Five days ago, the predictions came true. Free Syrian Army units in the city of Der al Zour handed over their territory to the Islamic State of Iraq and al Sham, following weeks of desperate requests for help to international officials, including a direct appeal in a private meeting with U.S. Ambassador to the United Nations Samantha Power.

“[The U.S. officials] showed an understanding of the situation but there was no movement at all,” the commander of the FSA battalion near Der al Zour told The Daily Beast in an interview. “There’s no clear American position in that part of Syria. We told the Americans we are going to fight ISIS and ISIS is close to us, but they did nothing.”

Two leaders of the Free Syrian Army in eastern Syria told The Daily Beast that the moderate rebels in the area greatly outnumbered the ISIS fighters returning from Iraq in stolen American-made vehicles. But the FSA battalion, weakened from months of being under siege, did not have enough ammunition to engage ISIS in the fight. They retreated south, giving up what they controlled of Der al Zour to ISIS without ISIS having to fire a shot.