Syria Situation Report: May 10 - 18, 2017

Russia, Iran, and Syria redeployed forces to constrain the activities of the U.S. in Eastern Syria. Pro-regime forces reportedly deployed hundreds of fighters along the Damascus - Baghdad Highway in Central Syria at the urging of Russia following several weeks of advances in the area by opposition groups backed by the U.S. and Jordan. The U.S. later conducted an airstrike against a pro-regime convoy advancing against opposition groups at Al-Tanaf on the Syrian-Iraqi Border on May 18. Pro-regime forces also seized the Jirah Airbase in Eastern Aleppo Province from ISIS on May 12. These movements suggest that pro-regime forces intend to insert themselves into the campaigns against ISIS in Ar-Raqqa City and Deir ez-Zour Province - thereby preempting long-term expansion by the U.S. in Eastern Syria. ISW has previously recommended that the U.S. refocus the campaign against ISIS towards Deir ez-Zour Province as a long-term base for operations against both ISIS and the Russo-Iranian Coalition in Syria. 
The U.S. and Turkey likely failed to overcome their strategic divide during a meeting between U.S. President Donald Trump and Turkish President Recep Erdogan on May 16. Trump reiterated his support for Turkey in the “fight against terror groups” including as ISIS and the PKK but did not address his recent decision to directly arm the Syrian Kurdish YPG. Erdogan condemned the decision as an “absolutely unacceptable” measure that presented a “clear and present danger” to Turkey. Erdogan also reiterated his calls for the U.S. to extradite exiled cleric Fethullah Gulen. The White House likely offered greater cooperation with Erdogan against the PKK in Turkey and Northern Iraq to mitigate the risk of an imminent rift with Turkey. These efforts nonetheless remain insufficient to reverse the growing strategic divergence between the U.S. and Turkey. 
This graphic marks the latest installment of our Syria SITREP Map made possible through a partnership between the Institute for the Study of War and Syria Direct. This graphic depicts significant recent developments in the Syrian Civil War. The control of terrain represented on the graphic is accurate as of May 10, 2017.