This book examines how social media has transformed extremist discourse. It looks at how ISIS by a sophisticated use of social media platforms and PR concepts was able to recruit, mobilize and spread fundamentalist propaganda in regions where it had little physical presence. The volume focuses on the inadequate response of the international community and the possibility of a more comprehensive approach from a Public Relations and Strategic Communication viewpoint. It demonstrates how Public Relations practice can be successfully and meaningfully used in counter-extremism activities. One of the first studies to draw a link between international diplomacy, the rise of fundamentalism and public relations, this book will be of great interest to scholars and researchers of defence and strategic studies, especially those working on ISIS, Middle East Studies, media studies, digital humanities, communication studies, public relations, international relations, as well general readers.