The backstory behind those controversial photos of US troops fighting ISIS in Syria
The photos, taken by Delil Souleiman for Agence France-Presse, have also enraged Turkey and reignited the debate over Washington's support for the YPG, with some calling the patches "politically tone deaf" and others insisting it is "perfectly normal."
In a blog post for AFP, Souleiman described the photos as the product of a "chance encounter" in the northern Syrian village of Fatisah, which had just been captured from ISIS by the US-backed, YPG-dominated Syrian Democratic Forces (SDF).
"Armed with machine guns and rocket-propelled grenades, the strangers pulled up in pick-up trucks," Souleiman wrote. "They stood out right away. Most didn't look like they came from the region and they spoke English between them, with that distinctive Yankee drawl. A dead giveaway."
About 250 US special-operations troops were sent to northern Syria earlier this year to advise Kurdish and Arab forces battling ISIS there. The US has insisted that the forces are not on the frontlines, but Souleiman's photos and recollection of the incident seem to contradict that assertion.
The US soldiers have "never been photographed in Syria before," Souleiman wrote. "And here I was, actually seeing them in the flesh and near the frontline."
He continued: "They don't prevent me from taking pictures. They don't seem to think that a photographer here is something bizarre. Some have a patch of them American flag on their sleeves. Others have the patch of a Kurdish People's Defence Units (YPG). Still others of a women's unit within the YPG. I wonder why, but don't dare to go up and ask."
Souleiman went on to describe how comfortable the US soldiers seemed to be with having their photos taken, though they requested that the photos not show their faces. He recalled passing another group of US forces on his way to a training camp outside Fatisah, which is about 30 miles north of ISIS' de-facto capital, Raqqa.
The SDF began its offensive on Raqqa earlier this week, evidently with the close help of US special-operations forces.
The YPG has proved to be the most effective ground force fighting ISIS, but the territorial expansion the YPG's victories have afforded it is vehemently opposed by Turkey, an important US ally and NATO member.
Indeed, the photos have enraged Turkey's foreign minister, who on Friday called them "unacceptable."
"It is unacceptable that an ally country is using the YPG insignia," the foreign minister, Mevlut Cavusoglu, said, according to the Turkish daily newspaper Hurriyet. "We reacted to it. It is impossible to accept it. This is a double standard and hypocrisy."
Pentagon spokesman Peter Cook told reporters in a press briefing on Thursday that the "special-operations forces, when they operate in certain areas, do what they can to blend in with the community to enhance their own protection, their own security."
He would not comment on the specific photos but added that the troops were most likely just being "supportive of that local force [YPG] in their advice and assist role."