Erbil has changed a lot since I was there last. In early 2013, on my way into Syrian Kurdistan, I had stopped off in the city for a few days to make preparations. Then, the city had the feel of a boom town – shopping malls springing up across the skyline, brand new SUVs on the road, Exxon Mobil and Total were coming to town. It was the saf - est part of Iraq, an official of the Kurdish Regional Government had told me proudly over dinner in a garden restaurant. A new kind of Middle East city.What a difference a year makes.Now, Erbil is a city under siege.The closest lines of the Islamic State (IS) forces are 45 kilo - meters away.At the distant frontlines, IS (formerly ISIS) is dug in, its vehicles visible, waiting and glowering in the desert heat.The Kurdish Peshmerga forces are a few hundred meters away in positions hastily cut out of the sand to face the advancing jihadi fighters.The atmosphere in the city remains febrile. It is generally believed that were it not for the rapid intervention of the US Air Force after August 8, IS would have found its way into the city. The American air - strikes stopped the jihadis in their tracks. The land surrounding the city is flat, stark and bare. IS knows that if it seeks to push any further toward Erbil, its forces will be wiped out by American air power.Still, this is a temporary solution.“There was panic,” Iraqi Kurdish journalist Hiwa Osman tells The Jerusalem Report, when I ask about the early August days when IS seemed to be coming for the city like a juggernaut across the desert. “I was in Europe and I spoke to my wife. She described to me how cars were backed up trying to get out of the city. There wasn’t enough fuel. We think about 30 percent of the population left.”The exodus was in the direction of Dohuk and Zakho, further north and close to the Syrian border. The foreigners from the oil companies and consulates left too. The infrastructure of bars and restaurants that sprang up to cater to them, with staff from the Indian subcontinent and cold lager on tap, were all sad and empty. Only those too poor to leave or determined to fight would be there to meet the Islamists when they collided with the Iraqi Kurdish capital. But, as of now, their arrival has been stalled.Instead, a new population has arrived.These are refugees – Christians from the Mosul area, Yezidis from Sinjar Mountain.The religious minorities and the non-Arab, Kurdish-speaking Yezidis were well aware of what to expect when the Islamic State forces came for their areas, and the lucky ones made it as far as Erbil and sanctuary.Luck here is, of course, a relative concept. They are destitute.Their houses, goods and property are now in the hands of IS, or those of their Sunni Arab neighbors who chose to cooperate with them.You see them everywhere in Erbil.In the available spaces afforded by half- built apartment blocks, Yezidi refugees from Sinjar have planted their tents and are sheltering from the sweltering heat of August.In the yard of the Chaldean Church in the Ainkawa district, Christians from the Mosul area live in rows of tents, receiving food and consignments of ice from well-wishers and local people.In the evening when it cools down somewhat the city teems with people.There are other, earlier and less visible refugees.Working in the hotels are young men from Syria – some from government-con - trolled areas, some from the rebel zones. All crossed into Iraqi Kurdistan believing that here, at least, was a haven, a bastion from the sectarian war raging everywhere from the Iraq-Iran border to the Mediterranean Sea.The bastion has indeed held.The Peshmerga are still mustered in their positions past the city’s outer suburbs, but the Kurdish Region - al Government (KRG) has proved to be far more vulnerable than anyone suspected.My destination, however, was not Erbil. I was set to head north to Dohuk, then across the border into Syrian Kurdistan and south - ward as close to Sinjar Mountain as I could get.So, I set off on the highway for Dohuk.It was reputed to be safe, but it was hard to be sure.The frontline between the Kurds and the Islamic State is a huge and fluctuating affair, stretching all the way from Jalawla on the Iraq-Iran border to Jarabulus on the line between Syria and Turkey.But Peshmerga were deployed in force along the highway, and all was well.NEWS WAS coming in that the Kurds and Iraqis had recaptured the Mosul Dam, which provides water and electricity for Baghdad.American air support and probably the presence of US special forces on the ground were the decisive factor, once again, in the turning of the tide.From Dohuk, I travelled to the border crossing at Fishkhabur, or Semalka, as it’s known to the Syrian Kurds.This is a bor - der crossing like no other. It is jointly and efficiently maintained by two rival Kurdish nationalist movements, each with a very dif - ferent style and orientation, and neither of which is recognized by the world as having any right to police borders at all – a testimo - ny to the de facto fragmentation of Iraq and Syria, with which the Western world has yet to begin to grapple seriously.In the waiting room on the Iraqi side was one of the very saddest of sights in this bro - ken region – Syrian Kurdish families who had made their way to Iraqi Kurdistan a year earlier to escape the war in their home country were now petitioning to make the return jou r ney.They had made their calculation.IS has so far been kept firmly out of Syrian Kurdistan, defended by the lightly armed but formidable YPG militia.The vaunted Iraqi Peshmerga forces, though, had crumbled at Sinjar and Islamic State forces were just a few kilometers away, so they wanted to go back to Syria.“We tell them that if they go, they can’t come back again,” a KRG official at the border crossing tells me. “But they want to go anyway.”The borderline is the Tigris River.An old and rusty metal barge makes its way slowly across – from one Kurdish domain to the other.Syrian Kurdistan is an altogether more provisional and much poorer affair than is its Iraqi counterpart.Iraqi Kurdistan has been around as an autonomous entity since 1992.It possesses vast oil reserves on which it hopes to build its future prosperity.The three cantons carved out of Syrian territory by the Kurdish PYD (Democratic Union Party), meanwhile, are low on natural re - sources.But they are high on cohesion.The Kurdish administration that has been assembled on Syrian soil is very clearly the work of the PKK, Kurdistan Workers Party, with which the PYD is associated.PKK sent down cadres and fighters in the summer of 2012 to establish it.Though only lightly armed, the PYD’s YPG militia has successfully held off all attempts by IS to degrade the areas under its control.The result is that the inhabitants of “Rojava,” as it is called by the Syrian Kurds, are afforded a level of security available to few other population groups in Syria.Still, it is a meager life. Food is scarce, prospects uncertain. The Syrian war has been going on far too long. Fatigue and sadness are etched in the faces of everyone in a way that one does not yet see in Iraqi Kurdistan.In the town of Derik, the single hotel was full. I found myself housed in a YPG facility, in the company of a number of fighters wounded in a battle with IS in the town of Jeza’a further south a few days earlier.The Islamists were trying to interdict a corridor that YPG fighters had carved from Sinjar Mountain. Tens of thousands of Yezidi refugees stranded on the mountain had been saved by the corridor, which snaked through IS-controlled areas. The refugees were brought from the mountain to Jeza’a, Rumeilan and then the Newroz refugee camp.So the jihadis were trying to cut the road and the Kurds were fighting to prevent this. It had been a 17-hour close-range battle fought mostly with light weapons, with heavy losses on both sides. At its conclusion, the corridor was still open.The wounded fighters in Derik were exhausted. Still, they were happy to talk.“There is a British fighter here,” one of them tells me. “He will be here soon. You will talk to him.”I waited with interest in the little court - yard by the house for this British YPG fighter to make his appearance. I wasn’t quite sure what to expect. Foreign fighters on the Syrian battlefield are a phenomenon more usually associated with the Islamist forces than with the Kurds.Finally, he turned up and, with a smile, introduced himself. He was very obviously Kurdish, 32 years old, stockily built, with his arm in a sling, and speaking in a broad South Wales accent. He had immigrated to the UK with his family as a child and had grown up in Cardiff, where he now owned a restaurant with his brothers.So what led him from running a Kurdish restaurant in the Welsh capital to the YPG and the fight against the jihadis? “Well, I heard from my family what was happening,” he relates to The Report in his broad, musical accent. “My family’s from Diyarbakir, see. So I thought I had to do something. So I left my wife and kid, and came here to volunteer. My brothers are running the restaurant now. I trained for a couple of weeks, then straight into it.”And now, with a dislocated shoulder, he was contemplating his next step and remembering, with a deep and calm sadness in his voice, the details of the Jeza’a fight.“There must have been about 500 of them, about 90 of us. But they had no tactics, just kept coming forward. You should have seen when the trucks came to take away the bodies. Stacked up, they were.“I killed three of them. One was only a kid of 16. They just keep coming forward, and either you shoot them or they shoot you.That’s all.”He had been injured, not by a bullet but by a fall when he had to leap over a wall after an IS fighter threw a grenade, so the wound wasn’t serious. He was due to see his family, which had come to Diyarbakir from Wales.After that, he would decide on his future steps.From Drik, my fixer and I traveled to the Newroz refugee camp, temporary home to around 20,000 Yezidi refugees brought from Sinjar Mountain.Conditions at the camp were fairly primitive – rows of tents on an open plain with little protection against the blazing August heat. Still, the Yezidi refugee families we interviewed there were very clearly glad just to be alive.Again and again we heard similar stories – the rumors that the jihadis were approaching and then, usually in the small hours of the morning, their arrival; the rapid departure of the Peshmerga forces (a matter of particular bitterness for many of the refugees); and the attempt by the men of the village to mount a desperate defense of the area at least long enough to allow the women and children to escape.Then the days on the mountain. Many had died. Families had had to leave some of their most vulnerable members behind in the desperate fight for survival – the elderly, the infirm, many had been abandoned in the village. Their fate was mostly unknown. The assumption was that any man of an age to fight was dead. Younger women would have been taken to the slave market in Mosul, where women are sold for $25.On the mountain itself, hundreds died because of the lack of water in the blazing August sun. Aid packages dropped by American planes burst on the rocks of Sin - jar and were lost.Finally, after many days, the precarious corridor was opened and the surviving refugees began to leave the mountain.FEW HAD any desire to return. There was much bitterness against their Sunni neighbors for the many instances of collaboration with the Islamic State fighters. Instead, the general hope seemed to be to get to Iraqi Kurdistan, and from there to Turkey.I didn’t get all the way to Sinjar. There was heavy fighting still going on at Jeza’a and the YPG decided it was too dangerous to try and get through. But we got to the frontlines at Yarubiya where, in June, the YPG captured the border crossing and now control it from both the Syrian and the Iraqi sides. The IS are not far away. They control a neighborhood adjoining the border crossing. The civilian population are all long departed.There is a sniper’s war going on here and the YPG fire mortars across regularly when the IS sniper makes his appearance. The forward positions of the Kurds are draped with cloth and blankets to obscure the snip - er’s view. The neighborhood mosque, with its high minaret, is one of his favorite spots, I am told.“He can’t shoot so well, anyway, so don’t worry,” says Zilan, a commander of the female fighters of the YPJ, with a weary smile. Her fighters are deployed at the crossing alongside their male comrades.I tried hard to think about her words as one of her fighters, a tiny girl wearing a maroon Iraqi special forces beret she’d found at the border crossing, and I sprinted across a stretch of open ground to reach the forward position of the YPG, already several hundred meters into Iraqi territory.Morale among the fighters was high and they were keen to remind us of their record in recent days – the corridor to Sinjar, the capture of Yarubiya (“Tel Kocer” the Kurds call it); the inability of Islamic State to break into the isolated Kobani enclave, despite the weapons they had captured from the garri - son in Mosul.But the cost was very high, too. A day after Yarubiya, I attended a joint funeral of five YPG fighters from the town of Derik who had been killed in the Jeza’a fighting.The funeral took place on the parched plain outside the town. A long line of cars set out accompanying the vans holding the coffins. There were speeches from officials of the PYD and the YPG and singing. And finally as the sun sank, the YPG fighters took the shovels themselves and filled in the graves of the five very young men.“We have these funerals nearly every week,” one YPG fighter confided to me as we returned to the town. Behind the deter - mination and the war fervor, one sometimes hears a different tone reflecting sadness and disappointment. The Syrian war is now into its fourth year. Since it started all lives have been on hold. Even those, like the people of Derik, lucky enough to live in an area that has avoided the worst of the war’s ravag - es have been unable to move forward with their lives – to study, marry, buy a house – everything is frozen.Leyla, 23, visiting her brother who is a YPG fighter, tells The Report that Syria “used to be beautiful.” Then she reflects a little and adds “even though we weren’t allowed to speak Kurdish or even give our children Kurdish names. Anyway, it was better than ISIS. We used to be Syrian first and Kurdish second. That’s all changed now.Syria has gone. And we don’t yet know what’s coming to replace it.”This sense of being in transition is common to both the Iraqi and the Syrian parts of Kurdistan.In the meantime, however, there is the war. A huge and fluid frontline of 1,500 kilometers – all the way from the Iraq- Iran border to the line between Syria and Turkey. The Peshmerga, in cooperation with the US Air Force and the Iraqi special forces, are on the offensive now, determined to wipe out the shame of what happened on Sinjar Mountain. Important gains have been made.Still, Islamic State remains deployed close to Erbil at three separate points. Back in Iraqi Kurdistan, I toured the frontline at the Khazer area. I visited the second line of the Peshmerga forces, in the company of a group of senior officers.“The world still sees the KRG as part of Iraq,” General Maghdid Haraki tells The Report, as we sit in a tent at one of the Peshmerga positions in Khazer. “But since 2007, Baghdad has sent the Peshmerga nothing.Now we want direct aid.”They are a different type of force to the YPG. The fire and fervor is absent, more like a regular army. The commanders car - ry a little more girth. But they are what will defend the Kurdish capital from the jihadis – with a little help from the USAF.The frontlines near the city are silent for now. Islamic State is waiting a kilometer or so from the first Kurdish line.So, this is the war between Islamic State and the putative Kurdish sovereign entities to its north. The politics are complex, the military situation no less so. I left Erbil for Amman in the early hours of the morning.The streets were deserted but the refugees’ tents were still visible at the side of the road.Iraq and Syria, it appears, have become geographical expressions only.Political Islam in its various versions is fighting over much of what remains. The Kurds are standing for a radically different politics along a long line to the north. What is to come, and how all this – which may be just beginning – will end, remains hidden beyond the horizon.