The Rise of ISIS

FRONTLINE investigates the miscalculations and mistakes behind the brutal rise of ISIS. Correspondent Martin Smith, who made "Truth, War & Consequences," "Beyond Baghdad," "Private Warriors" and "Gangs of Iraq," reports from Iraq on how the country began coming undone after the American withdrawal and what it means for the U.S. to be fighting there again.FRONTLINE investigates the miscalculations and mistakes behind the brutal rise of ISIS. Correspondent Martin Smith, who made "Truth, War & Consequences," "Beyond Baghdad," "Private Warriors" and "Gangs of Iraq," reports from Iraq on how the...