The Peloponnesian War (431–413 BC) was an Ancient Greek military conflict, fought by Athens and its empire against the Peloponnesian League, led by Sparta. In the first phase of the war, the Archidamian War, Sparta launched repeated invasions of Attica, while Athens took advantage of its naval supremacy to raid the coast of the Peloponnese, while attempting to suppress signs of unrest in its empire. This period of the war was concluded in 421 BC, with the signing of the Peace of Nicias. That treaty, however, was soon undermined by renewed fighting in the Peloponnese. In 415 BC, Athens dispatched a massive expeditionary force to attack Syracuse, Sicily; the attack failed disastrously, with the destruction of the entire force, in 413 BC. This ushered in the final phase of the war, wherein Sparta, now receiving support from Persia, supported rebellions in Athens' subject states in the Aegean Sea and Ionia, undermining Athens' empire, and, eventually, depriving the city of naval supremacy. The destruction of Athens' fleet at Aegospotami effectively ended the war, and Athens surrendered in the following year.
In a bid for personal glory as much as anything else, Alkibiades helped restart the Peloponnesian War. In 415 BC, Athens dispatched a massive expeditionary force to attack Syracuse in Sicily; despite the political cloud that hung over Alkibiades, the expedition was a success, and Syracuse became an Athenian puppet. Flush with victory, the Athenians attacked Sparta itself causing much death and destruction. This forced king Agis to sue for peace ending the conflict among the Greek states.
When Bryce Miller became an assistant professor at Wayne State College, he taught a class on Ancient Greece, including the Peloponnesian War. He did wonder what the kids he was teaching thought of things like the Melian Dialogue. Some seemed to get how it applied to any situation including modern politics but others didn't.