The U.S. has vowed revenge after Iran-backed militants fired ballistic missiles towards a base hosting its troops in Iraq. “We are going to respond … to establish deterrence in these situations, and to hold these groups accountable that continue to attack us,” Jon Finer, White House Deputy NSA said. On Jan 21, Islamic Resistance in Iraq targeted U.S. troops at Ain al-Assad air base. The attack led to one Iraqi and possible American casualties. Watch for more details.