This book presents a selection of revised and updated papers presented in September 2018 at the International Conference 'Rethinking the Crime of Aggression: International and Interdisciplinary Perspectives', which was held in Marburg, Germany, and hosted by the International Research and Documentation Centre for War Crimes Trials (ICWC). 0In light of the activation of the jurisdiction of the International Criminal Court concerning the crime of aggression, international experts from various disciplines such as law, history, the social sciences, psychology and economics came together to enhance the understanding of this complex and challenging matter and thereby opened a cross-disciplinary dialogue regarding aggressive war and the crime of aggression: a dialogue that not only addresses the historical genesis of the current situation, the content of the new aggression provisions, their implementation in practice and their possible regulatory effects, but also instigates perspectives for investigating future developments and issues.