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Success on the battlefield can lead to political complications in the many-sided war in Syria. Take the recent military victories by the Syrian Kurds. With the support from the U.S., Kurdish fighters ousted the self-proclaimed Islamic State from a border town and pushed to within 30 miles of the militant's capital city. Now, in Washington, D.C., the U.S.-Kurd alliance is cited as a model to confront ISIS. But another ally - Turkey - fears the Kurds are pushing out ISIS to build a state of their own. NPR's Deborah Amos reports from southern Turkey.
DEBORAH AMOS, BYLINE: It was a remarkable military success just across from this border gate in southern Turkey. In two days, ISIS militants were driven out of Tel Abyad, a Syrian town that straddles this Turkish frontier. A strategic setback for the militants, the border town was a smuggling and a supply route. Kurdish fighters of the YPG, or the People's Protection Units, did the fighting on the ground, allied with Arab rebels backed by coordinated U.S. airstrikes. But now this win for the U.S.-Kurdish alliance has prompted warnings from Turkey and complaints from Syrian Arabs, rebels and refugees, and you can hear it on this border. Activist Ammer Alhamid says he won't go back to Tel Abyad even now that ISIS is gone.
AMMER ALHAMID: Because now Tel Abyad not free.
AMOS: And why isn't it free?
ALHAMID: Because PYD.
AMOS: The Kurdish militia, he says, aims to kick the Arabs out of Tel Abyad and bring in more Kurds - ethnic displacement. That's what Syrian Arabs here believe. Alhamid says that with each victory the Kurds are grabbing land for a Kurdish state. Alhamid says he's fighting for Syrian unity.
ALHAMID: Our project is free for all Syrian people.
AMOS: When Turkey opened the border crossing earlier this week, only a few thousand Syrian Arabs returned home out of the 23,000 who fled to Turkey at the height of the fighting. Hundreds are still camped out at the border, living rough in parks and on concrete patches on the side of the road. They're wary of the Kurds who now control their town. Twenty-five-year-old Fares kisses his mother before she walks through the gate. He refuses to give his full name. He says he was afraid of ISIS when the militants controlled Tel Abyad and now he's afraid of the Kurds.
FARES: (Foreign language spoken).
UNIDENTIFIED INTERPRETER: His family will call him and say came or came not.
AMOS: So come or come not and it depends on if it's safe.
UNIDENTIFIED MAN: (Foreign language spoken).
AMOS: The Kurdish victory has also prompted anger within the wider Syrian opposition and accusations that Kurds forced Arabs out of their homes, a charge the Kurds deny. A human rights team led by Lette Taylor has been looking into those allegations and she says, so far, there's no evidence of ethnic displacement, despite the claims.
LETTE TAYLOR: A lot of Arab refugees we spoke to at the border are telling us that they are scared to go back because they don't know what life will be like under YPG, but many of them are willing to give it a try.
AMOS: Much depends on the next steps. If the Kurds can reassure returning Arab residents, allow local councils to operate again, then international humanitarian aid could restart in the devastated town. But Turkey will also have a say in what comes across the border. The Turks are wary of Kurdish advances on the Turkish frontier, says analyst Thanassis Cambanis, with the Century Foundation. He's currently in the region. The Kurds are under pressure, even as they've become the most effective force fighting ISIS.
THANASSIS CAMBANIS: They absolutely are trying to navigate a very dangerous tightrope between Turkish pressure and American help. And they realize if they go too far in an American-backed campaign, the Turks could make their lives untenable. And at the same time, if they don't protect themselves from ISIS, they could be annihilated.
AMOS: ISIS militants proved this week that they can hit back hard, killing more than 140 Kurdish civilians in the town of Kobane on Thursday. Still, the Kurd's vital role fighting ISIS is a turning point. Long marginalized in Syria, the Kurds are now likely to demand a bigger say in the country's future. Deborah Amos, NPR News in southern Turkey. Transcript provided by NPR, Copyright NPR.