How terrorists exploit Europe's divided intelligence efforts

Aired: 11/19/2015 | 0:08:14 | Clip
French authorities say the ringleader of the Paris attacks was killed in a raid outside Paris on Wednesday. So how did he return to Europe undetected after joining the Islamic State in Syria? Lorenzo Vidino of George Washington University and Stacy Meichtry of The Wall Street Journal join Gwen Ifill to discuss.