Since the terrorist attacks of September 11, 2001, the concept of 'evil' has enjoyed renewed popularity in both international political rhetoric and scholarly writing. World leaders, politicians, and intellectuals have increasingly turned to 'evil' to describe the very worst humanitarian atrocities that continue to mark international affairs. However, precisely what 'evil' actually entails is not well understood. Little consensus exists as to what 'evil' is, how it is manifested in the international sphere, and what we ought to do about it. With this in mind, this work seeks to ascertain precisely what is meant by 'evil' when it is used to describe actors and events in international politics. Focusing on the history of evil in western secular and religious thought, it reintroduces a classical understanding of evil as the means according to which we seek to understand otherwise meaningless human suffering.