which is drawn from syrian kurds, is linked to the pkk, the kurdistan worker's party in turkey. syrian opposition fighters know that alliances could be shifting. >> we are being stabbed in the back in the northern countryside where the pkk and it's allies took advantage of the fact we were fighting to two fronts. >> a new front has been opened in an already complicated war. >> turkey's policy in syria has been clear from the beginning. it want regime change in syria and to present a kurdish state from being created along its border. it wants a safe zone along the syrian side of the border to serve as a before to protect the interests. so far, the international community has not accepted that demand. turkey's latest actions serve as a message that it will stand by its red line. >> for the government, one of the lines is azez, a rebel-controlled town a few kilometers from the border. it is home to tens of thousands of displaced syrians.