The US and Turkey began joint military patrols in northeast Syria along the Turkish border, a possible sign that the US is trying to cater to Ankara’s demands regarding the future of eastern Syria. The patrols, which saw Turkish military vehicles and US military vehicles, each with their country’s large flags attached, driving around dry farmland, come after a year of Ankara’s threats to launch an attack on eastern Syria against US partner forces.According to reports the US said that the patrols are part of the “security mechanism” that was announced last month amid renewed Turkish threats. The patrols are one part of a mechanism that has seen the Kurdish People’s Protection Units (YPG) uproot fortifications near the border and claims to illustrate that the YPG has left an area of eastern Syria along the border. The complex backstory to this is that in 2014 ISIS attacked this area and threatened to exterminate and ethnically cleanse Kurds, minorities and anyone who didn’t adhere to the ISIS extremist interpretation of Islam. Instead ISIS was met with resistance from the mostly Kurdish YPG who eventually were able to push them back with the help of US and coalition airstrikes. Later, with more assistance from special forces and light arms, the YPG and the Syrian Democratic Forces helped liberate Raqqa and defeat ISIS in eastern Syria. But for Turkey this was problematic because Turkey claims the YPG is part of the Kurdistan Workers Party (PKK) which Turkey had fought a war with after a ceasefire broke down in 2015. Turkey invaded Afrin in northwest Syria in January 2018 to defeat the YPG and has said it intends to do the same thing to eastern Syria. In Afrin more than 150,000 Kurds were displaced by fighting and hundreds of thousands of mostly Arab Syrian refugees settled in Afrin, changing the demographics of this historic Kurdish area. Turkey says it will return eastern Syria to its “true owners” and has said it wants to send a million Syrians, most of whom are not from eastern Syria, to move into eastern Syria in a “safe zone” that Turkey has demanded control over.The US, which is partnered with the SDF and wants to see ISIS fully defeated, has objected to Turkey’s plans for a military operation, concerned it will destabilize eastern Syria at this unique time when the area requires peace and prosperity. When Turkey announced plans for a similar military offensive in Manbij the US came up with a concept of joint military patrols. But Turkey has said that it will not accept a Manbij-style solution to areas along the border. So it has demanded that its forces be allowed into Syria, which the US appears to have facilitated in order to avoid a possible Turkish offensive. Last month Turkey said it had informed the US and Russia that an offensive would take place and only last minute discussions with US military officials supposedly stopped the operation. Since then Turkey has gone to Russia to propose buying more Russian military equipment, has threatened to build nuclear weapons and threatened to “open the gates” of refugees going to Europe if its demands are not met in eastern Syria. It’s unclear if Ankara’s threats are just talk designed to see if the US will budge, or if it would actually launch an offensive in an area where US forces are present.Washington is in a difficult place because Turkey is ostensibly a NATO ally and Washington has paid lip service to caring about Turkey’s concerns, while some wonder what Turkey’s real goal is. Turkey has acquired Russia’s S-400 missile defense system and seems to want to play the US and Russia off against one another, while Ankara claims it has been betrayed by the US which it accuses of training a “terrorist army” in eastern Syria. But for the US the SDF and mostly Kurdish forces on the ground have proven capable partners defeating ISIS.The joint patrol that took place on September 8 leaves many questions. No one seems to agree exactly how far these patrols will extend. According to CNN’s Ryan Browne they could go as deep as 5-12km into Syria. The patrols are also complex because they involve not just US-Turkey cooperation at the three-star general level, according to recent comments by Chairman of the Joint Chiefs Gen. Joe Dunford, but they also involve cooperation between US European Command and Central Command (CENTCOM). European Command is eager to show that these patrols go well and work closely with NATO ally Turkey. So it tweeted about how the US and Turkey had conducted the patrol “inside the security mechanism” on September 8. It followed an announcement over the weekend by European Command about US Black Hawk helicopters conducting an aerial patrol over northeast Syria with Turkish military helicopters alongside.The patrols were photographed on the ground by locals near the area between Tel Abyad and Ras Al-Ain. SDF General Mazloum Kobani told CNN over the weekend that he is concerned about the prospect of a Turkish military offensive. Mazloum agreed to a safe zone and says his forces have shown flexibility. He is confident the Americans are going to be responsive. The SDF seems to be doing everything it can to make sure the US is pleased. This is because the US had threatened to leave eastern Syria last December which would have left the SDF exposed to a Turkish offensive and a repeat of what happened in Afrin. The SDF has said it removed fortifications that the Coalition forces surveyed on September 3. On the ground on September 7, in the lead up to the patrols, Coalition aircraft could be head and vehicles were present, locals said. The patrols began at 10am and were one of several that are supposed to take place between Tel Abyad and Sere Keniye (Ras al-Ayn).The SDF have sought to change the forces they deploy on the ground as part of making the security mechanism work. This included the participation of the Tel Abyad Military Council and the Sere Kaniya Military Council. The latter has some 300 locals that were trained for securing the area, according to the Rojava Information Center.The joint patrols differ from the US-Turkey joint patrols that began last year near Manbij. There the patrols went along a line outside the city, but there are questions about where these patrols will go and the fact that the Turkish army is now operating inside northeast Syria. There are concerns that once Turkey begins operating there, it may not be willing to leave and this may presage more demands. It’s unclear how the US will respond to those demands. It also appears that despite the efforts devoted to defeating ISIS that a tremendous amount of time and resources are going in to make sure these patrols work, but how they will satisfy both Turkey and the SDF and people on the ground is unclear. If the SDF senses that this is just way for Turkey to inspect the area and reduce fortifications in order to pave the way for an eventual land grab there will be a crises. Turkey has already become an expert in provoking crises with the US in order to get the process moving. This is a linear process for Ankara that began with Euphrates Shield in 2016 when Turkey and its Syrian rebel allies took over an area of northern Syria between Jarabulus and Kilis. It extended to the Afrin operation in January 2018 and Turkey’s observation points in Idlib. This is leading toward Turkey’s fourth major demand in Syria in an ever-expanding military and civilian role. The joint patrols matter because they may have given Turkey an entrée into more demands in eastern Syria, but they could also prove to be a US solution to Turkey’s demands so that Ankara can say it got its safe zone. That all depends on Turkey’s next move.