at checkpoints every time they moved in and out.
But the project was condemned not only by the Adhamiya residents, but also across Iraq's political leadership -- from the Sunni-run Adhamiya District Council to the Imam of the suburb's Abu Hanifa mosque, Sheikh Samir al-Ubaidi, to Prime Minister Nouri Al-Maliki, leader of the Shia-dominated Iraqi government.
Iraq's warring factions saw a future of partition and didn't like it.
On each side of the wall are elements of US foreign policy that extend far beyond Iraq. The most violent insurgents operating from inside Adhamiya draw their inspiration from the brutally-achieved 9/11 goals of Osama Bin Laden's Al Qaeda. The militia-controlled Shia areas outside have direct support from the Islamic government in Tehran, also no ally of the US.
America's long war against Islamic extremism will only end once those forces are no longer perceived as threats. How power is balanced between Iraq's rival communities and the factions within them will determine how quickly peace will come to the country and, possibly, to the wider Middle East.
But this balance may not be determined for months, or even years. So for the US to remain constructively involved, American leaders must adopt a changed mindset.
First, they must rid themselves of the back-story of the invasion, its aftermath and the temptation to blame. Bloodletting between the Shia and Sunni communities probably would have happened whichever way Saddam Hussein was removed. He was too powerful and his institutions too biased, corrupt and inflexible to have survived smooth transition.
Second, the next stage must be about Iraq and not America, although with a presidential election coming up, this might be asking the impossible.
The Middle East moves at an untidy pace, and American deadlines, too often dictated by the electoral cycle, can jeopardize the complex and textured deal-making that could bring a first uneasy peace.
The October 1st deadline set by the Democrats to start troop withdrawal is based on a perception that US public opinion wants closure on Iraq, but ignores the truth that Iraq is now a key theater for Al-Qaeda-inspired operations. Bomb attacks that are still rare elsewhere in the world are daily occurrences here.
To learn from its post-9/11 mistakes, America must revert its focus completely to the Al Qaeda fight, forensically separating the group and its ideals from any other form of Islamic hostility.
Put against the history of Indo-China, the Shia forces could be compared to the Vietcong and North Vietnamese government, a functioning state with whom the US eventually did a deal. Whereas, Al Qaeda resembles Cambodia's genocidal Khmer Rouge, a group with unworkable ideas that was never capable of building a functioning society.
Since the "surge" began in February, Shia clerics have ordered their militia to keep a low profile, while the wing of the Sunni insurgency led by Al Qaeda has upped the stakes with a devastating series of bombings. That in itself suggests endgame deals could be made with the Shia militia while with Al Qaeda that would be unconscionable.