The purpose of this book is to appraise the current relevance and validity of realism as an interpretative tool in contemporary International Relations. All chapters of the book are animated by a theoretical effort to define the conceptual aspects of realism and attempt to establish whether the tradition still provides the necessary conceptual tools to scholars. The chapters address important issues in contemporary world politics through the lens of realist theory such as the refugee crisis in Europe and the Middle East; the war against ISIS; the appearance of non-state actors and outlaw agents; the rise of China; cyberwarfare; human rights and humanitarian law. The collection also provides insights on some of the theoretical tenets of classical and structural realism. Overall, the collection shows that, in spite of its many shortcomings, realism still offers a multifaceted understanding of world politics and enlightens the increasing challenges of world politics.