The last Martin Marietta LGM-25C Titan II ICBM is taken off strategic alert at Little Rock AFB, Ark. The Titan II had stood nuclear alert since 1963.
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.

