Why did Polybius support open cooperation between Achaea and Rome?

Polybius supported open cooperation between Achaea and Rome primarily as a pragmatic political strategy during a period of shifting power dynamics. As a statesman, he recognized that Rome had become the dominant world power, having established its supremacy through military success, such as the victory over Perseus of Macedonia at the Battle of Pydna.12

By advocating for alignment with Rome, Polybius sought to protect Achaean interests and maintain stability for his countrymen. His commitment to this path was evident when he served as an envoy to the Roman consul Quintus Marcius Philippus to offer Achaean support. Even after being deported to Rome as a political detainee, he maintained his influence, eventually leveraging his close relationship with the Roman general Scipio Aemilianus to act as a mediator. Following the destruction of Corinth in 146 BCE, he successfully worked to secure favorable settlements for Greece, effectively acting as an ally to the Romans to "quench their wrath" and mitigate the consequences of the conflict for his people.23