Abstract: A recent journey through northeastern Syria and northern Iraq provided an opportunity to see the multi-faceted campaigns against the Islamic State on several fronts, the handicaps and challenges that its adversaries face, and a sense of the real progress being made in degrading the group, compared to a previous visit to the region in February 2015. There are still issues, including notable animosities and deep-seated rivalries that persist among the different states and players that are supposedly on the same side of the conflict. These divisions provide the Islamic State with oxygen in its campaign to endure and expand. They also constrain U.S. and coalition action.

In late October and early November, the author spent two weeks traveling through northern Iraq and northeastern Syria as part of a CNN team reporting on the ground war against the Islamic State. The team went to Hasakah province in Syria and then Nineveh in Iraq. Most of the time it traveled with the dominant Kurdish factions in Iraq and Syria, but it also met Yazidi fighters, some of the internally displaced people of Iraq and Syria, and senior officials in the Kurdistan Regional Government (KRG) in Iraq.

The battle against the Islamic State is frequently hobbled by a lack of weaponry and equipment, as well as internal rivalries among the Islamic State’s adversaries, all of whom have their own patrons and often diverging priorities. Second, the scale of the Islamic State’s defensive preparations complicates the task of forcing the group from towns and villages they have spent a year and more fortifying—let alone from strongholds such as Deir Ezzour and al-Raqqa. Third, U.S. attempts to help prepare partners on the ground remain at best patchy, especially in Syria, and first-hand observation of air strikes around Sinjar tended to confirm that while they can make a critical tactical difference—the team observed one strike take out a truck suicide bomb just outside the town—their strategic effectiveness is limited.

However, there are signs that the Islamic State is under stress in critical areas. Its oil production, refining, and transport operations are being pummeled. Resupplying its crown jewel, the Iraqi city of Mosul, is becoming more arduous. Nearly 1.5 million people in the city live in deteriorating circumstances; those with relatives trapped there speak of growing paranoia among Islamic State officials, shortages, and price inflation.

The broader political landscape in the region changed beyond recognition in a few short weeks, following the bombing of the Russian Metrojet airliner, terror attacks in Paris on November 13, and the downing of a Russian Su-24 by Turkish planes later in the month. How these events will influence the battlefield and the relationships among key parties will only become apparent in time, but signs of a hardening response are already evident.

France has sharply escalated its airstrikes against al-Raqqa, on the grounds that the plot to carry out the Paris attacks was planned there. It is using its aircraft carrier, the Charles de Gaulle, which it moved to the eastern Mediterranean, as well as airbases in Jordan and the United Arab Emirates to stage the campaign. French Foreign Minister Laurent Fabius has even suggested coordination of rebel and regime forces against the Islamic State on the ground, a proposal that is a non-starter for factions inside Syria supported by Persian Gulf nations.

In the immediate aftermath of the Metrojet crash, Russia broadened its campaign of airstrikes to include the Islamic State’s oil business, claiming to have destroyed 500 fuel tanker trucks in the first few days of strikes.[1]

How Russia will respond to the downing of their Su-24 remains to be seen. Economic, visa, and trade restrictions against Turkey were quickly announced, but unless this crisis is defused in the near term, Moscow may seek to retaliate by providing greater support for the Syrian Kurds. There are already signs that the Democratic Union Party (PYD) and its military wing—the People’s Protection Units (YPG)—are benefiting from Russian airstrikes against other rebel groups (notably Jabhat al-Nusra and Ahrar al-Sham) north of Aleppo.[2]

Turkey regards the YPG as a terrorist organization in league with the Kurdistan Worker’s Party (PKK), which has fought the Turkish state for three decades. This complicates the on-the-ground situation. The YPG is already receiving support from the United States and other coalition partners—mainly through airstrikes—in its battles against the Islamic State. Russian support might encourage the group to defy Ankara and push west beyond the Euphrates River in order to achieve its aim of linking the cantons of its statelet, known as Rojava. Any expansion of Kurdish control across the Syrian border would shrink the Islamic State’s access to the outside world and deny valuable routes for its oil, fighters and supplies.[3] But Turkey has vowed to prevent such a move. The prospect of almost all its southern border being controlled by Kurds is something it will block, even if it means that the Islamic State remains in control of border towns such as Jarabalus.

A Patchwork Battlefield

Among the many parties battling the Islamic State on either side of the colonial-era border between Iraq and Syria are different Kurdish factions (as wary of each other as they are hostile to the Islamic State), Arab tribes, Yazidis, and Assyrian Christians. Government forces—either Syrian or Iraqi—are either absent or quiescent.

The major player among these ground forces is the KRG’s peshmerga in Iraq. Its size is estimated at around 180,000, distributed between the Interior and Peshmerga Ministries and local authorities. The formation of the Ministry of Peshmerga Affairs and U.S. aid has accelerated the process of integrating peshmerga brigades, but it is far from complete—and many fighters have police functions or are volunteers who rotate through frontline positions.[4] Even at the front many peshmerga are not of prime military age and must supply their own weapons. The author saw several fighters over the age of 70 at various frontline positions.

The Iraqi Kurds defend a frontline more than 600 miles long against the Islamic State, from south of Kirkuk to Sinjar near the Syrian border. They are thinly spread, often with small outposts of a dozen or so fighters at intervals of several kilometers. In the summer of 2014, the peshmerga were driven back to within 30 kilometers of the KRG capital Erbil by a lightning Islamic State advance. They were simply outgunned by a better-trained and equipped adversary that was able to field plundered armor, tanks, and mortars. But some Kurdish officials acknowledged privately that their military leadership had become complacent in the decade since the overthrow of the former Iraqi leader Saddam Hussein.[5]

The failure in 2014 caused a refocusing of effort. “This was the first time we saw peshmerga withdraw, and it had a deep impact on all the peshmerga and the whole of Kurdish society,” said Halgurd Hikmat, spokesman for The Ministry of Peshmerga Affairs.[6]

A winter offensive, heavily supported by coalition airstrikes, reclaimed some 500 square kilometers around Mosul, and the capture of Sinjar and its environs in November 2015 completed the reclamation of what the KRG considers Kurdish territory, according to multiple KRG officials.[7] There is no appetite, for example, for evicting Islamic State fighters from Tal Afar, a town that is sandwiched between Sinjar and Mosul and is a bastion of Sunni militancy.

In response to the Islamic State’s suicide bomb attacks, some peshmerga frontline units have been equipped with anti-tank missiles. The German government is providing some 500 MILAN missiles along with 30 launchers as part of a new $77 million military aid package.[8] The KRG also has U.S. AT4 anti-tank missiles and some 40 of the U.S. mine-resistant ambush-protected vehicles known as MRAPs.[9] But the vast majority of peshmerga units rely on AK-47s and pick-up trucks mounted with heavy machine-guns.

The KRG mobilized some 7,000 fighters[10] for the operation that freed Sinjar, but the operation’s success should be measured against the Islamic State’s decision to retreat rather than reinforce. As Denise Natali has observed, “At Sinjar, heavy coalition airstrikes, alongside ground support from Kurdish forces from Turkey and Syria, as well as Yezidi fighters, neutralized ISIL in the months before the actual liberation maneuver was launched. It was this combination of force, and not the presence of any single Iraqi Kurdish Peshmerga faction, that led to an ISIL retreat (or, as some say, a mere tactical withdrawal) without a lengthy urban battle.”[11]

The Kurds are still vulnerable to attacks along the frontline, evidenced by the assault on Dibis near Kirkuk, which came within kilometers of severing the main highway between Erbil and Kirkuk.

Complicating the Kurds’ effectiveness on the battlefield, the peshmerga are split between the two main political organizations in Kurdish Iraq: the Kurdistan Democratic Party (KDP) (the majority party led by President Massoud Barzani) and the Kurdish Union Party (KUP). The Ministry of Peshmerga Affairs was created to better synchronize the fighting force. But progress has been slow because political rivalries are never far from the surface, and recently turned fatally violent over the postponement of the presidential election in the KRG area.[12]

Intra-Kurdish Woes

The Kurds’ battlefield capabilities are further hobbled by rivalry between Iraqi and Syrian Kurds. The YPG, with an estimated 30,000 fighters, is the dominant force in northeastern Syria, though they are poorly equipped and lack training.

The focus of the tension between the KRG and YPG has been the Sinjar region just inside Iraq. The KRG was embarrassed by the sudden Islamic State takeover of the area in August 2014 and widely criticized for its inaction.[13] In contrast, the YPG fought to create an escape corridor across Mt. Sinjar for thousands of Yazidis fleeing the Islamic State. With the Syrian border just a few kilometers away, the YPG has remained in the area, highlighting its occupation with a base and a massive portrait of PKK leader Abdullah Ocalan painted onto a mountainside. The tension between the KRG peshmerga and Syrian Kurdish fighters was palpable during the author’s trip: both sides flew their banners and flags prominently and mounted their own roadblocks.

Ultimately, the operation to take Sinjar was led by KRG peshmerga and supported by Yazidi volunteer units cobbled into an auxiliary force under peshmerga control. The military wing of the PKK complained loudly at being excluded. “We can make no sense out of this unfriendly attitude,” was a representative quote from YPG leaders, according to news reports.[14] Similarly, the Sinjar operation was devoid of Arab participation, despite the area being ethnically mixed. “One important excluded group was the Sunni Arab Shammar tribe that controls the Rabia border region with Syria, cooperates with Barzani, has a good relationship with the Yezidi, and had hundreds of fighters ready and willing to help liberate Sinjar,” Natali noted.[15]

Further complicating the picture in this area are acts of vengeance by Yazidi militia against Arabs and some Kurds whom they regard as having collaborated with the Islamic State during the 16 months its forces occupied the area.[16]

The KRG’s hard line toward its fellow Kurds is partly because the KDP does not tolerate competition where it is the dominant party.[17] The KRG also has a close relationship with the Turkish state. Iraqi Kurdistan is heavily reliant on Turkey for investment and as a conduit for its oil, which is shipped northward independent of Baghdad and the central Ministry of Oil. KRG President Massoud Barzani cannot afford to alienate Turkish President Recep Tayyip Erdogan, newly emboldened by election victory. Amid a multi-pronged offensive against the PKK, which has included months of airstrikes on the group’s bases in northern Iraq, Turkey has put pressure on the KRG to interrupt the flow of foreign fighters trying to join the YPG, according to sources in the region.[18]

Further evidence of the close relationship between the KRG and Ankara came with the reinforcement of a Turkish military training mission in KRG territory in early December. The Turks are helping to train former Iraqi police and soldiers at a base north of Mosul.[a]

Were the YPG and KRG to coordinate their actions against the Islamic State, pressure along crucial axes that connect Islamic State territory in Syria and Iraq might be more effective. The establishment of a U.S. Special Operations Task Force in Erbil may improve the situation, along with the arrival of small units of U.S. special forces on the ground in northern Syria to help train and coordinate the YPG’s efforts. As The Institute for the Study of War puts it: “The deployment of reportedly up to 200 Special Operations Forces (SOF) with authority to engage in raids in both Iraq and across the border in Syria follows an intensification in U.S. activity under advise and assist in support of the peshmerga in Iraq.” [19]

The U.S. government clearly recognizes the potential offered by Kurdish forces for degrading the Islamic State in this critical theater, but there remain substantial logistical and diplomatic obstacles to exploiting that potential.

The Hasakah Front

Over the past year, the YPG has shown itself (by the relative standards of rebel factions) to be a proven partner against the Islamic State in northern Syria. After saving the border town of Kobani last year with help from coalition airstrikes, it has denied much of the Turkish border region to the Islamic State. The YPG was also able to forge an alliance with some Arab factions in what was known as the Euphrates Volcano operations room.[20]

The YPG has insisted that before the Syrian regime can be confronted, the Islamic State must be eliminated—a view that’s popular in Washington but less so among many Arab rebel groups in Syria. There is significant criticism that the Kurds stood to one side when the uprising against Syria’s President Bashar al-Assad began in 2011.

Even so, the YPG is the senior partner in a new coalition that includes Arab factions and Syrian Christians under the umbrella of the Syrian Democratic Forces (SDF). Its members include the Sanadid force (dominated by the Shammar tribe), the Christian Syriac Military Council, the Jazira Brigades, the Turkmen Seljuk Brigade, and Jaysh al-Thuwar, which is made up of moderate Arab factions previously expelled from northeast Syria by Jabhat al-Nusra.[b]

The non-Kurdish constituents can, at best, field fighters in the low thousands, and in many instances their training is non-existent. They are more akin to defensive neighborhood militia. After 50 tons of U.S. ammunition was dropped to the new alliance in October, U.S. officials “privately acknowledged that the Arab units it was intended for did not have the logistical capability to move it. So, again, the Kurds were called to help.” [21]

Yet to be demonstrated is the degree of cooperation in the field among the SDF factions, whether in Hasakah or further west.

YPG fighters—including the Women’s Protection Units (YPJ)—display exceptional determination and courage. Some have been trained by the United States in the use of hand-held GPS devices to call in airstrikes, acting as forward air controllers for the coalition. But a tour of frontline positions suggests that tactically, and in terms of organization, communication, and equipment, the YPG needs further help, especially with demining, transport, and defensive armor.

Its most recent focus has been on pushing Islamic State forces further south, out of Hasakah province altogether. In November, the YPG began probing attacks on Islamic State positions closer to Deir Ezzour, a critical supply and communications hub between al-Raqqa and Mosul. Again, airstrikes helped pave the way, with multiple attacks against the Islamic State strongholds of al-Hawl and Ash Shaddadi. At the end of October, heavy plumes of smoke could be seen hanging over the area for days at a time, though that may have been in part due to oil fires used by the Islamic State fighters to obscure their movements.

The YPG offensive made progress despite heavy mining by the Islamic State around its defensive positions.[22] The Islamic State abandoned al-Hawl near the Iraqi border toward the end of November. Ash Shaddadi, 46 kilometers south of Hasakah city, is the next key objective because it is on a critical Islamic State resupply route, but it is allegedly encircled by improvised explosive devices (IEDs) and landmines intended to funnel an attacking enemy into a kill zone. According to Kurdish commanders on both sides of the border, the Islamic State has also invested more heavily in conventional defensive fortifications in recent months, including long trenches and networks of tunnels that shield their fighters’ movement from the enemy.

YPG commanders do not envisage taking a leading role closer to Deir Ezzour. They regard it as an Arab city where Kurdish fighters would not be welcome and where losses would likely be high. It’s unclear what ground forces acceptable to the Western coalition would be capable of such an assault, which would require a force of some 20,000 according to YPG commanders. There is the added complication of regime forces close by, holding out at Deir Ezzour airport.

The Turkish Question

The United States has to walk a tightrope in its relations with the YPG because of Turkish hostility to the group. U.S. officials have been at pains to insist that the SDF will operate only to the east of the Euphrates.

“They [the YPG] have been effective,” said State Department spokesman Mark Toner. “But we also have talked about some of the caveats—that we don’t want them developing some kind of semi-autonomous zone.”[23]

Ankara has been explicit in saying it will prevent the YPG from creating a contiguous zone along the Syrian border by moving beyond the river, even though to do so could deny the Islamic State access to Turkey.

In a CNN interview on November 9, Turkish Prime Minister Ahmet Davutoglu said Turkey would take all measures to stop arms shipments to the YPG. “We will not and we cannot …tolerate any help to any PKK-related groups in Syria or in Iraq,” he said.[24]

At the end of October, Turkish forces opened fire several times on YPG units that were allegedly trying to cross to the west bank of the Euphrates. The Erdogan administration may have been hoping for return fire to provide a pretext for escalating offensive action, but YPG forces showed restraint. Even so, the desire of the coalition to transform the Syrian Kurds and their allies into a ground force capable of putting pressure on al-Raqqa will likely be constrained by Ankara.

Kurdish forces and their allies hold Tal Abyad, but their ability to apply pressure on Jarabalus, an important border town held by the Islamic State, is hobbled by the de facto Turkish veto. Erdogan has accused the Kurds of a form of ethnic cleansing as they advance. “Who owns that place?” he asked of Tal Abyad. “Ninety-five percent of the people in that town are Arabs and Turkmens, with 5% Kurds. Their goal was to turn that place into a canton, and that is what they did. This is now posing a threat to Turkey.”[25] Salih Muslim, the leader of the PYD, responded by saying: “[The Islamic State] is slaughtering women and children west of the river, but Ankara doesn’t say anything about that. To say the YPG must not move to Jarabalus only means let [the Islamic State] do what it wants.”[26] It was a complaint later taken up with gusto by Russia.

Islamic State Under Pressure

Despite the many difficulties in stitching together a workable coalition against the Islamic State in northern Syria, the group is under pressure there and in northern Iraq. There are multiple reports that families of foreign Islamic State fighters have begun leaving al-Raqqa for Mosul since French airstrikes intensified.[27] The capture of Sinjar and Route 47 linking al-Raqqa and Mosul has forced the Islamic State to find more circuitous and difficult routes through Ba’aj. Kurdish sources in Iraq say the Islamic State has moved road-building equipment into the area.[28]

Even so, the capture of Route 47 has exacerbated shortages in Mosul and stoked price inflation for basic goods, according to sources familiar with the situation inside the city.[29] The Islamic State’s difficulties in the area straddling the Syrian-Iraqi border have been multiplied by a much more concentrated air campaign in support of YPG advances south of Hasakah and against the Islamic State’s oil facilities in the area.

The Islamic State has been pumping an estimated 30,000 barrels of oil daily, according to several estimates, of which a significant portion comes from the al-Jabsah and al-Omar fields in northeastern Syria.[30] That source of revenue is now under much greater pressure.

In the two months to the beginning of December 2015, U.S., French, British, and (uncoordinated) Russian airstrikes targeted oil refineries, transport, and storage facilities held by the Islamic State around Deir Ezzour. On November 18 alone, U.S. ground attack aircraft struck nearly 300 oil tanker trucks near the town, according to U.S. officials.[31]

It was the second attack of such intensity within a week and may have prompted the Islamic State to change its system for transporting oil. Previously, long lines of trucks would wait for refined products; now they are called one-by-one to collection points, according to sources in the region.[32] The Russian Defense Ministry has claimed its jets have also been hunting oil tankers in this area and had attacked fuel dumps north of Deir Ezzour. In early December, British jets targeted the al-Omar oilfield, one of the largest still under the Islamic State’s control.

The Islamic State remains a resilient organization with sophisticated military tactics, an extraordinary capacity to produce improvised explosive devices (IEDs), and a complex bureaucracy that manages everything from taxation to the supply of ammunition to frontline positions. It still has thousands of seasoned fighters in the field and has enjoyed success in other parts of Syria in recent months, especially round Aleppo and in the Homs countryside. And while it has lost ground in northern Syria, its main positions remain intact. Several factors could yet derail progress against the Islamic State in the Syrian governorates of Hasakah, Deir Ezzour, and al-Raqqa, especially rivalry among its adversaries.

Even so, there is no denying that the Islamic State has lost territory, access to highways, and control of resources in this area, as well as seeing its access to Turkish soil eroded.

The Next War?

The fractured nature of the battlefields on either side of the Iraqi-Syrian border mean that the Islamic State is neither the only enemy nor even the most critical enemy for some forces. Amid the kaleidoscope of rivalries, one that could play in favor of the Islamic State is the growing tension between the KRG and Shia militia, which is nibbling at the Kurds’ sphere of influence.

One peshmerga general close to KRG President Massoud Barzani said he feared the the Shia Asaib Ahl Haq and Badr militia more than he did the Islamic State.[33]

These militia—known as Popular Mobilization Units (PMUs)—have overshadowed Iraqi security forces as the sharpest offensive group in operation against the Islamic State in non-Kurdish parts of Iraq. The weakness of the Iraqi Security Forces has prevented Iraq’s Prime Minister Haidar al-Abadi from consolidating his authority in the face of the militia, which led the battles to retake Tikrit and Baiji. The Islamic State has worked hard to stoke fear of the PMUs among Sunnis in areas that it controls. According to one source it moved busloads of Sunni civilians from Tikrit to Mosul so they could spread work of the atrocities committed by the militia.[34]

The Kurds are apprehensive of these militias’ ambitions north of Baghdad and around the city of Kirkuk. The city hosts a mix of ethnic and sectarian groups, but its status as part of the KRG is non-negotiable for the Kurds. The peshmerga swept into the city in June 2014 as it was abandoned by Iraqi security forces in order to prevent the oil-rich area falling into the hands of the Islamic State. While Arabs make up much of the police force in Kirkuk, it is the Kurdish militia and police force that carry out almost all security functions.

The Shia militia are the most obvious evidence of Iran’s influence in Iraq, and Kurdish commanders say senior officers from the Iranian Qods Force are a regular fixture in the area. The Kurds do not coordinate with the PMU in the fight against the Islamic State, according to the Minister of Peshmerga Affairs, Mustafa Sayid Qadir. “We do not have any cooperation with them and we are not happy to have them closing in on our [KRG] borders,” he said earlier this year.[35]

The KRG, for example, insists that the multi-ethnic town of Tuz Khormato, which lies between Kirkuk and Baghdad, is within its territory. This has led to clashes between the al-Hashd al-Shaabi and peshmerga, with the Turkmen community caught in the middle. In October, 16 people were killed amid Kurdish-Shia clashes in the town, and the road linking Baghdad to Kirkuk was severed for a time. The Islamic State is seeking to exploit these tensions, claiming a car bomb attack in Tuz Khormato at the end of November that killed five people.[36]

Across the border in the self-proclaimed cantons that make up the Syrian Kurds’ self-declared statelet of Rojava, similar resentments are brewing. Some Arab villages around Hasakah have been abandoned; in others the population can barely disguise its sympathy for the Islamic State. The YPG talks constantly of reconciliation, and its communiques advertise joint actions with other groups in the Syrian Democratic Forces. It has some Arab allies among the tribes of the north, especially the Shammar, who see the Kurds as the lesser of two evils. But Amnesty International has reported human rights violations by the YPG, including the clearance and destruction of villages as its fighters reclaimed territory from the Islamic State this year.[37]

The Sharabia are one group at odds with the newly dominant Kurds in this area and in the words of one analysis, “many of the Arab belt settlers probably fear that the Kurds will eventually want to evict them and take back their property.”[38]

There were several days of clashes pitting the YPG and its allies against other Syrian groups around the border town of Azaz and the Aleppo suburb of Sheikh Maqsud. One of those groups, Liwa Ahrar Suriya, accused the YPG of cooperating with Russia in trying to cut rebel supply lines to Aleppo. Each side accused the other of killing civilians. A truce was arranged on December 3 between the YPG and the Aleppo Conquest Operations Room.[39]

A journey across this region is a painful reminder that even if the Islamic State’s control of territory shrivels and disappears, it will likely retain the ability to wage insurgent warfare, thanks in no small part to overlapping territorial, communal, and sectarian disputes among its adversaries, the massive displacement of civilians, and the absence of meaningful reconstruction in areas already wrested from Islamic State control.

Tim Lister has been a journalist for more than 30 years with the BBC and CNN. He has traveled extensively in the Middle East and was at Tora Bora in Afghanistan in late 2001. This year he has covered the terror attacks in Tunisia and France and written extensively about the Islamic State for CNN.com. He is co-author with Paul Cruickshank and Morten Storm of Agent Storm: My Life Inside al Qaeda and the CIA. Follow @TimListerCNN.

Substantive Notes

[a] The Iraqi government protested the Turkish military presence in KRG territory without Baghdad’s consent. The Turkish ambassador to Iraq was summoned to the Foreign Ministry on December 4. “Iraq summons Turkish ambassador to demand withdrawal of troops,” Reuters, December 5, 2015.

[b] The announcement establishing the SDF was made on October 11, 2015, with the preamble stating: “Due to the accelerated conditions in both the political and the military development and the sensitive phases our country has gone through, there must be an establishment of a unified national military force to all Syrians consisting of Kurds, Arabs, Assyrians, and all others living in the geographical locations of Syria.”

Citations

[1] “Russian jets ‘hunting’ IS oil tanker trucks: Defense ministry,” Agence France Presse, November 18, 2015.

[2] Roy Gutman, “Russia has stepped up bombing since Turkey downed its aircraft,” McClatchy, December 5, 2015.

[3] See Metin Gurcan, “Meetings between Turkish, Russian military reveal Moscow has been warned.” Al Monitor, November 30, 2015

[4] For analysis of the Kurdish-US relationship, see Michael Franks: “Last Man Standing: U.S. Security Cooperation and Kurdistan’s Peshmerga,” The Washington Institute, July 24, 2014.

[5] Author’s interviews with KRG officials, February and October 2015.

[6] Isobel Coles, “Outgunned and untested for years, Kurdish peshmerga struggle,” Reuters, August 13, 2014.

[7] Author’s interviews with KRG official, October 2015.

[8] “German Defense Minister Praises Growing Trust with Iraqi Kurds,” Rudaw News Agency, October 27, 2015.

[9] U.S. supplies were detailed in a letter from US Secretary of Defense Ashton Carter to Senator John McCain (R-AR), June 10, 2015.

[10] Author’s interviews with peshmerga commanders, October 2015.

[11] Denise Natali, “Lessons from the Liberation of Sinjar,” War on the Rocks, November 25, 2015.

[12] For example, see Matthew Schweitzer “Troubles in Kurdish Paradise,” Le Monde Diplomatique, November 27, 2015. See also Hoshang Waziri and Lydia Wilson, “Haunted By Their Past: Kurds and the Islamic State,” CTC Sentinel, 8:6 (2015).

[13] See Cathy Otten, “Kurds Retake Sinjar from ISIS, Almost Too Easily,” The Daily Beast, November 13, 2015.

[14] “HPG Command: KDP Forces Us to Leave Shingal,” ANF news agency, November 2, 2015.

[15] Natali, “Lessons from the Liberation of Sinjar.”

[16] Interviews in the Sinjar region, October 2015.

[17] Saad Solloum, “Yazidi infighting, disputes over Sinjar stall battle against Islamic State,” Iraq Pulse, Al Monitor, August 18, 2015. For example, Yazidis were told they could only form military units under the peshmerga umbrella; they could not fight for Sinjar as an independent force.

[18] Interviews with YPG commanders and foreign fighters serving with the YPG.

[19] Institute for the Study of War, “Iraq Situation Report November 20 –December 2, 2015.”

[20] On the ‘Euphrates Volcano’ see Jonathan Steele, “Syrian Kurdish leader hails ‘Euphrates Volcano’ fight against ISIS,” Middle East Eye, September 12, 2014.

[21] Ben Hubbard, “New US Backed Alliance to Counter ISIS in Syria Falters.” New York Times, November 2, 2015.

[22] Author’s interviews with YPG officials, and “US Backed Syrian Democratic Force5 Recapture New Areas from ISIS,” ARA News, December 1, 2015.

[23] Mark C. Toner, Deputy U.S. Department of State Spokesperson, Daily Press Briefing Washington, D.C., November 10, 2015.

[24] “Turkish PM Pledges ‘a New Turkey,’” Interview with Christiane Amanpour, CNN, November 9, 2015.

[25] Fehim Tastekin, “Is Turkey Setting a Kurdish Trap?” Al Monitor, October 29, 2015.

[26] Ibid.

[27] The French Defense Ministry announced there were 20 strikes on November 15 alone, targeting several locations in Raqqa, including a training camp for foreign fighters.

[28] Interviews with Kurdish officials and analysts.

[29] Interviews with analysts and activists familiar with the situation inside the city, October 2015.

[30] For a superb overview of the Islamic State’s oil trade, see Erika Solomon, Guy Chazan, and Sam Jones: “Isis Inc: how oil fuels the jihadi terrorists,” Financial Times, October 14, 2015.

[31] Jim Miklazweski, “US destroys 280 ISIS Oil Trucks in Syrian City of Deir Ez-Zor,” NBC News, November 23, 2015.

[32] Erika Solomon, “Upsurge in Airstrikes Threatens ISIS Oil Production,” Financial Times, November 18, 2015.

[33] Interview conducted in October 2015.

[34] Interview in Erbil. October 2015.

[35] Alex Vatanka and Sarkawt Shamsulddin, “Forget ISIS; Shia Militias are the Real Threat to Kurdistan,” National Interest, January 7, 2015.

[36] “Explosives-laden car seized at Tuz Khurmatu checkpoint,” NRT, December 1, 2015.

[37] “Syria: US ally’s razing of villages amounts to war crimes,” Amnesty International, October 13, 2015. The PYG rebutted the Amnesty report in detail and said it would “contribute greatly to the deepening of ethnic tensions and portrays things as a sectarian war between Kurds and Arabs.”

[38] Carl Drott, “Arabs Split Between Kurds and Jihadists,” Carnegie Endowment for International Peace, May 15, 2014.

[39] “YPG and Fath Halab Operations Room Sign Truce in Aleppo,” SITE Intelligence Group report, December 3, 2015.