If security forces abandon the prisons and refugee camps, thousands of ISIS fighters could be released into Syria and threaten the region and the West, say U.S. military officials.
Syrian Kurdish Asayish security forces inspect tents at the Kurdish-run al-Hol camp on Aug. 28, during a security campaign by the Syrian Democratic Forces against ISIS "sleeper cells" in the camp.
Three U.S. military officials say, however, that patrols with the SDF continued at a reduced rate and without aggressive counter-ISIS missions.
So far, the Syrian rebels and the U.S. military say they have not seen signs of de-escalation from the Turks.
But if Turkish military operations escalate, say U.S. officials, more SDF fighters will move toward the border, leaving detention facilities and refugee camps with inadequate security, say U.S. officials.