Both Athens and Sparta wanted to be the most powerful city-state in their region.This competition led to clashes between the two city-states and their allies because there were many differences between the two city-states.
We are the better city-state!
Athens spent money from the Delian League, intended for the mutual protection of all city-states. Sparta and other city-states stood up to Athens and declared war.This was the start of the Peloponnesian War.
Sparta is finished with Athens wasting money! We declare war!
Sparta's strategy was to cut off Athens food supply by destroying their crops.
BURN ALL THE CROPS!!!
ATTACK SPARTA'S ALLIES!!!
Athens planned on winning by attacking Spartas allies and getting all their food from the ocean.
In the second year of the war Athens became over crowded because of Pericles' plan to bring all the citizens into the city walls.The plague broke out killing 1/3 of the population including Pericles.
10 years into the war Athens singed a truce to stop fighting.Eventually Athens completely surrendered to Sparta.