The Sunni extremist group the Islamic State in Iraq and Syria (ISIS) has waged a violent campaign in recent months, capturing large areas of territory in both countries. In June, the group declared itself a new Islamist caliphate, or formal Islamic state, and proclaimed leader Abu Bakr al-Baghdadi as the caliph. Experts worry about what the rise of the Jihadist group will mean for the future of Iraq, for the stability of the region, and for United States security.