The Peloponnesian War affected how mass and elite interacted at Athens and how the public sphere worked there. The Athenians themselves thought in terms of two ruptures, one at the death of Perikles, one at the end of the war. But the degree of rupture in both cases has been exaggerated, and it is better to think in terms of how power was exercised. Here we see various ways in which the people’s control of the elite was strengthened during the war, and indeed the use of exile and atimia (disenfranchisement) as penalties fatally weakened Athens by causing factional strife. The Peloponnesian War concentrated the people inside Athens and the Long Walls and increased the number of spaces in which Athenians were mixed up with metics and enslaved people, enhancing the deep politicisation of Athenian culture, which affected the wealthy as well as the poor and promoted the hetaireiai and, eventually, concentration of political factions into particular spaces. War enhanced the Athenians’ emotional investment, and this came out in particular over the Sicilian Expedition. It was because war affected the Athenians in a variety of different ways, each with their own timescale, that the traumatic effects emerged only after fifteen years.