Why did political Islam so readily occupy the position of enemy 'other' for the United States in the context of what the American political leadership of the time labelled the 'War on Terror'? In a wide-ranging analysis of the historical and ideological roots of U.S. discourse on political Islam, Corinna Mullin examines the ways in which this new 'other' came to perform both an identity-constructing role for Americans and a politically expedient, rhetorical justification for mainstream U.S. political thought and action concerning the Muslim world. After a new U.S. administration under President Barack Obama was inaugurated in 2009, Mullin explores the prospects for a truly 'post-war on terror' politics.