Members of the Syrian Democratic Forces (SDF) liberating Raqqa within the last week were photographed in front of a banner featuring the image of jailed PKK leader Abdullah Ocalan, a Kurdish leader who has been identified as a terrorist by both the United States and Turkey.

Ocalan is recognized as the founder of the PKK, or Kurdistan Workers’ Party, a Kurdish terrorist group that has been responsible for attacks inside Turkey for decades, and a group which the United States has continuously asserted plays no part in the Kurdish YPG forces that make up the SDF.

It’s no secret that Ocalan plays an important role in the political ideology of many Kurdish militant groups, but considering the U.S. has relied heavily on these Kurdish units to clear ISIS from its strongholds across Iraq and Syria, and armed and supported them accordingly, it certainly won’t help the relationship between Ankara and Washington.

Turkey has long insisted that the groups fighting within the SDF are no different than the PKK.

Abdullah Ocalan has been in jail for the last 14 years. He has long been a political activist, starting the PKK in 1978 to advocate for an armed struggle for an independent Kurdish state. He is a prolific writer, having written over 40 books, some of which while he has been in prison.