Runaway Girls: Who Is to Blame When Teens Join ISIS?

They were "smiling," a shell-shocked Turkish worker told the families of three London schoolgirls as he begged forgiveness for his chance role in their disappearance in Syria. The middle-aged bus station employee, who was spotted on surveillance video holding open a door for the girls as they headed for the Syrian border, had a chance encounter with their tearful families who had come to Istanbul to search for them. Halima Khanom, the sister of missing Kadiza Sultana sobbed, "We don't blame you." But who exactly should be blamed for the radicalization of Sultana, 16, and Shamima Begum and Amira Abase, both 15, and their subsequent trek across Europe to reach the ISIS' "caliphate" has prompted a bout of debate and blame-trading in the U.K.