The first production version of the RQ-4A Global Hawk UAV rolls out at the Northrop Grumman facility at Palmdale, Calif. (Development versions were used in combat operations in Southwest Asia.)
The U.S. began extensive air and artillery strikes against Islamic State group targets in Syria on Dec. 19 in retaliation for the killing of three Americans on Dec. 13 by a gunman affiliated with ISIS, U.S. officials said.
