Few works can claim to form the foundation stones of one entire academic discipline, let alone two, but Thucydides's celebrated History of the Peloponnesian War is not only one of the first great works of history, but also the departure point from which the modern discipline of international relations has been built. This is the case largely because the author is a master of analysis; setting out with the aim of giving a clear, well-reasoned account of one of the seminal events of the age – a war that resulted in the collapse of Athenian power and the rise of Sparta –...