Final answer:
In the aftermath of the Peloponnesian War, Greeks sought understanding through diplomacy, culture, and education to negotiate alliances and reshape their society, leading to an era of political change and eventual Macedonian conquest.
Step-by-step explanation:
After the Peloponnesian War, the Greeks turned to diplomacy, culture, and education for understanding and building alliances. The war challenged Greek views on their own cultural superiority and brought about a transition from traditional hoplite-based social structures to ones where diplomacy and cultural finesse gained prominence, with Sparta even allying with the Persians. This period also marked the beginning of the decline of the classical Greek era, as the costly conflict with Sparta ultimately checked Athens' imperial ambitions, leading to further political fragmentation and vulnerability to Macedonian conquest under Philip II and Alexander the Great.