It's an interesting point though because US presence would have a 'calming' influence over the YPG and if anything that would give Turkey a chance for a political settlement (not that they are interested). Of course when the US pull out that calming and civilising influence is gone the moment the Turkish tanks roll over the border and start blasting.
Then the YPG is likely to make counter-strikes on Turkish soil and then Erdogan will be happily be pointing and shouting 'Terrorists!' from the rooftops again.
