What event/situation is this referring to? I'm not very well informed, could you point me to a source of news you trust?
The Kurds in Syria have been one of the most effective ground forces against ISIS, but their efforts to build an autonomous society along the Syrian/Turkish border have earned them a lot of enemies. Obviously the situation is more complicated than can be explained in a simple comment, and things have been escalating rapidly over the last few days, but look up Rojava if you'd like to learn more. It's a really fascinating story.