Speaking with US news outlet Axios on 23 November, the commander of the Syrian Democratic Forces (SDF), General Mazloum Kobane Abdi, said the US has a “moral duty” to prevent a Turkish ground offensive targeting the Kurdish militia in northern Syria.

“We believe that President Biden will fulfill his promises and protect the Kurds from ethnic cleansing in the region by the Turks, as he has promised during his presidential campaign,” Mazloum said, before adding that “the US and others have a moral duty to defend the families of these martyrs and the people of this region.”

During his presidential campaign, Joe Biden chastised his predecessor for “abandoning” the SDF in late 2019 by having US troops partially withdraw from Hasakah governorate ahead of Turkey’s ‘Operation Peace Spring.’

“This time the operation will not be limited and there will be chaos all along the border with Turkey,” Mazloum warned, before claiming that Ankara’s current strategy has been to announce a new ground operation, conduct preparations, and then test the reactions of the US and Russia.

In 2015, Washington helped establish an alliance between Kurdish and Arab militias to create the SDF, which would become the main force looking to oust the government in Damascus. The militia’s backbone has been mainly comprised of fighters from the People Protection Units (YPG) – an armed group with close ties to the militant political organization Kurdistan Workers’ Party (PKK).

Since then, the US army has provided the SDF with military training and weapons in exchange for support of its illegal occupation of Syria’s resource-rich northeast region.

The Pentagon claims to have trained up to 100,000 “allied fighters” in Syria, including SDF members. Apart from training, as detailed in the 2018 Pentagon budget, $300 million were designated to support the SDF.

In the same year, the UN Commission of Inquiry accused the SDF of committing human rights violations against civilians and of forcibly conscripting children to join the military service.

The deep ties between Washington and Kurdish militants have raised opposition from NATO member Turkey, which considers both the YPG and the PKK terrorist organizations.

Ankara recently accused the PKK of orchestrating a terror attack in the heart of Istanbul and over the weekend launched operation ‘Claw Sword,’ targeting Kurdish positions in northern Syria and Iraq.

These airstrikes have also hit positions held by the US and Russia, drawing condemnation and warnings from both sides. The Turkish offensive has also resulted in the SDF officially suspending all joint operations with the US army.

Despite their long history of collaboration, the US has on several occasions broken its oath and abandoned Kurdish militias in West Asia to their own fate.

In 1991, the US launched operation ‘Safe Haven‘ in the aftermath of the first Gulf War, with the alleged goal of protecting Kurdish refugees fleeing their homes in northern Iraq. Nonetheless, four years later, the US stepped aside once Turkey invaded the so-called ‘Safe Haven.’

Similarly, in 1975 Washington cut-off military support for Kurdish militia fighting the then-pro-Soviet, anti-Shah Iraqi government. At the time, the late secretary of state Henry Kissinger remarked: ​“Covert action is not missionary work.”

The Obama, Trump, and now Biden governments have struggled to balance their deep ties with the SDF and bilateral relations with Ankara.

On top of it all, the current priority for the US government remains Ukraine. Turkey’s crucial role as an arms supplier to the Ukrainians, and a key mediator between Kiev and Moscow, implies Washington is unlikely to question many of Ankara’s decisions.