How could democracy helped lead Athens to war with Sparta

Athens was a direct democracy where the male citizens controlled the activites of the cty-state, meeting every couple of weeks to make decisions. They were fairly easily led by demagogues (= leaders of the people) who brought forward plausible propositions which looked good to the people (until they learned better by later bitter experience, when they instituted a crime of ‘Misleading the People with the death penalty attached).

A chief demagogue was Pericles who was overconfident of Athens’ ability to use its walls to protect the city and port, and the navy to inflict damage on any attacking city and as well protect the import of food during a prolongued seige, and comtinue to collect the taxes it imposed on its empire to pay for all this.

The moderating conservative force of Thucydides son of Melesias and his party was lost when Pericles had him ostracised (banished from the city), so there was no coherent opposition to the opportunists bent on pushing too far the Peloponnesian League cities led by Sparta. The Assembly accepoted the urgings of Pericles and the ancompromising activists to vote f0r war, rather than the compromise for peace proposed by Sparta.