Because everyone (the people of the world) was happy in all respects, there was no resentment, although there were sometimes battles between the state kings for political reasons and supremacy
SB Canto 1
Thereafter, in the capital of Hastināpura, he enthroned his grandson, who was trained and equally qualified, as the emperor and master of all land bordered by the seas.
The total land on the earth bordered by the seas was under the subjugation of the King of Hastināpura. Mahārāja Yudhiṣṭhira trained his grandson, Mahārāja Parīkṣit, who was equally qualified, in state administration in terms of the king's obligation to the citizens. Thus Parīkṣit was enthroned on the seat of Mahārāja Yudhiṣṭhira prior to his departure back to Godhead. Concerning Mahārāja Parīkṣit, the specific word used, vinayinam, is significant. Why was the King of Hastināpura, at least till the time of Mahārāja Parīkṣit, accepted as the Emperor of the world? The only reason is that the people of the world were happy because of the good administration of the emperor. The happiness of the citizens was due to the ample production of natural produce such as grains, fruits, milk, herbs, valuable stones, minerals and everything that the people needed. They were even free from all bodily miseries, anxieties of mind, and disturbances caused by natural phenomena and other living beings. Because everyone was happy in all respects, there was no resentment, although there were sometimes battles between the state kings for political reasons and supremacy. Everyone was trained to attain the highest goal of life, and therefore the people were also enlightened enough not to quarrel over trivialities. The influence of the age of Kali gradually infiltrated the good qualities of both the kings and the citizens, and therefore a tense situation developed between the ruler and the ruled, but still even in this age of disparity between the ruler and the ruled, there can be spiritual emolument and God consciousness. That is a special prerogative.