Thucydides believed that the Peloponnesian War (431 - 404bce) was inevitable. The closing of the Greco-Persian War left the Hellenic world riven between a polarity of attractors: Sparta and Athens. For forty years the Athenians would pugnaciously push their advantage in the Mediterranean; Sparta waited, knowing from hard-fought experience that rivals come and rivals go. But the growth of Athens remained unchecked, and, despite light skirmishes, Sparta proudly maintained her supposed hegemony. But the Lacedaemonians could remain aloof for only so long. It was fated in the stars, as Athens goaded Sparta's allies, that the rival powers must clash; bringing a new order to the Hellenes.
Donald Kagan fiercely contests Thucydides inevitability thesis. To the contrary, Kagan writes, the Peloponnesian War resulted from a confluence of emergent circumstance which transcended the control and intention of those involved. Kagan emphasizes that, to speak of Sparta, Athens, or any other Greek polis, one must negotiate the passage between the internal and the external, the domestic and the foreign; the multiple and the singular. Clashes were often less between city-states and more between specific factions within each city-state; such factions would periodically wax and wane in power. It is only when such factions exercised power, thereby responding to and subsequently altering regional events, that a small undercurrent leading towards conflict swept the Greeks along towards war.
In answering Thucydides claim of inevitability, Kagan's approach reveals a different history. Inevitability as such suggests a causality in which outcomes are equal to the sum of their inputs. A certain reorganization of powers, wealth and influence. Such a history must be linear; it leaves no room for creative novelty; emergence is absent. Kagan's history is one of percolations; of folded times. Technologies are employed and actions are put-forth into a world of tentative uncertainty. When actors are co-defined, when relations create spaces of arrival which earn the name of a discrete entity, then outcomes are never fore-ordained. Kagan speaks of a different relationship with time. Rather than a linear progression of inputs and outcomes, Kagan's folded and percolated times move with fits and bursts. Events and objects replay their importance. Did they ever depart in the first place? Creative novelty emerges from the knife-edge of uncertainty. As actors wobble between co-created identities, as they become in relation to evolving circumstance, time is the result.
Change and asymmetries of outcomes demand response and re-definition, thus, the world moves forward. The Peloponnesian War far surpassed anyone's expectations; it was a war that no one wanted. Yet, the fault was not in the stars. Politicians and citizens made choices in-light of changing circumstances. Sometimes they chose well, sometimes ill. But in a co-created world there is often chance to retreat from the precipice. Rhetoric of the time suggested that each had no other alternative but conflict - at a certain point this was surely true. But all circumstance is itself a synthetic place of arrival. And each action ought to bespeak an uncertainty by the actor.