The terrorist attacks of September 11, 2001, and the subsequent US-led invasions of Afghanistan in 2001 and Iraq in 2003 profoundly affected all aspects of society, including cinema. Or did they? Even now, years after those horrific events, debate still rages over their impact on films. At the time many expected Hollywood to tamp down graphic movie violence, while others hoped that filmmakers would finally lay bare volatile socio-political issues fuelling terrorist attacks. In fact, what has emerged is a thicket of darkly pessimistic genres including thrillers, combat films, sci-fi, and horror that makes pre-9/11 films appear naive and optimistic. Hollywood 9/11 explores this transformation, critically examining everything from Harry Potter and the Half-Blood Prince to The Hurt Locker and placing the films in the context of both the socio-political scene and the history of cinema.