Turkey has long insisted they view the Kurdish YPG and ISIS as basically the same thing. Overnight incidents around the city of Afrin, however, show that when the two forces are in close proximity, the Turkish military is definitely going after the Kurds.
The Kurdish YPG forces were launching an offensive near Afrin against the ISIS fighters when a flurry of Turkish airstrikes were launched against them, described as the single biggest attack Turkey has launched against Kurds since their invasion back in August. Turkish officials estimated 200 Kurds killed.
Turkey has long objected to US support for the Kurds in Syria, and particularly complained about the Kurds taking formerly ISIS-held areas. Afrin is its own sore spot for Turkey, since it is far west of the rest of Syrian Kurdistan, though it has been a Kurdish area since at least the 19th century.
Since Turkey’s August invasion, they’ve demanded the Kurds withdraw from any area west of the Euphrates River, and have also talked of taking full miliitary control of their entire border region with Syria, which would include a large amount of Kurdish territory. So far, they’ve not attempted ground invasions of any Kurdish-held lands, but these airstrikes are a continuation and escalation of the existing hostility toward the Kurds, and suggest the invasion may be only a matter of time.