We halted beside one of the three mini-palaces in the compound, and there on a shaded verandah, dressed in a long black dishdash and white headdress, was the beneficiary of all this protection: Sheikh Abd Sittar Bezea Ftikhan, a Sunni tribal leader on whose unlikely shoulders rest American hopes of reclaiming Ramadi and defeating al-Qaeda in Iraq.

While the world’s attention has been focused on Baghdad’s slide into sectarian warfare, something remarkable has been happening in Ramadi, a city of 400,000 inhabitants that al-Qaeda and its Iraqi allies have controlled since mid-2004 and would like to make the capital of their cherished Islamic caliphate.

A power struggle has erupted: al-Qaeda’s reign of terror is being challenged. Sheikh Sittar and many of his fellow tribal leaders have cast their lot with the once-reviled US military. They are persuading hundreds of their followers to sign up for the previously defunct Iraqi police. American troops are moving into a city that was, until recently, a virtual no-go area. A battle is raging for the allegiance of Ramadi’s battered and terrified citizens and the outcome could have far-reaching consequences.

Ramadi has been the insurgency’s stronghold for the past two years. It is the conduit for weapons and foreign fighters arriving from Syria and Saudi Arabia. To reclaim it would deal a severe blow to the insurgency throughout the Sunni triangle and counter mounting criticism of the war back in America.

Sheikh Sittar and US commanders believe that the tide is turning in their favour. “Most of the people are now convinced that coalition forces are friends, and that the enemy is al-Qaeda,” the 35-year-old Sheikh claimed in his first face-to-face interview with a Western newspaper.

“Al-Qaeda is now on the run,” Colonel Sean MacFarland, commander of the 5,000 US troops in Ramadi, told The Times at his headquarters just outside the city. But the four days The Times spent embedded with US forces in Ramadi last week suggest that al-Qaeda and its Iraqi allies are far from defeated, and that this is a battle with a long way yet to run.

“These are the worst days in Ramadi . . . the main groups are all fighting for control of the city,” said one resident, a health worker named Galib Awda.

More than fifty US soldiers have been killed in the city since Colonel MacFarland’s First Brigade Combat Team, part of the 1st Armoured Division, arrived in June, bringing the total to well over 250. US marine helicopters will fly to Ramadi only under cover of darkness.

Before being driven into the city from one of the four big US bases that surround it, I was instructed how, in an emergency, to pass fresh ammunition to the humvee’s machine-gunner. What could be seen through the vehicle’s bullet-proof windows was startling. Once a prosperous trading centre much favoured by Saddam Hussein, Ramadi has been laid waste by two years of warfare. Houses stand shattered and abandoned. Shops are shuttered up. The streets are littered with rubble, wrecked cars, fallen trees, broken lampposts and piles of rubbish.

Fetid water stands in craters. The pavements are overgrown. Walls are pockmarked by bullets and shrapnel. Side roads have been shut off with concrete barriers to thwart car bombs. Everything is coated in grey dust even the palm trees. The city has no functioning government, no telephones, and practically no basic services except sporadic electricity and water supplies. It has been reduced to a subsistence economy.

There are stray cats and wild dogs, but few cars or humans. Ramadi’s inhabitants have either fled, or learnt to stay indoors.

My destination was Eagle’s Nest, a “Combat Outpost” or COP, next to the wreckage of Ramadi’s football stadium where about 120 American and Iraqi troops have been posted since the summer to establish a presence in the city, monitor the terrorists and launch raids.

Times Recommends

• Rebel militias dig in as Russia leaves Georgia
• Lebanon's drug barons reap a bumper harvest
• A chilly wind is blowing down Main Street