The U.S. is withdrawing all remaining troops from northern Syria, as President Donald Trump said Sunday it was “very smart… for a change” to not be involved in the fighting sparked by Turkey’s onslaught against the U.S.’s long-time battlefield ally, Kurdish fighters.

Tuesday night, two small Islamic State sleeper cells inside Syria’s Raqqa governorate, which is held by the largely Kurdish Syrian Democratic Forces (SDF), targeted two separate SDF positions in region.

“We have more work to do to keep ISIS from coming back,” the spokesperson for the Kurdish-led forces said. “If America leaves, all will be erased.”