Arjuna was a ksatriya, trained up by Dronacarya how to kill.  Nonviolence is not the business of the ksatriya. That is cowardice. They are taught how to become violent. Otherwise, they cannot rule over. Formerly the judgement was given by the king, immediately finished. Not go to the court and wait for the judgement for ten years. In the meantime everything is finished. Not like that. Regularly, the king used to sit in his assembly, and all the criminals, culprits, they were judged by the king himself. Sometimes the king had to kill personally with the sword. Even in European countries, the royal orders were trained up. Nowadays it is constitutional, democratic government. The king has no power. But this is not good for the people. The democracy is a farce.

Srila Prabhupada, lecture on BG 1.28-29 — London, July 22, 1973