As British forces come to the end of their role in Iraq, what sort of country do they leave behind? Has the United States turned the tide in Baghdad? Does the fall in violence mean that the country is stabilising after more than four years of war? Or are we seeing only a temporary pause in the fighting?American commentators are generally making the same mistake that they have made since the invasion of Iraq was first contemplated five years ago. They look at Iraq in over-simple terms and exaggerate the extent to which the US is making the political weather and is in control of events there.
The US is the most powerful single force in Iraq but by no means the only one. The shape of Iraqi politics has changed over the past year, though for reasons that have little to do with "the surge" - the 30,000 US troop reinforcements - and much to do with the battle for supremacy between the Sunni and Shia Muslim communities.
The Sunni Arabs of Iraq turned against al Qa'ida partly because it tried to monopolise power but primarily because it brought their community close to catastrophe. The Sunni war against US occupation had gone surprisingly well for them since it began in 2003. It was a second war, the one against the Shia majority led by al-Qa'ida, which the Sunni were losing, with disastrous results for themselves. "The Sunni people now think they cannot fight two wars - against the occupation and the government - at the same time," a Sunni friend in Baghdad told me last week. "We must be more realistic and accept the occupation for the moment."
This is why much of the non-al-Qa'ida Sunni insurgency has effectively changed sides. An important reason why al-Qa'ida has lost ground so swiftly is a split within its own ranks. The US military - the State Department has been very much marginalised in decision-making in Baghdad - does not want to emphasise that many of the Sunni fighters now on the US payroll, who are misleadingly called "concerned citizens", until recently belonged to al Qa'ida and have the blood of a great many Iraqi civilians and American soldiers on their hands.
The Sunni Arabs, five million out of an Iraqi population of 27 million and the mainstay of Saddam Hussein's government, were the core of the resistance to the US occupation. But they have also been fighting a sectarian war to prevent the 16 million Shia and the five million Kurds holding power.
At first, the Shia were very patient in the face of atrocities. Vehicles, packed with explosives and driven by suicide bombers, were regularly detonated in the middle of crowded Shia market places or religious processions, killing and maiming hundreds of people. The bombers came from al-Qa'ida but the attacks were never wholeheartedly condemned by Sunni political leaders or other guerrilla groups. The bombings were also very short-sighted since the Iraqi Shia outnumber the Sunni three to one. Retaliation was restrained until a bomb destroyed the revered Shia al-Askari shrine in Samarra on 22 February, 2006.
The bombing led to a savage Shia onslaught on the Sunni, which became known in Iraq as "the battle for Baghdad". This struggle was won by the Shia. They were always the majority in the capital but, by the end of 2006, they controlled 75 per cent of the city. The Sunni fled or were pressed back into a few enclaves, mostly in west Baghdad.
In the wake of this defeat, there was less and less point in the Sunni trying expel the Americans when the Sunni community was itself being evicted by the Shia from large parts of Iraq. The Iraqi Sunni leaders had also miscalculated that an assault on their community by the Shia would provoke Arab Sunni states like Saudi Arabia and Egypt into giving them more support but this never materialised.
It was al-Qa'ida's slaughter of Shia civilians, whom it sees as heretics worthy of death, which brought disaster to the Sunni community. Al-Qa'ida also grossly overplayed its hand at the end of last year by setting up the Islamic State of Iraq, which tried to fasten its control on other insurgent groups and the Sunni community as a whole. Sunni garbage collectors were killed because they worked for the government and Sunni families in Baghdad were ordered to send one of their members to join al Qai'da. Bizarrely, even Osama bin Laden, who never had much influence over al Qa'ida in Iraq, was reduced to advising his acolytes against extremism.
Defeat in Baghdad and the extreme unpopularity of al Qa'ida gave the impulse for the formation of the 77,000-strong anti-al-Qa'ida Sunni militia, often under tribal leadership, which is armed and paid for by the US. But the creation of this force is a new stage in the war in Iraq rather than an end to the conflict.
Sunni enclaves in Baghdad are safer, but not districts where Sunni and Shia face each other. There are few mixed areas left. Many of the Sunni fighters say openly that they see the elimination of al Qai'ida as a preliminary to an attack on the Shia militias, notably the Mehdi Army of Muqtada al-Sadr, which triumphed last year.
The creation of a US-backed Sunni militia both strengthens and weakens the Iraqi government. It is strengthened in so far as the Sunni insurrection is less effective and weakened because it does not control this new force.
If the Sunni guerrillas were one source of violence in 2006 the other was the Mehdi Army, led by Muqtada al-Sadr, the Shia nationalist cleric. This has been stood down because he wants to purge it of elements he does not control, and wishes to avoid a military confrontation with his rivals within the Shia community if they are backed by the US army. But the Mehdi Army would certainly fight if the Shia community came under attack or the Americans pressured it too hard.
American politicians continually throw up their hands in disgust that Iraqis cannot reconcile or agree on how to share power. But equally destabilising is the presence of a large US army in Iraq and the uncertainty about what role the US will play in future. However much Iraqis may fight among themselves, a central political fact in Iraq remains the unpopularity of the US-led occupation outside Kurdistan. This has grown year by year since the fall of Saddam Hussein. A detailed opinion poll carried out by ABC News, BBC and NTV of Japan in August found that 57 per cent of Iraqis believe that attacks on US forces are acceptable.
Nothing is resolved in Iraq. Power is wholly fragmented. The Americans will discover, as the British learned to their cost in Basra, that they have few permanent allies in Iraq. It has become a land of warlords in which fragile ceasefires might last for months and might equally collapse tomorrow.
Middle East correspondent for the British newspaper The Independent, Patrick Cockburn was awarded the 2005 Martha Gellhorn prize for war reporting. His book on his years covering the war in Iraq, The Occupation: War and Resistance in Iraq (Verso) was a finalist for the National Book Critics Circle Award for non-fiction.
© 2007 The Independent