How the ISIS attack on Iran may escalate regional conflict

Gunmen stormed Iran's parliament building Wednesday morning, igniting a siege that lasted for hours, killing 13. Meanwhile, the shrine of the Ayatollah Khomeini was also attacked. Chief foreign affairs correspondent Margaret Warner reports, and William Brangham speaks with Randa Slim of the Middle East Institute and Karim Sadjadpour of the Carnegie Endowment for International Peace.