History of the Peloponnesian War

The policy of Lacedaemon was not to exact tribute from her allies, but merely to secure their subservience to her interests by establishing oligarchies among them; Athens, on the contrary, had by degrees deprived hers of their ships, and imposed instead contributions in money on all except Chios and Lesbos. Both found their resources for this war separately to exceed the sum of their strength when the alliance flourished intact.