What were the weaknesses of Ancient Athens?

Athens is often praised because it operated the world's first democracy.  Within this democracy, however, were some weaknesses.  For one, citizenship and the right to vote was very limited.  Only males that owned land were considered citizens.  Also, you had to be born in Athens to become a citizen.  These restrictions excluded women, middle class, and potentially talented individuals from other city-states.  Athenian democracy also was cumbersome and operated slowly.  It took longer to make political decisions than some of the city-states that operated oligarchies did.  The government was also corrupted and dominated by the elite of the city-state.  That greed would cause Athens to seek an empire through the Delian League which alienated its neighbors.  Another weakness of Athens was that it relied heavily on its navy and did not have a strong army. These last two points would become issues in the Peloponnesian War with Sparta.