Hare Krishna!
The Mahabharata mentions that at the end of Kurukshetra, there was only one person who went back to Godhead. That person was Bhishma Pitama.
Bhishma knew he was fighting on the wrong side, he knew Krishna was the Supreme Personality of Godhead.
On the battlefield of Kurukshetra he lifts his sword to fight Krishna in a Virya Rasa, when Krishna, who had vowed not to fight in the war but to save His friend and devotee Arjuna from Bhishma, picks up the chariot wheel to fight Bhishma. Still, Bhishma left his body and went back to Godhead. Because his mind was always absorbed in Krishna while performing his duties.
Bhishma was bound by his promise to fight along with the Kauravas though he knew they were wrong. Since he fought as a matter of duty, with his mind and intelligence surrendered at the feet of the Supreme Lord, without any ill-will to the Pandavas, his actions were 'akarmic', incurring no sin.
Man sees the face, but God sees the heart. A policeman kills a criminal in his line of duty without any hatred for that person, a soldier fighting a war kills the another soldier in the line of duty without any ill-will or ill feelings, with his mind totally surrendered to the Supreme, does not attract any bad karma. God sees the intent, not your action. You may not lift a finger against another, but you have hatred in your heart for that person, you incur the reaction of Karma.
In the same war Bheema kills Duhasana and rips his heart out and drinks his blood in rage and hatred (because Duhasana had gestured his Draupadi to sit on his lap after the Pandavas lost in the game of dice), he had to go to hell for his action, because his act was born of hatred and revenge.
So violence as a matter of duty or self-defense without any ill feelings does not attract sin and is given divine sanction in the scriptures.
There are 4 kinds of violence
1. Physical violence should never be tolerated. The method of fight or flight should be adopted if one is being physically violated or abused.
2. Emotional violence is the only violence that should be tolerated and welcomed, because that is an ego leveler. It makes one humble. It brings humility to a person who is full of arrogance or pride when he/she is emotionally abused.
3. Intellectual violence should also be not tolerated when one is not allowed to study or pursue his studies and career.
4. Spiritual violence is the the worst. This is what the Pandavas were fighting the war at Kurukshetra for. They were not allowed to carry out their 'Svadharma', the purpose they were born for as Kshatriyas. The Svadharma of a Brahmana is to educate and bring harmony among all. The Svadharma of the Vaisya is to create wealth through business and the Svadharma of a Sudra is to work diligently under a master. When any of these are not allowed to perform their God given duties (Svadharma), that amounts to Spiritual violence which is the worst form of violence and should be strongly opposed.
In all circumstances, we have to perform every action selflessly with our mind surrendered at the feet of the Lord, so that at the time of leaving this body we go back to Him with no worldly attachment or desire to come back in another body to fulfill those desires, except the soul's desire to please Krishna.
Krishna clearly states that we, the souls, are eternal. But we change form as per the mind we have shaped during this life. The mind is the tool which, if used properly, in service of Krishna by remembering Him in all our thoughts, words and deeds, then we become Jeevan Mukta (Liberated while in this body). Then it does not matter whether we are in the body of Brahmana, Kshatriya, Vaisya or Sudra, because the suffering of this world will be like pin-pricks.
So it is the mind and mind alone which is the cause of bondage within this world. It keeps bringing us back to this endless cycle of birth, death, old age, disease, fault, misfortune and unhappiness when one's endless worldly desires remain unfulfilled.
Hare Krishna!
Comments