The emergence of Thucydides as an influential political thinker in the first half of the 20th century has been astonishingly neglected by modern scholars. This volume examines how, why, and when the Athenian historical came to occupy such a prominent position in political discourse in the US and Europe today. It argues that in the years before, during, and after the Great War Thucydides History of the Peloponnesian War was mined for the insights that it could offer into contemporary politics, and that it was also used as part of the justification for the academic and cultural relevance of Classics at this time of great political upheaval.