The main conflict between the Athenians and Spartans during the Peloponnesian War revolved around power, influence, and differing political systems. Athens represented a democracy and a naval empire, seeking to expand its influence over the Greek world. Conversely, Sparta embodied a militaristic oligarchy focused on land-based dominance. Tensions escalated as Athens' Delian League threatened Spartan interests, leading to a brutal conflict from 431 to 404 BCE. The war represented not just a struggle for supremacy between these city-states but also reflected broader ideological divisions in ancient Greece, ultimately resulting in the decline of Athenian power and the temporary dominance of Sparta.