Stahl's book is widely recognized as one of the defining studies of Thucydides from the 20th century. Here in English for the first time, it penetrates as few others to the Greek writer's deepest interests. Stahl reveals Thucydides' work as a study in the fallibility of human projects. Above all, Thucydides is shown as interested in tracking how optomistic plans lead to irremediable suffering in the field of foreign policy. For this new edition, the original has been revised and enlarged by two chapters which reflect the author's subsequent work.