In a perfect human civilization there must be a class of men fully trained as perfect brahmanas. Similarly, there must be ksatriyas to rule the country very nicely according to the injunctions of the sastras, and there must be vaisyas who can protect the cows. The word gavah indicates that cows should be given protection. Because the Vedic civilization is lost, cows are not protected, but instead indiscriminately killed in slaughterhouses. Such are the acts of demons. Therefore this is a demoniac civilization. The varnasrama-dharma mentioned here is essential for human civilization. Unless there is a brahmana to guide, a ksatriya to rule perfectly, and a perfect vaisya to produce food and protect the cows, how will people live peacefully? It is impossible.

From Srila Prabhupada's purport to SB 7.2.12