Śrīmad-Bhāgavatam 1.10.6

To be nonviolent to human beings and to be a killer or enemy of the poor animals is Satan's philosophy. In this age there is enmity toward poor animals, and therefore the poor creatures are always anxious. The reaction of the poor animals is being forced on human society, and therefore there is always the strain of cold or hot war between men, individually, collectively or nationally. At the time of Mahārāja Yudhiṣṭhira, there were no different nations, although there were different subordinate states. The whole world was united, and the supreme head, being a trained king like Yudhiṣṭhira, kept all the inhabitants free from anxiety, diseases and excessive heat and cold. They were not only economically well-to-do, but also physically fit and undisturbed by supernatural power, by enmity from other living beings and by disturbance of bodily and mental agonies. There is a proverb in Bengali that a bad king spoils the kingdom and a bad housewife spoils the family. This truth is applicable here also. Because the King was pious and obedient to the Lord and sages, because he was no one's enemy and because he was a recognized agent of the Lord and therefore protected by Him, all the citizens under the King's protection were, so to speak, directly protected by the Lord and His authorized agents. Unless one is pious and recognized by the Lord, he cannot make others happy who are under his care. There is full cooperation between man and God and man and nature, and this conscious cooperation between man and God and man and nature, as exemplified by King Yudhiṣṭhira, can bring about happiness, peace and prosperity in the world. The attitude of exploiting one another, the custom of the day, will only bring misery.