Comment: The greatest danger provoked by the US occupation of Iraq, writes Lara Marlowe, is not a worldwide Islamic empire but a sectarian war between Shia and Sunni which will resemble the bloody Protestant-Catholic strife of early modern Europe.
To justify his spurious claim of a link between the atrocities of September 11th and the invasion of Iraq, President Bush has in recent speeches portrayed the insurgency as an attempt "to establish a radical Islamic empire that spans from Spain to Indonesia".
But the Iraq war is not a titanic struggle encompassing the Muslim world. By the admission of Maj Gen Douglas Lute, the director of operations at Central Command, 90 per cent of what the US calls "the enemy" in Iraq is domestic.
The greatest danger created by the US occupation of Iraq is not the "radical Islamic empire" evoked by Mr Bush, but that of a conflagration between Sunni and Shia Muslims, the like of which has not been seen since Protestants and Catholics began fighting each other in the 16th century.
The outlines of a larger Sunni-Shia conflict are already drawn. Iraqi Sunnis increasingly refer to all Shias as "Iranians". Although Iran professes its desire to stay out of a conflict between Iraqis, the presence of 70 million Shia Iranians on Iraq's eastern border stacks the odds in favour of the 15.6 million (of 26 million) Iraqis. Nor can Iran remain indifferent to the fate of Shia Muslims in Saudi Arabia's eastern oil-producing province and Shia communities in Kuwait and Bahrain.
Public opinion across the predominately Sunni Arab world has sided with Iraq's Sunni minority. When Arab League secretary general Amr Moussa finally travelled to Baghdad last week, 2½ years after the invasion, his initiative was widely viewed as intervention on behalf of the Sunnis. Iraq has become so polarised that the Arab League, which might have played a constructive role, is now unacceptable to the 80 per cent of Iraqis who are Shia and non-Arab Kurds.
A frequently heard argument for continuing the US-led occupation is preventing a civil war - but there is already a civil war in Iraq, provoked by the US when it invaded the country. Thousands of Shia civilians have been slaughtered in bombings that targeted Shia shrines, mosques and marketplaces.
Now Shia militias - mainly the Badr Brigades, acting under cover of the interior minister - are arresting, torturing and killing Sunni men. As in Beirut in the 1970s or Yugoslavia in the late 1980s and early 1990s, the Iraqi population are relocating into segregated enclaves.
The Shia province of Diwaniya has banned the Sunni television station al-Sharqiya, claiming it spreads hatred of Shia.
Sunnis accuse the US-financed government channel al-Iraqiya of portraying all Sunnis as terrorists, notably in the reality television programme Terrorists in the Hands of Justice, in which Sunni suspects confess to plotting attacks on the Shia.
Like the Lebanese and Yugoslavs before them, Iraqis have become attuned to nuances of dress and language that identify them as Sunni or Shia. A young Sunni with friends in "the resistance" came to talk to me in the coffee shop of my hotel.
The Shia waiters eyed him uneasily. If he took me to the Sunni area of Aadamiya, he said, I must "dress like Sunni women, not Shia." After he left, the hotel security chief wanted to know who my "friend" was and where he lived.
To some extent, the violence is also the result of a class war sparked by the invasion. The Sunni and Shia bourgeoisie are appalled at the rise of the sherugi - the poor, uneducated Shias from the south and Sadr City who form the core of Sheikh Moqtada al-Sadr's Mehdi army militia.
There are several broken record versions of the war in Iraq.
The US version, which I heard from a military technician from Texas, goes like this: "We have to finish our mission. We Americans like coming to the rescue. These people need our help. It bothers me that we have to do their fighting for them, but they don't know how to fight. They asked us to overthrow Saddam, and now they don't want us."
The Sunni hard disc, which is shared by a surprising number of Shias, particularly from al-Sadr's movement, goes like this: "The CIA, Mossad and MI6 are responsible for the bombings that kill Iraqi civilians, because they want to create a civil war so they have an excuse to stay in Iraq and keep stealing our petrol."
The discourse that is least unfavourable to the Americans is heard from educated Shia officials who live in the US-protected Green Zone. "We too want the occupation to end, but the only way to do so is to stabilise the country by building political institutions while fighting [Sunni] terrorism."
The problem with the last version of reality is that security continues to deteriorate, despite the "handover of sovereignty" in the summer of 2004, last January's legislative elections and the October 15th referendum on the constitution.
Iraqi security forces are more visible in Baghdad, but they have not brought a sense of security. They speed down the streets, often against traffic, shooting into the air from the back of pick-up trucks resembling the "technicals" used by militiamen in Somalia.
These security forces are comprised mainly of Shia militiamen who are often indistinguishable from the criminals and insurgents they are supposed to be fighting.
A police Land Cruiser and a man in police uniform participated in the kidnapping of Irish journalist Rory Carroll last week. Men in police uniform kidnapped Margaret Hassan last year and the lawyer Saadoun Janabi, who was later found dead, last week.
A young man told me how three police cars came to the home of his best friend in the Hay Jihad district in early October. The "policemen" killed four brothers and their father because they ran a courier service that worked for the Americans. US forces are now reluctant to give weapons to the Iraqi security forces because the arms are often sold or given to the insurgents.
The entire US and Iraqi governments' exit strategy rests on turning security over to Iraqi forces. With Iraqi police and soldiers transmogrifying into insurgents, or implicated in ethnic cleansing, that strategy too is an illusion.