The US and the Soviet Union sign the Intermediate-Range Nuclear Forces Treaty, agreeing to remove all intermediate-range (620 miles to 3,415 miles) missiles from Europe. The agreement results in the deactivation of six USAF tactical missile wings equipped with Ground-Launched Cruise Missiles (GLCM).
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.
