What's Behind the Resurgence of al-Shabab?

The al-Qaida linked militant group al-Shabab has struck at the heart of the Somali government with a string of attacks in Mogadishu. Long thought to be on the defensive, the recent strikes and a fresh recruitment drive point to a resurgence of one of Africa's most feared terrorist groups. East Africa correspondent Gabe Joselow has the story.