Opinion | The Lesson History Teaches Is Tragic

Is it possible that the real trap, though, is the still widely unquestioned assumption that Thucydides was a political realist? That if he does offer lessons, they are not found in the study of international relations but in the study of human nature? That his brand of realism has little to do with the work of modern political theorists and much to do with the work of ancient tragedians?

Consider the story Thucydides writes about the Peloponnesian War, one he insists was even more momentous than the Persian Wars. Thucydides does not explain this outwardly outrageous claim because he does not need to: As his readers understood, this new war did not pit Greece against a foreign foe but Greeks against Greeks. With his swift tracing of Athens’s rise from a backwater polis to burgeoning power, the historian not only underscores the near-sudden fear that overtakes Sparta but also lays bare the tragic implications of the brewing collision.

In his explanation of the work’s celebrated speeches, Thucydides tells us that when he could not say with certainty what the speakers said, he had them say what they should have said. They do so not as stock figures offering insights into game theory but as flesh-and-blood individuals mostly blind to the consequences of their actions. Behind the intense debates and decisions, we hear not the muffled moves of a chess game but the grinding wheels of necessity and nemesis. The former, as the hero of Aeschylus’ “Prometheus Bound” declares, is unconquerable. The latter, as was understood by any Greek tragedian or historian worth his salt, was ineluctable.

Time and again, rational calculations prove as faulty as irrational forces prove overwhelming. Pericles, the Athenian leader praised for his ability to plan for all eventualities, dies in the unanticipated plague that strikes the city. The Athenian leader of the Melian expedition, who justifies the destruction of Melos by claiming that might makes right, portends the destruction of the Athenian expedition to Sicily.

Similarly, Alcibiades, the privileged and proud politician who promoted the Sicilian adventure, did so by appealing not to the reason of his working-class base but to its discontent and desires. Likewise, the businessman turned demagogue Cleon, blasted by Thucydides as the “most violent man in Athens,” repeatedly debases language in his quest for power. As for the reasonable and moderate Nicias, the general who failed to dissuade his fellow Athenians from invading Sicily, he dies there while commanding his doomed forces. While Alcibiades eventually goes over to the Spartans, revealing that self-interest comes before national interest, Nicias suffers what Thucydides describes as an “undeserved” death.