The vast desert region - where Sunni tribes rose up in 2006 and 2007 to drive out al-Qaeda with the Americans - has throughout 2014 been parcelled up, city by military camp, before the Iraqi government and U.S. forces could act.

Now Anbar's largest airbase Ain al-Asad, the Haditha Dam – a critical piece of infrastructure - and surrounding towns are encircled by Islamic State to the west from the Syrian border and to the east from militant-controlled sections of Ramadi.

IS has grown so strong over the last year that "they are like an octopus stuck to your face," said a Baghdad-based foreign diplomat.

Within Islamic State's grasp: an open route from the Syrian border all the way to Baghdad.

Sunni tribal fighters fear they are outmanned and say the U.S. military and Iraqi government are not sending enough support. Weapons are insufficient and U.S.-led air strikes are not dependable, the fighters say - even once they have tracked down the right commander or politician to relay a request for help.

"If it weren't for the tribal fighters then Anbar would have fallen," said Faleh Issawi, a member of the Anbar provincial council. "Eighty percent of the province is under the control of IS and the remaining 20 percent is under control of some security forces and tribal fighters."

Iraq’s main military divisions in Anbar - seventh, eighth, ninth, tenth and twelfth – have been badly damaged. At least 6,000 Iraqi soldiers were killed through June and double that number have deserted, say medical and diplomatic sources.

The picture is confused by the presence of ghost soldiers - enrolled men who do not turn up and fight but whose salaries go into the pockets of the commanders. The phenomenon has been associated with the shockingly fast collapse of the Iraqi army in the country's second-largest city of Mosul during the summer.

One Iraqi intelligence officer in Anbar estimated that while as many as 60,000 soldiers may be listed on the books in reality there are no more than 20,000 across the province.

In contrast the size of IS forces has not changed since the summer - when pro-government Sunni fighters were warning Anbar could fall - pointed out General Lloyd Austin, head of the U.S. military's Central Command.

Speaking to Pentagon reporters on Friday, Austin acknowledged Anbar's situation was fraught.

"I would describe Anbar as contested," he said.

SECTARIAN BURDEN

Iraq's army has also been burdened by a legacy of sectarianism in Anbar, whose dominant Sunni population resented former Prime Minister Nuri al-Maliki's Shi'ite majority government and were incensed when he ordered troops to clear a protest camp in Ramadi in late December 2013.

The ensuing Sunni tribal revolt prompted the entrance of Islamic State into Anbar’s two main cities – Falluja and Ramadi.

    The violence lasted months and until Iraqi Prime Minister Haider al-Abadi was sworn in this September, most civilians saw themselves as a target of the security forces.

Only now has there been an incremental shift among Anbaris, who wonder if the new government will make a true break with Maliki’s policies.

Abadi has imposed a ban on air strikes in residential areas, a dramatic shift from Maliki's actions, which caused the displacement of nearly 500,000 in Anbar province. He has also recruited major tribal figures, important during the last revolt against al Qaeda in 2006 and 2007, to join the security forces.

But the intelligence officer in Anbar warned that the war there was still being led by men appointed by Maliki.

And a provincial council member said the military leadership was failing the province with its bad planning.

"The enemy is overpowering us in numbers and equipment," the official said on condition of anonymity. "If a battle requires two regiments, the operation command sends only one – that cannot withstand the force of the enemy and falls within hours."

    That poor state of the army in numbers and equipment, coupled with the population's resentment towards Baghdad, has been exploited by Islamic State.

Lawmaker Hamid Mutalq, on parliament's security and defence committee, said these factors came into play when Islamic State seized the towns of Hit and Kubaisa in the middle of the province at the beginning of October.

    "Our forces are starting to buckle in the face of repeated assaults by the Islamic State," said one officer speaking on condition of anonymity.  "We lost control on most of the key roads around Ramadi and this made it too difficult to keep supplies flowing into the camps."

    He warned that equipment in the western part of the province from Ramadi was falling in disrepair.

    "Now most of our armoured vehicles and tanks are out of work and the evacuation process is getting too hard."

SURVIVING MINUTE TO MINUTE

    In far western Anbar, the Ain al-Asad airbase which supplies tribal fighters and Iraqi forces holding on to the Haditha Dam, is expected to hold out.

But the Iraqi government, the U.S. military and Iraqi forces have no ready solution for tribes whose towns are now encircled, not far from the airbase.

    In the village of Zuait albu Nimr, 45 kilometers northwest of Ramadi, the Albu Nimr tribe has been fending off Islamic State since the beginning of October.

    They have relied on air drops of small amounts of ammunition, but their survival is minute to minute.

"If our tribe falls, then that will deal a strong blow to all the fighting tribes in Anbar," said a tribal leader by phone, who wondered why U.S. fighter jets had not hit the jihadists surrounding them given that they were out in the open.

    "We gave the US forces the exact locations of some Islamic State positions … but they didn’t attack (most of) them."

The overflights have however acted as a deterrent to the militants, he added, saying the aircraft had disrupted Islamic State's resupply lines. The small army company attached to the community was not enough to defend them, he said, even if it had sufficient ammunition.

Trapped in their village, families had resorted to fire wood for cooking and, unable to reach their farms, were trying to grow vegetables in their back yards, he said. Women had had to deliver babies in their homes.

    "We have almost completely run out of supplies and are living on dates and water," the fighter said.

GATEWAY TO BAGHDAD

    The town of Amiriya Falluja - 40 kilometers southwest of Baghdad - was encircled by Islamic State tanks and armored vehicles for almost a week.

    General Faisal Zobaie, police commander for the town and who fought al Qaeda in 2007 in Falluja, told Reuters how he scrambled to reach the Americans and ask for air strikes to hit the massed fighters surrounding his community.

    He said he had met U.S. diplomats and officers at a meeting in Baghdad days earlier who had urged the fighters to flush out Islamic State fighters so the U.S. military could bomb them.

    So last Tuesday night, surrounded, Zobaie frantically called and texted Iraqi politicians and civilians whom he thought might link him to U.S. military command. By the time Zobaie reached U.S. contacts, the Islamic State fighters had hidden in neighboring villages and concealed their weapons.

Within days the community had been reinforced with an army unit. Even with that, an Islamic State suicide bomber in a humvee infiltrated the town and killed a brigadier general on Sunday. For the moment, a road south had been cleared. But IS still flanks the town to the north and has proven its ability to retake ground.

    Zobaie says he has begged the Iraqi government and the U.S. military to arm his policemen so they can fight back.

    "I swear I’ll take back Falluja if they give us the weapons," he said.