As autocratic and intemperate as he is, Erdogan isn’t actually wrong about the commingling of various Kurdish outfits. In a 2013 interview with Osman Ocalan, the brother of imprisoned PKK leader Abdallah Ocalan, Osman claimed that he and other PKK figures founded the Democratic Union Party (PYD), the YPG’s political arm, in 2003 in Iraq’s Qandil Mountains, the headquarters of the PKK. The PYD is also a member of the Kurdish Communities Union, established in 2005 in Qandil by the Kurdish People’s Congress, a PKK organization that the State Department added to the FTO in January 2004. The co-chairperson of the executive council of the Kurdish Communities Union is Cemil Baylik, the acting leader of the PKK. In addition, hardened PKK activists, fighters, and commanders fill the ranks of the PYD and YPG. A YPG fighter told The Wall Street Journal that he had been with the PKK before, and that fighters regularly rotated between PKK armed entities. Iraqi Kurdish Region President Masud Barzani, a close ally of the United States against ISIS, said in March 2016 that the PYD and the PKK are basically the same entity.

Yet, the Trump administration (and Obama’s before him) keep contending, as recently as March 8, that the PYD-YPG and PKK are separate entities. But this has no basis in observable fact. And given the organic links between the YPG and the PKK, the PYD-YPG autonomous zone in northeastern Syria will likely provide strategic depth for the PKK’s ongoing and future fight against Turkey—something Erdogan knows and fears. There are reports out of Turkey already that Kurdish militants aligned with the PKK and PYD organized and trained in YPG-held northeastern Syria for attacks conducted in Istanbul, Ankara, and Bursa, in 2016.

By relying on the YPG in the fight against ISIS, the United States is helping one terror group fight against another. That’s despite its longstanding policy of not working with any organization on the FTO, as it is doing with the YPG, which is effectively synonymous with the PKK. Of course, some argue that the PKK should not be on the U.S. FTO list. An in-depth discussion on the conditions for the PKK’s removal would require months. In the meantime, however, blatantly ignoring the FTO strictures on official U.S. conduct with a listed organization like the PKK and its subsidiaries reflects utter policy incoherence, diminishing America’s credibility on fighting terrorism.

America’s infatuation with the PYD-YPG also allows it to ignore some uncomfortable realities that will haunt it long after ISIS is ousted from Raqqa. While the PYD-YPG organization is secular, it is not democratic. It has repressed political competitors, detained other Kurdish political activists, and detained and harassed independent journalists. What’s more, its emphasis on gender equality, and its insistence on imposing its political agenda, will cause problems for the future governance of Raqqa, the de facto capital of ISIS, and other Arab-majority towns the United States is now helping it seize from a weakened ISIS.