The US is walking a fine line between competing allies, as Turkey increases its threats against the Syrian Democratic Forces.
Turkey has ramped up strikes on Kurdish groups in Syria and has threatened to carry out a ground invasion following a bombing in Istanbul earlier this month.
Ankara blamed the attack on Kurdish militias, including the US-backed SDF. The group has denied involvement.
The US Department of Defence said on Tuesday that its mission to defeat ISIS continues in Syria, but the SDF has reduced the number of partnered patrols it typically conducts with American troops amid increased threats from Turkey in recent weeks.
A US State Department representative told The National that it has emphasised to Turkey that military escalation “will not resolve” its security concerns.
Meanwhile, SDF chief Mazloum Abdi demanded “stronger” support from US partners on Tuesday after an unprecedented Turkish troop deployment on the Syrian border.
Officials in Ankara have warned they would need only days “to become almost fully ready” to carry out a ground incursion into Syria's north-east.
“The Biden administration is stuck between a rock and a hard place,” Charles Lister, senior fellow at the Middle East Institute in Washington, told The National.
“I’m not surprised [they have] taken to walking on eggshells, as that’s its only option frankly.
“Of course we want to avoid a Turkish incursion … but US troops are never going to face off against Turkish soldiers — that’s just not on the cards.”
Jonathan Lord, senior fellow and director of the Middle East Security Programme at the Centre for a New American Security, argued that Washington's cautious tone is “almost permissive” of Turkish escalation, and it is clear that the US is “picking its battles”.
“The primary objective is to cajole Turkey to be a good ally in Europe and support US efforts in Ukraine and Nato accession for Finland and Sweden,” Mr Lord told The National.
“As long as Turkey doesn’t do damage to US interests, they have a green light.”
But he added: “The very nature of the [Turkish] operation is undermining US interests and further destabilising the region.”
The Turkish bombardments come after months of ground invasion threats from Turkish President Recep Tayyip Erdogan, who considers the SDF to be terrorists. This rhetoric has only intensified since the Istanbul bombing.
National Security Council spokesman John Kirby told reporters on Monday that Washington was “not in a position to say who was responsible” for the bombing in Istanbul and that the White House “did not want to see any actions within Syria”.
Nicholas Heras, director of strategy and innovation at the New Lines Institute, told The National that Ankara is applying “maximum pressure” on Washington to leave north-east Syria — and leave responsibility for Kurdish forces “to some combination” of Turkish, Russian and Syrian government forces.
Bob Menendez, the leading senator on the Foreign Relations Committee, last week called Ankara out over the strikes, claiming the attacks on US partnered forces “are not the actions of an ally”.
Otherwise, there has been relative silence in Congress on the increased tension between two of Washington's critical regional allies.
One of Turkey's targets in Syria has been US-backed forces guarding Al Hol detention camp, a facility holding suspected family members of ISIS fighters, as well as civilian infrastructure.
The threat of a Turkish ground operation poses the risk of diverting SDF resources away from the anti-ISIS mission, particularly its control over Al Hol and anti-radicalisation efforts there.
“Escalation threatens both humanitarian efforts in the area and the safe repatriation of these vulnerable individuals to their countries or areas of origin,” a State Department representative told The National.
Last week, US Central Command (Centcom) urged the repatriation of the detainment camp's international residents after officials reported the discovery of two beheaded Egyptian girls.
For Mr Lister, these types of dilemmas were an “inevitable consequence” of Washington's decision to join forces with the Kurdish YPG in its mission to counter ISIS in Syria.
“Whether that decision was the right one is unimportant at this point … we can only hope that wiser heads prevail and Turkey’s campaign avoids a ground component, but with elections just months away, these are worrying times,” Mr Lister added.
Natasha Hall, senior fellow at Washington's Centre for Strategic International Studies, said the instability highlights the consequences of the continued US pivot away from the Middle East after years of entrenchment.
“Lack of consistent, high-level diplomacy can curb the US ability to prevent crises, which profoundly affects trust in the US amongst allies and, therefore, the US ability to shape events,” Ms Hall told The National.