The great irony of the war was that the very requisites for victory—an enormous fleet, money for rowers’ pay, and officers deployed overseas for long periods of imperial service—were inimical to the historic assumptions of rural and isolated Sparta, which heretofore had had no monetary economy. Persia finally filled the void, gave Spartan generals untold amounts of gold, and made up losses in men and matériel almost immediately. As long as Greeks were killing Greeks, the satraps of the Persian Empire were happy to subsidize the carnage.
