On Monday, Isis jihadists, backed by local Baathist remnants from Saddam's old regime, overran Tal Afar, causing the exodus of most of the city's Shias.
"It is Baathists from Tal Afar who enabled Isis to take over the town. They have a strong presence and are very well organised," said one senior Iraqi intelligence officer from the area.
"This is the return of Saddam's men."
The officer spoke standing on the front line, 12km from Tal Afar towards the Kurdish town of Sinjar on the Syrian border. He stood with Kurdish peshmerga forces who are now protecting the area, which marks the edge of the territory that Isis controls.
Dozens of peshmerga troops, armed with rifles and machine guns mounted on pick-up trucks, manned the road.
They waved down cars from Tal Afar and, afraid of suicide bombers, pointed their guns at the drivers, their fingers on the triggers if they failed to stop. To the side, standing behind a dirt bank, peshmerga forces scanned the desert for signs of an Isis assault.
In the near distance, less than 1km away, two US Humvees circled in the desert scrubland. "Those are Isis and other insurgents," said one peshmerga fighter, hailing his commanding officer.
Another peshmerga fighter, manning a heavy machine gun, swivelled the barrel in the cars' direction.
Since the morning the insurgents had been running "reconnaissance missions" in the area, at one point driving along a dust road that came within less than 100m from the peshmerga front line, the fighters said.
Tal Afar is one of several towns to have fallen to the Sunni insurgents in recent weeks; but its capture is of enormous importance due to its history as a symbol for what Condoleezza Rice, then US Secretary of State, called the "clear, hold, and build" operation.
The Americans first arrived in Tal Afar, a mostly Turkmen town of Sunni and Shia Muslims, in 2004 to fight men loyal to Saddam. They took the town but, after they left it poorly defended, it fell again to Sunni Islamists.
In 2005, the US began "Operation Restoring Rights", in which areas were to be purged of insurgents, but then rebuilt to win the "hearts and minds" of the locals. Eventually they were to be handed back to the Iraqi military.
More than 5000 US troops were sent to the city. They pushed out the insurgents and spent millions investing in the local security services.
In March 2006, President George W. Bush held up Tal Afar as a "success story", showing "the outlines of the Iraq we've been fighting for".
The remnants of the US investment can be seen driving from Sinjar towards the front line. Amid the mountainous scrubland stand abandoned military bases that once housed US troops: huge structures surrounded by concrete bomb-blast pillars.
Peshmerga troops now wear the military equipment provided to them by the US during the war. Three of the men who accompanied the Daily Telegraph to the front line wore camouflage T-shirts with "US Army" on the front. But in the town, history has been reversed.
Jafar, 32, a former Iraqi soldier who fought alongside the Americans, said: "I know of many of the Sunni insurgents who are back. These are the same people who, when the Americans left Iraq, came to threaten my family."
Refugees who fled Tal Afar also confirmed that the "same men who were fighting against the United States are now fighting with Isis".
A commanding officer on the front line for Tal Afar said the Baathists and Isis were now one and the same. He is in continual radio contact with Iraqi Army members fighting the insurgents from an airport near the city.
The co-ordination between the Baathists and Isis is an alliance of convenience, residents said.
Isis follows a much more extremist interpretation of Islam than the traditional Baathists, but both are now hell bent on ousting the Shia-led Government of Prime Minister Nouri al-Maliki.
