Operation Olive Branch, the military operation against the Kurd-administered enclave of Efrin in northern Syria launched by Turkey on Saturday has sparked fears that a new phase in the seven-year-old conflict could be ignited in an area that has been relatively stable.

Sinam Mohamed, a Washington, D.C.-based representative of the Democratic Federation of Northern Syria which administers both Efrin and Manbij told reporters on Tuesday that, after Efrin, Turkey will target all of northern Syria.

Russia has said plans by the U.S.-led Coalition to create a border security force in Syria provoked Turkey into launching Operation Olive Branch. Turkey’s President Recep Tayyip Erdogan said Turkey and Russia have an agreement to allow Turkish aircraft to fly in Efrin.

On Wednesday, U.S. President Donald Trump spoke to Erdogan and “relayed concerns that escalating violence in Afrin, Syria, risks undercutting our shared goals in Syria,” according to a White House readout of the Trump-Erdogan conversation later disputed by Turkish officials.

According to the readout, Trump “urged Turkey to exercise caution and to avoid any actions that might risk conflict between Turkish and American forces.”

But, will Turkey attempt to capture Manbij, and is the creation of the border force the real reason for Turkey’s military intervention in northern Syria? We asked five experts for their thoughts ahead of Trump’s phonecall.

“Manbij is an old obsession of Turkey”

Nicholas A. Heras, a Fellow in the Middle East Security Program at the Center for a New American Security and a Senior Analyst at the Jamestown Foundation told The Defense Post that Turkey’s long-planned operation is unlikely to include an assault on Manbij.

“Manbij is an old obsession of Turkey, and the SDF control over Manbij has been a special irritant for Erdogan,” Heras said. “The Turks firmly believe that former Vice President Joe Biden sold Erdogan a lie when he told them that the Obama administration would not allow the SDF to cross onto the western bank of the Euphrates River to capture and administer Manbij.”

Manbij was captured from Islamic State on August 12, 2016 by the U.S.-backed Syrian Democratic Forces after a 75-day battle, later named “Operation Martyr and Commander Faysal Abu Layla” after the commander’s death. Fighters from the predominately Kurdish People’s Protection Units (YPG) and Women’s Protection Units (YPJ) made up the vast bulk of those deployed in the operation, and the YPG said it handed its points of control west of the Euphrates river to Manbij Military Council as it had agreed ahead of the offensive. Turkey has long disputed this version of events.

Heras said that the capture and subsequent administration of Manbij by the SDF was a “key catalyst” for Operation Euphrates Shield, which Turkey launched later in August 2016 to prevent the joining of Efrin “with SDF core areas of control east of the Euphrates River.”

Euphrates Shield saw fighting between Turkey-backed forces and MMC, eventually resulting in the capture of territory from the SDF.

In March 2017, the U.S. confirmed that it had deployed forces to the Manbij area to reassure the SDF and deter hostilities between factions on the ground.

Within days, Russia also deployed forces in the area, prompting Air Force Colonel John Dorrian, then spokesperson for Operation Inherent Resolve, to say that U.S. and Russian forces could see each other near Manbij, but that they’re not “hanging out together.”

Heras said that Turkey has been planning Operation Olive Branch “for at least a year and a half” as a follow-on to Euphrates Shield. That operation, which saw Turkey-backed Free Syrian Army elements push out ISIS from a number of significant towns, eventually secured a large area of Turkey’s border region with northern Syria, surrounding the SDF-held Manbij area to the north and west, and leaving Efrin as a western enclave.

“That decision to launch Operation Euphrates Shield was intended to cut off a contiguous Syrian Kurdish zone of control across most of Turkey’s borders from northeast to northwest Syria,” Heras said.

Despite Turkey’s public pronouncements that it would launch an offensive or support an FSA drive to capture Manbij, Heras said that “the presence of Russian and U.S. forces in the area of Manbij inhibits Turkey’s freedom of action. Turkey does not want to get into a shooting match with Russia and the United States over Manbij, which could have greater consequences for Turkey beyond Syria.”

Heras argues that instead, Turkey could “turn the tap” on a nascent Arab insurgency in the Manbij area to undermine SDF security and governance structures there.

“There are already Turkish-backed Arab groups that are waging a small-time insurgency against the SDF in and around Manbij, and Turkey could use that to its advantage, particularly with the Turks’ ability to network with and finance Arab armed opposition leaders and tribal leaders,” Heras said.

Manbij is “a different can of worms” to Efrin

Aron Lund, a Fellow with The Century Foundation, agreed that Turkey has “been eager to do something about Afrin for a long time,” but that a Turkish military operation against Manbij is unlikely.

“I don’t think the U.S. announcement of the border force triggered the Turkish attack,” Lund told The Defense Post, adding that Turkey has been talking to Russia and reorganizing and training their Syrian rebel allies “since summer or autumn, not just aiming for Afrin but certainly with Afrin as part of the discussion.”

“Let’s see what happens in Afrin before speculating too much about Manbij,” Lund said. “That’s a different can of worms, since you have U.S. troops there and it’s integrated with the Pentagon’s counter-IS efforts. Turkey might hope to replicate a successful Afrin operation in Manbij, too, but that would require talking to the Americans – Russia can’t really help them there.”

Lund described Turkey’s October intervention in Idlib as “weird and hard-to-read.”

“It appears to have been partly negotiated with Russia and partly with jihadis in Syria. But whatever the process behind it, the Turks ended up plopping down a line of military outposts along Afrin’s southern border. I think that gives you a good idea of where Erdogan’s mind was at that time. They’ve had Afrin in their sights for a long time, since it’s the one area of Syrian Kurdistan that isn’t covered by the U.S. Air Force. In that sense, it’s low-hanging fruit for Turkey. Or if not low-hanging, at least not fruit protected by a superpower,” Lund said.

Russia may prefer a Kurdish presence

Kristian Brakel, Foreign Policy Analyst on the Middle East and Turkey at the Heinrich Böll Foundation in Istanbul, who was previously an Associate Fellow at the German Council on Foreign Relations, is similarly cautious.

“I do not think that Russia has greenlighted an operation that would advance beyond the Afrin canton,” Brakel told The Defense Post. “I think neither the U.S. nor Russia wants Turkey in Manbij.”

Brakel agreed that the announcement of the Border Security force may have “facilitated a quicker deployment of forces, but it is likely that it would have happened anyway.”

“The Turkish government started speaking about it already two years ago – although not in very concrete terms,” Brakel said.

Brakel says that Russia may see the Efrin operation as an opportunity for its Syrian government ally to capture parts of Idlib province from ISIS and al-Qaeda-linked factions while FSA elements are fighting in Efrin.

“But in the end Turkey is expanding a conflict that Russia wants to end and Turkey wants to gain a better negotiation position for talks to come,” Brakel said. “A Turkey-supported rebel canton would be harder for the Syrian regime to recapture eventually, so I think Russia would prefer a Kurdish-dominated presence there as well.”

Manbij is the key sticking point to a wider deal

Charles Lister, Senior Fellow and Director of the Extremism and Counterterrorism Program at the Middle East Institute said control of Manbij is the sticking point in a wider U.S.-Turkey deal.

“This operation was something long in the planning for Turkey, so it’s possible that the BSF announcement … catalyzed or accelerated plans for the intervention, but it wasn’t the cause per se,” Lister told The Defense Post.

“Turkey’s objectives here are clear: to at minimum restrict the YPG to northeastern Syria, where it would remain operational under American eyes, and to assert more control over who controls what on the other end of its border with Syria in the northwest,” Lister said.

“As I understand it, there are negotiations underway now between the U.S. and Turkey to come to a grand deal, whereby Ankara permits the U.S. to proceed with the BSF in the northeast in exchange for some extent of U.S. support for a “secure zone” in the northwest, which would encompass at least part of the Afrin district.”

“Manbij at the moment is the key sticking point, as the Turks want it back and the Americans are refusing to consider abandoning it,” Lister said. “I can’t quite see where those talks are going when this is the obstacle in the way.”

US support for Kurds is both moral and strategic

Saying that the announcement of the Syrian BSF simply “supplied the pretext” for Turkey to launch the long-planned Operation Olive Branch, Max Abrahms, Assistant Professor of political science at Northeastern University, believes that an attack on Manbij is a strong possibility.

“I take Turkey at its word that Afrin isn’t the last stop. We should expect Turkey and its Free Syrian Army henchmen to try to mop up other Kurdish areas too, like in Manbij,” he told The Defense Post.

“Leaving aside the moral argument for establishing a Kurdish state, the Kurds have been our main anti-ISIS fighting force on the ground in Syria whereas Turkey has been the biggest state sponsor of ISIS, serving as the jihadi super-highway for foreign fighters to get in and out of Syria, not to mention other Salafi jihadist fighters from al-Qaeda and friends,” Abrahms said. “Supporting the Kurds is not only the moral thing to do, but also strategic.”

“The Kurds are an important check on the kind of radicalism that Turkey has been pushing at all costs in Syria for the sake of regime change. The Kurds deserve more from the U.S. and Russia. And the U.S. and Russia would be wise to stick with the Kurds to limit both Turkish and FSA influence in Syria, which thus far has been ruinous in fighting the terrorists we’re most worried about,” Abrahms said.

Turkey has always prioritized the campaign against Kurds in Syria over fighting ISIS, Abrahms said, adding that with recent significant military defeats of ISIS, Turkey now has more leeway to conduct operations against Kurds.

The US does not fully understand Efrin

CNAS’s Heras agreed that Turkey’s military interventions in Syria are focused on Kurds.

“Operation Olive Branch should be viewed as the second stage of Operation Euphrates Shield, both of which are aimed at cutting the Syrian Kurds down to size,” Heras said. “There should be no misunderstanding here: Operation Olive Branch is meant to rip out the heart of the Syrian Kurdish political and military movement in northwest Syria and to set the stage for a larger campaign against the Syrian Kurds in eastern Syria.”

He said that the U.S. does not fully understand Efrin’s importance to Syria’s Kurds.

“Afrin is a core issue for the Kurdish component of the SDF in a way that the U.S. government agencies that work on Syria have not quite wrapped their heads completely around,” Heras said. “This is a major challenge because the U.S. military is relying on the SDF, and its large Kurdish component, to be the foundation of the Syria border force. The force is key to achieving the stability that the Trump team is trying to achieve with its strategy in Syria.”

Heras said that consequences for the U.S. stabilization effort in Syria could be severe if SDF units are sent from eastern Syria to the west to counter the Turkish operation, adding that a “focused, cohesive, and not-fighting-Turkey Syrian Democratic Force coalition is key to allowing the United States to keep a small footprint approach to its military effort in Syria.”

“If the United States does not act more decisively to stop Operation Olive Branch, there is a real risk that it would ruin the relationship between the U.S. military and the SDF,” he said.

MEI’s Lister similarly says Olive Branch could cause problems for the U.S.-SDF relationship, something that Turkey may have sought to exploit.

“Afrin has huge symbolic value for the PYD and YPG’s cause in Syria, and it’s untouched presence across from the Turkish border was never going to be left alone for ever,” Lister said, adding that Ankara is “more than aware of the sensitive complications” that could and now are resulting from the incursion.

“Self-identified SDF personnel are now redeploying in large numbers from northeast to northwest to defend Afrin, in direct contradiction to everything the U.S. has always insisted about the two corners of the country being qualitatively different. This puts the U.S. in a very difficult position and it also throws a huge spanner into the U.S.-YPG relationship,” he said.

Arguing that Turkey may only want to cut Efrin city off from its support to the east rather than risk an all-out offensive to capture it, Lister highlights a real risk for the U.S. – the prospect of American weaponry turned against its ally Turkey.

“I don’t think the Turks plan to capture Afrin city itself – besieging the city and strangling the YPG’s capabilities would be far more effective from a Turkish perspective,” Lister said.

Potential pitfalls

Looking at the wider picture, Lund pointed out potential pitfalls for Turkey, and potential opportunities for Syrian President Bashar al-Assad and his Russian allies.

“The army-controlled Aleppo road is now the only way in and out of that enclave,” Lund said. “If Assad decides to prop up YPG defenses against the Turks and their allies, he might be able to keep the Kurdish forces alive and frustrate Turkey while also binding Afrin more closely to his regime. Then he can start pulling on those strings.”

Representatives of the Democratic Federation of Northern Syria have said that a deal was put to the Efrin canton administration to allow the Syrian Arab Army into Efrin in exchange for preventing the Turkish operation, and Lund argues that this is likely still an ambition for Russia and Assad.

“Whether they’re acting according to a longer-term plan or just improvising, Russia is probably hoping to turn crisis into opportunity. Their ambition is almost certainly to broker a deal that would let Assad slide back into Afrin, or whatever remains of the enclave once the Turks are done with it. Placing the enclave under his control could serve to both restrain the Kurds from threatening Ankara’s allies and to protect them against Turkey, which may or may not be good enough for both sides – perhaps some fighting will temper their ambitions,” Lund said.

The Heinrich Böll Foundation’s Brakel notes that the SDF and the PYD and YPG have “played international actors against each other quite effectively for the last years.”

“There was always the suspicion that the U.S. and/or Russia might eventually throw them under the bus, which is exactly why they have pursued a strategy of maximising their gains while they still could,” Brakel said, adding that the U.S. reaction to Olive Branch “will definitely not help to build trust among the troops.”

Brakel said he does not foresee direct consequences for western government relations with Turkey, but touched on the issue of arms sales.

“The relationship with Turkey is a difficult one for many NATO states already anyway,” Brakel said. “On a bilateral basis it might affect weapon sales as the operation has triggered in countries such as Germany a public debate, if Germany should continue selling arms such as the Leopard II tank to Turkey, if Turkey continues using it in such operations.”

MEI’s Lister also highlighted the issue. “The YPG’s primary source of military support is the U.S., but Washington simply cannot take the risk of seeing its weaponry being used on the other side of Syria to fight a NATO member,” Lister said.

Meanwhile, Foreign Minister Sigmar Gabriel said Germany has decided to postpone plans to upgrade Turkish Leopard tanks after they were spotted crossing the border into Syria as part of the assault on Efrin, .