Seems PKK/PYD/YPG are related, but it still can't justify Erdogan supporting ISIS in the first beginning. I heard lot of Turkey young Kurds crossed the border to Kobani to join YPG fighting against ISIS's intrusion.
I think USA is gonna establish another Israel in the middle east, and you let them have the chance to do that! If Erdogan didn't listen to the bitch Hilary at the first beginning, shit won't happen.
Ambition blinds his eyes.
Erdogan thought he was a player, but later he found out he is only a chess.