What drove a small sect to take control of Yemen?

Aired: 4/7/2015 | 0:07:04 | Clip
The U.S. will speed up delivery of arms and intelligence to Saudi Arabia for the fight against Yemen’s Houthi rebels, according to the State Department. How did the Houthis rise to stage a government coup? Gwen Ifill learns more from journalist Safa al-Ahmad, who offers a rare inside look in a new documentary on Frontline.