The Syrian Kurds have asked Syria to help them because Turkey is threatening them. President Erdogan treats them as an extension of the Kurds in Turkey who want independence from Turkey. During the main part of the war in Syria (which seems to be tailing off now) the Kurds fought the Takfiri rebels. The United States, which supplied a lot of the so-called rebels including ISIS (indirectly at least) at times appeared to support Kurdish independence, using them as a lever against the Syrian Government. The Kurds had been offered control of their own department by the Syrian Government, but not actual independent state status. The US rewarded a Kurdish independence movement against Syria, although it is not clear that all Kurds in Syria really wanted this. The region also contains substantial minorities of Arabs and others whom a separate Kurdish state might not have suited. Until Russia intervened in the war (at the invitation of the Syrian Government) it looked like the United States backed terrorists were going to tear the country apart. The UN and NATO and its allies, including Australia, all supported this with a policy of removing President Assad and splitting Syria into many little states. The western public and corporate media provided propaganda to support this.