“JUST walk down the street. Don’t turn back or look around,” said a huge man who was talking on a mobile phone as he approached. He neither paused nor turned his head, but carried on walking.

Two cars cruised slowly down the road. Fifteen minutes later, the same man reappeared. “Turn left,” he said. Soon afterwards an Audi A6 with tinted windows drew up. In the car was an elegant man in his thirties wearing an Italian suit. “We are very sorry for these complications, but we have to follow security procedures,” he said.

Arranging an appointment with Ibrahim al-Shammari, a representative of the Islamic Army, a leading Sunni insurgent group, had been fraught with tension, even though the meeting was in an Arab capital far from Baghdad. What began as a proposed rendezvous at a Kentucky Fried Chicken restaurant turned into a James Bond adventure.

The journey took a further hour and a half in two cars. Every now and then, new directions would be issued by phone. At last the car stopped outside a villa. A side door opened and a tall, lithe man with a light grey beard appeared. It was Shammari.

The Islamic Army is one of Iraq’s best known resistance groups, made up largely of former members of Saddam Hussein’s army and security forces. In a turnaround that heartened proponents of the US troop surge, it has lately been firing its weapons at Al-Qaeda in Iraq instead of American soldiers. The US military has been discreetly putting out feelers to the Islamic Army in the hope of winning it over permanently.

But Shammari had an uncompromising message for the Americans. The Islamic Army and other armed factions would agree to talks only if they accepted that the “Islamic resistance” was the legitimate representative of the Iraqi people and agreed to set a clear timetable for withdrawal from Iraq.

The government of Nouri al-Maliki, the prime minister, was finished, he boasted. “The final countdown has started. It has lost the support of Iraqis and the American people.”

It was hard to disagree when Senator Hillary Clinton, the front-runner for the Democratic presidential nomination, had just joined a chorus of US politicians demanding Maliki’s removal. She said she hoped the Iraqi parliament would replace him with a “less divisive and more unifying figure”.

Ryan Crocker, the US ambassador in Baghdad, told Time magazine, “the fall of the Maliki government, when it happens, might be a good thing”.

Yet many opponents of the US troop build-up, including Clinton, are coming round to the view that the surge is partially working – at least to the west of Baghdad in Anbar province, where Sunni tribesmen have been aiding Iraqi security forces and the Americans.

According to Shammari, however, the gains in Anbar will be shortlived. He said the Islamic Army had signed a ceasefire with Al-Qaeda in Iraq. The country was to be carved into spheres of influence where the Islamic Army and Al-Qaeda in Iraq could operate independently of each other. It would represent an enormous setback for the surge.

Shammari admitted Al-Qaeda in Iraq was unpopular. “Local people consider them enemy number one. They tyrannised people and killed and assaulted tribal leaders. They lost their bases and supporters and provoked the clans into rising up against them,” he said.

But the Islamic Army resents the way the Americans have tried to turn the infighting in Anbar to their advantage. “We’ve had big problems with Al-Qaeda ever since they began targeting and killing our men,” he said. “Eventually we had to fight back, but we found American troops were exploiting the situation by spreading rumours that exacerbated the conflict.”

The Islamic Army has also noted President George Bush’s comments about the success of the surge. “Bush foolishly announced to the world that all the Sunnis in Iraq were fighting Al-Qaeda so he could claim to have achieved a great victory,” Shammari said. “It’s nonsense.”

The Islamic Army is considering resuming the kidnapping of foreigners as a sign of renewed militancy, Shammari said. In the past, it was responsible for murdering Enzo Baldoni, an Italian journalist, and a number of foreign workers. It also kidnapped two French journalists who were later released.

“Every foreigner in Iraq is a potential target for us no matter what his nationality or religion,” Shammari said. “If he is proven to be a spy, he will be punished and an Islamic court will determine his fate.”

The purpose of taking hostages would not be to kill them, he added. “We want western governments to listen to the Iraqi people and stop supporting the occupation by sending their citizens to Iraq.”

The Islamic Army’s defiance sharpens the dilemma for American forces. Could progress in Anbar quickly unravel? If the US draws down its forces, will the Sunnis take the fight, not to Al-Qaeda, but to the Shi’ite government in Baghdad? And if so, will the US military have helped to build up a brutal sectarian force?

In Baghdad, Colonel Rick Welch, head of reconciliation for the US military command, told The Washington Post earlier this month that Sunni groups had recently provided 5,000 fighters for policing efforts in the capital.

But he admitted that Maliki’s government was “worried that the Sunni tribes may be using mechanisms to build their strength and power and eventually to challenge this government. This is a risk for us all”.

The National Intelligence Estimate, drawn up by US intelligence agencies and published last week, spelt out similar dangers. “Sunni Arab resistance to Al-Qaeda in Iraq has expanded in the last six to nine months but has not yet translated into broad Sunni Arab support for the Iraqi government or widespread willingness to work with the Shia,” it noted.

Back in the villa, Shammari said Maliki’s government would soon be gone. “The daily contradictions in the statements by American leaders about Iraq prove that the Iraqi resistance is going in the right direction.”

He added: “The next president should take prompt action to withdraw all US troops from Iraq.” And Gordon Brown should follow suit, he said, though he could hardly fail to be aware that plans for British withdrawal in the coming months are already advanced.

“The new prime minister should save Britain from the humiliating stupidity of Tony Blair and Bush and start withdrawing troops from Iraq now,” he said.

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