The United States’ reaction to the Turkish air campaign in Syria, following the November terror attack in Istanbul, was very lenient. Many observers initially interpreted it as an American green light, at least for a limited military operation. This ambivalent position created some question marks regarding the future of the Türkiye-US relations, especially considering the consistent negative trajectory witnessed in the past few of years, hitting rock bottom during the Brunson crisis when former president Donald Trump threatened Ankara with economical destruction unless Pastor Brunson, who was under arrest in Türkiye due to missionary related charges, was released.

There are many issues in the US-TR relationship that are, to say the least, problematic. For instance, Fetullah Gulen, a cleric and the leader of the Gulen Movement, which is considered to be the perpetrator of the 2016 failed coup by an overwhelming majority of Turkish society, still resides in the US. Turkish foreign policy in the Eastern Mediterranean, which is dubbed as assertive by many Western nations, is also a source of friction that periodically creates tensions between Ankara and Washington.

However, the main issue that poisons the relationship between two NATO allies remains their respective irreconcilable positions on Syria, and more specifically Democratic Union Party (PYD), the Syrian offshoot of the Kurdistan Workers’ Party (PKK). The remaining disagreements can possibly be compartmentalized and managed, whereas the friction caused by the issue of PYD and its military wing the People's Protection Units (YPG) over the years has proved to be too fundamental, at least for Ankara, to overlook or compromise.

The roots of this seemingly intractable conflict between the US and Türkiye can be traced back to the Syrian Civil War. At the peak of the rebellion in 2012 the regime’s security apparatus was stretched too thin and President Bashar al-Assad withdrew its forces from northeastern Syria in order to consolidate security resources. To prevent the rebels from filling the power vacuum due to the withdrawal, the regime handed over the said territories to PYD/YPG, which was perceived as an actor that can be cooperated with due to the regime’s long standing relationship with PKK as well as PYD/YPG’s non-alignment with rest of the rebellious factions. Thus, when the regime withdrew from Northeast Syria, YPG/PYD began governing mostly in Kurdish inhabited territories such as Afrin and Kobani as well as a few provinces where Kurdish people did not make up the majority, such as Hasaka province.

The campaign that ISIS launched against YPG/PYD in 2014, which ultimately resulted in the defeat of the “Caliphate” by YPG forces with the support of Iraqi Kurdish Peshmerga and US airpower, “for four months, coalition aircraft rained munitions on ISIS positions, bolstering the Kurdish defenders and inflicting hundreds of casualties. American B–1B Lancers routinely expended their entire ammunition payloads during sorties. Coalition C–130 Hercules cargo planes also airdropped tons of supplies to the YPG.” This campaign had overarching implications for the conflict and the broader region. YPG/PYD further solidified its authority over Kurdish majority areas in Northeast Syria. As the war against ISIS raged on, the YPG/PYD control further expanded to Arab majority areas to the east of Euphrates and the US found a reliable partner/ proxy on the ground to battle ISIS remnants. On the other hand, Türkiye’s Syria policy started gradually shifting from toppling the Syrian government to preventing the creation of a PKK-linked, US backed autonomous entity along its southern border. To that end, Türkiye launched three cross border military operations, The Operation Euphrates Shield in August 2016, The Operation Olive Branch in January 2018 and The Operation Peace Spring in October 2019, which further deteriorated the relationships between Türkiye and its Western allies.

The organic ties between YPG/PYD and PKK was never really a secret. In 2015, Zind Ruken, a PKK militant, said during an interview with the Wall Street Journal, “Sometimes I’m a PKK, sometimes I’m a PJAK [the PKK-allied affiliate, active in Iran], sometimes I’m a YPG. It doesn’t really matter. They are all members of the PKK.” Moreover, an Atlantic Council study showed that Turkish citizen Kurds made up approximately half of the casualties reported by YPG between 2013 and 2016. Clearly, the US was aware of this relationship yet, at the expense of alienating a NATO ally, the US chose to partner with YPG/PYD to combat ISIS. Multiple factors that are not necessarily mutually exclusive can explain the path American foreign policy pursued in Syria.

The initial American engagement with YPG/PYD coincides with “The Solution Process” of 2013-2015, which was a period of direct peace negotiations between Türkiye and PKK, thus Türkiye’s approach towards YPG/PYD was relatively conciliatory. Former PYD co-chair Salih Muslim’s visit to Ankara back in 2014 crystalizes that. It can be argued that perhaps the US was over-confident regarding the Solution Process, and the relevant agencies in Washington did not see any harm in making a fundamental policy decision based on the potential success of a fragile peace process in ending a 40-year-old insurgency. A more likely reading would be that American policymakers at the time saw Türkiye’s peace process with PKK as a window of opportunity to engage with YPG/PYD and the implications of such a rapprochement on the ongoing peace process was of a secondary importance. Thus, once the negotiations collapsed and Türkiye - PKK subsequently resumed fighting, the US found itself in a very difficult but predictable position. Since then, the US has been trying to manage this crisis by on the one hand ensuring Ankara that the partnership with YPG/PYD is purely transactional as well as by turning a blind eye to limited Turkish incursions into Syria, and on the other by providing YPG/PYD with enough security guarantees that the war against ISIS continued. The US reaction to the recent escalation can be read in this vein. Following the 13 November 2022 Istanbul bomb attack, holding PKK and YPG/PYD responsible, Türkiye launched an intensive air campaign and strikes targets in Syria & Northern Iraq with around 25 air raids, killing at least 31 YPG fighters.  The American response to this was just a broad call for de-escalation. The US only gave a strong reaction when Ankara stated its intention to conduct a new cross-border operation.

It is clear that the US is willing to accommodate strained ties with a NATO ally in order to preserve, what is claimed to be, a purely transactional relationship with a non-state armed group. Given that Washington’s statements regarding the nature of its partnership with YPG/PYD are true, there are a couple factors that might explain the US’s desire to maintain a delicate balance between Türkiye and YPG/PYD. The most apparent, as well as the official reason, is to perpetuate the battle against ISIS. Although the so-called caliphate has been dismantled, ISIS cells still exist, particularly in Eastern Syria. Moreover, tens of thousands of ISIS militants and their families are still being held in camps under the auspices of YPG/PYD which increases the utility of the non-state armed group in the eyes of American policy makers.

The second factor that makes the partnership with YPG/PYD invaluable is the pretext it provides for US military presence to remain in Syria. It is not a secret that one of the primary policy goals of the US, not just in Syria but in the broader Middle East, is to diminish Iranian influence and in doing so, severing the land connection between Iran and Hezbollah. The persisting American pressure via the Caesar Act as well as the American military presence at the Jordanian border, where ISIS cells do not really constitute a threat, demonstrate that. Until now, the US has derived both the internal and the external legitimacy of its Syrian campaign from fighting against ISIS, and YPG/PYD become an actor but more importantly, the symbol of that endeavor. Thus, ending the partnership with YPG/PYD would cost the US more than just feet on the ground, it would make the American mission in Syria extremely challenging for American policymakers to defend in the public forum. 

Ankara is well aware of the co-dependent nature of the US - YPG/PYD relationship. Time and time again Türkiye has publicly urged its NATO ally to partner with them instead of YPG/PYD in the war against ISIS. On paper, this would be a tempting proposal for American policymakers. Resources and capabilities Türkiye could bring to the table in the war against ISIS would alleviate a significant burden from the US’s shoulders. Moreover, beyond keeping ISIS activities in check, US-backed Turkish presence in Eastern Syria could exert immense pressure on Damascus as well as Iran-backed militias in Syria. Yet, this proposal has not been accepted by the US, mostly due to the brewing confidence crisis between the two allies, which is an amalgamation of institutional conflicts and the perceived divergence of geopolitical interests.

It is difficult to predict the future of the Türkiye - US relationship, especially in the wake of the presidential elections in Türkiye. It is highly likely that, in the short to medium term, the status quo will be preserved. The US will continue to work with YPG/PYD in Syria, which will continue to cause resentments in Ankara. However, there is a shifting dynamic that needs to be noted. The MENA region’s importance in the eyes of the American policymakers has been gradually declining in the past few years. The war in Ukraine has accelerated this shift and revitalized the issue of European security and the role of NATO for Washington. Furthermore, this regional re-adjustment in national security priorities will have overarching implications. Over time, it can be expected that EUCOM, which has traditionally enjoyed a close partnership with the Turkish Armed Forces via NATO, will be the dominant command in the Pentagon, by replacing CENTCOM, which has been skeptical about Türkiye’s value as an ally ever since Turkish parliament rejected a proposal to allow US troops to operate from Turkish soil and open a northern front in the war with Iraq. Thus, in the long term, the number of American decision makers, who consider the partnership with YPG/PYD as a liability, may surpass those who consider it as an asset.