It appears from many Vedic literatures, especially histories like Srimad-Bhagavatam and the puranas, that the pious kings of old used to tour their kingdoms in order to give protection to the pious citizens and to chastise or kill the impious. Sometimes they used to kill animals in the forests to practice the killing art because without such practice they would not be able to kill the undesirable elements. Ksatriyas are allowed to commit violence in that way because violence for a good purpose is a part of their duty. Here two terms are clearly mentioned: vadhaya, for the purpose of killing, and asatam, those who are undesirable. The protecting energy of the king is supposed to be the energy of the Supreme Lord. In Bhagavad-gita (4.8) the Lord says, paritranaya sadhunam vinasaya ca duskrtam. The Lord descends to give protection to the pious and to kill the demons. The potency, therefore, to give protection to the pious and kill the demons or undesirables is directly an energy from the Supreme Lord, and the king or the chief executive of the state is supposed to possess such energy. In this age it is very difficult to find such a head of state who is expert in killing the undesirables. Modern heads of state sit very nicely in their palaces and try without reason to kill innocent persons.