Civil Strife Caused by Differences in Government Ideals
In his histories, Thukydides payed much attention to 2 phenomena, giving a prominent example for each; the first was the condition of demagoguery; the second was civil strife in allied poleis caused by conflict between democratic and oligarchic parties. The primary example given was the polis of Corcyra (known from the late high medieval period as Corfu), which was credited as one of the causes for the Peloponnesian Wars.
The oligarchs represent the pro-Spartan faction and the democrats represent the pro-Athenian faction. However, the clashes are almost purely for personal gain, instigated by Spartans and Athenians, and as pointed out by the Athenian General Phrynikus, who was initially opposed to Alkibiades and Pisander’s plan for Athens to become an oligarchy, saying that it will neither secure the loyalty of allied oligarchic poleis nor pacify hostile oligarchic poleis.