YPG has a different agenda and everybody knows this. And albeit costly, ISIS actually gave them an opportunity. They just want to close the northern border of S

YPG has a different agenda and everybody knows this. And albeit costly, ISIS actually gave them an opportunity. They just want to close the northern border of Syria for their liking. Just do not assume they are peaceful (http://www.al-monitor.com/pulse/originals/2015/10/syria-turkey-right-groups-accused-kurds-rojava-of-war-crimes.html http://www.al-monitor.com/pulse/originals/2015/10/syria-turk...) Turkey wants a protected zone to repel ISIS from Turkish border and YPG closing the north line. That's about it. YPG has plenty of open space to fight ISIS if they want to. Do not overestimate YPG. Without US support, they probably would have lost the game long ago.