Understanding Boko Haram’s expanding reach

Aired: 7/23/2014 | 0:07:29 | Clip
It’s been 100 days since nearly 300 young schoolgirls were abducted by Islamist militants from a town in northeastern Nigeria. Chief foreign affairs correspondent Margaret Warner reports on the growing threat that Boko Haram represents in Nigeria and around the globe, and what’s allowed them to expand their reach.