Yes, this will hurt the fight against ISIS because the Kurdish militia has been some of the best fighters in the war against ISIS. Who will fight ISIS now? They will need to be replaced quickly so our fight can continue. It is a shame and a tragedy that this happened.
The Kurds are one of the most important elements on the ground in Syria, not only because they have presented themselves as a formidable fighting force against Islamic State and other Islamic fundamentalist soldiers, but because they represent a secular and egalitarian tradition that challenges both Islamic fundamentalism and the tyranny of the state on an ideological level. The loss of these Kurdish militia fighters will be a bitter blow to those seeking to bring the conflict to a just end.
This is a unsettling blow for the people that are trying to fight against ISIS. It is a step backward, but it is not one that the troops fighting to end ISIS cannot recover from. It will prolong the fight, but more troops will come to replace the ones that were lost.
In recent months, much of Turkey's firepower has been directed at the Kurdish separatist PKK in southeastern Turkey and across the border in northern Iraq. It has also occasionally attacked ISIS positions in northern Syria. Turkish tanks entered northern Syria in August in part to help Syrian rebels fight ISIS.