Do you believe athenian imperialism policies weakened or strengthened the city state and why?

Athenian imperialism only weakened the city
when Athens had forged a strong confederation with other Greek cities it was able to repel the Persians, but when they decided to turn into an empire, they lost the trust of several powerful states such as Sparta who even conspired with Persia to destroy Athens. Athens should have remained a worthy contributor in the confederation.

C:rigid class structure