On Sunday, a suicide bomber killed at least 42 people in Iran, including five senior commanders of the powerful Revolutionary Guard. The Sunni guerilla group Jundallah, or 'Soldiers of God,' claimed responsibility for the attack.  This was the deadliest attack against this elite unit since a bombing in February 2007, which was also claimed by the same group. Despite Jundallah's claims, Iran is blaming the United States for the attacks. We dig into this accusation with Professor Hamid Dabashi, professor of Iranian Studies at Columbia University.