Answer:
They had a Senate.
Step-by-step explanation:
The Senate consisted of representatives of every rank on the social pyramid of Athens, (except for slaves and women). Then they would make laws together and decide if go to a war or not. That's a direct democracy there is a main leader but he can be taken out and put by someone else, the Senate had much more power than the leader. That's why they succeeded on how to negotiate and act on a war.