Henri Barkey agrees. “The United States would not mind a Turkish operation into [northern Iraq]. But if [Turkey] also hits [YPG], things would go off the rails.”

“If there is a U.S. redline,” he adds, “that would be it.”

Finally, there is a decent chance that an independent Kurdish state could emerge in Iraq and Syria in the next few years. For years, Ankara and Washington have resisted the idea of an independent Kurdistan. But if Kurdish independence does come to pass, it would be not be in Turkish or U.S. interests to midwife it by killing more Kurds.

Barın Kayaoğlu, an independent political analyst and consultant in Washington, D.C., frequently writes and comments for U.S. and international news outlets. He recently finished his doctorate in history at the University of Virginia. You can follow him on www.barinkayaoglu.com, Twitter (@barinkayaoglu), and Facebook (Barın Kayaoğlu).

Image: Wikimedia/Chris Sang-hwan Jung