Defense Secretary Mark Esper refused to put a timeline on the Pentagon’s scaled-down mission to defeat the Islamic State and guard Syrian oil fields at the agency’s last press briefing of the year.
Conditions-based: "That's a crystal ball that I don't have,” Esper responded when asked when 600 US troops in the war-torn country would leave. “I think we're there as long as we can ensure the enduring defeat of ISIS."