Wolf Blitzer delivers the most important breaking news and political, international, and national security stories of the day. Tune to The Situation Room weekdays 5-7pm ET on CNN.
Brian Todd examines clues in the video of David Haines' execution. Do British authorities know who the executioner is?
CNN'S Jim Sciutto reports on which countries are joining the effort to battle ISIS and which ones are still hesitant.
Pamela Brown reports that a suspect in a string of killings might have been motivated by strong anti-U.S. sentiments.