U.S.-backed forces concerned ISIS could regroup in Syria

As the new Syrian authority establishes itself, U.S.-backed forces in the region are concerned about ISIS potentially regrouping. CBS News senior foreign correspondent Holly Williams reports.

U.S.-backed forces concerned ISIS could regroup in Syria
As the new Syrian authority establishes itself, U.S.-backed forces in the region are concerned about ISIS potentially regrouping. CBS News senior foreign correspondent Holly Williams reports.