War is a matter not so much of arms as of money. - Thucydides

It is a general rule of human nature that people despise those who treat them well, and look up to those who make no concessions.

When they (Lacedaemonians) had retreated, the Athenians posted guards to keep watch both by land and sea, a precaution which they maintained throughout the war. They then passed a decree reserving of the treasure in the Acropolis a thousand talents: this sum was set apart and was not to be expended unless the enemy attacked the city with a fleet and they had to defend it. In any other case, he who brought forward or put to the vote a proposal to touch the money was to be punished with death.

They also resolved to set apart yearly a hundred triremes, the finest of the year, and to appoint trierarchs for them; these they were only to use at the same time with the money, and in the same emergency.

(Book 2 Chapter 24)

Love of power, operating through greed and through personal ambition, was the cause of all these evils. To this must be added the violent fanaticism which came into play once the struggle had broken out. Leaders of parties in the cities had programmes which appeared admirable – on one side political equality for the masses, on the other the safe and sound government of the aristocracy – but in professing to serve the public interest they were seeking to win the prizes for themselves. In their struggles for ascendancy nothing was barred; terrible indeed were the actions to which they committed themselves, and in taking revenge they went farther still. Here they were deterred neither by the claims of justice nor by the interests of the state; their one standard was the pleasure of their own party at that particular moment, and so, either by means of condemning their enemies on an illegal vote or by violently usurping power over them, they were always ready to satisfy the hatreds of the hour. Thus neither side had any use for conscientious motives; more interest was shown in those who could produce attractive arguments to justify some disgraceful action. As for the citizens who held moderate views, they were destroyed by both the extreme parties, either for not taking part in the struggle or in envy at the possibility that they might survive.