Near Manbij, Syria (CNN) It's a war America has tried to stay out of for years. And the United States certainly doesn't want to get embroiled in a standoff with a NATO ally.

But in the dust of a front-line outpost outside the Syrian town of Manbij, that is the war that Lt. Gen. Paul Funk, commander of the anti-ISIS coalition, finds himself in as he visits US Special Operations Forces supporting their Syrian Kurdish allies.

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One kilometer (less than a mile) away are Syrian rebels backed by Turkey, which considers the Syrian Kurds around Funk to be terrorists. Turkish President Recep Tayyip Erdogan has demanded that the US Special Operations Forces that Funk commands leave Manbij immediately. But here they remain, their commanding officer giving a handful of media the first access to their highly controversial patrols that have now pitted NATO allies against each other.

An hour before Funk arrived, the nearby Kurdish checkpoint was harassed by Syrian rebel gunfire -- something that happens several times a week. "Any time our soldiers are threatened, that worries me," Funk said. "But that's what they do. ... They will defend themselves."

He agrees that being threatened by a NATO ally is, by definition, "bizarre."

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