Since Arjuna was a warrior, Krishna advised him to perform his duty without self-interest. If a soldier does not want to engage in war but wants to be a mendicant instead, as proposed by Arjuna, then he should not join the army. It is paradoxical to join the army and then refuse to fight when the need arises. The army has the responsibility to protect a nation from its enemies. By engaging in warfare when necessary, the army grants a peaceful life to the civilians. The duty of a policeman, a soldier or a king, is to be impartial for the sake of the nation, even if they have to stand up against their own teachers or relatives.
Krishna is not propagating violence. Rather, he is imploring Arjuna to vanquish the enemies, i.e. his cousins, who plotted to kill him and his brother surreptitiously by poisoning their food, setting fire to their residence and other such hideous means. A soldier protects citizens and prevents violence.
You have to have a clear definition of your goal – what do I want? What am I heading for? You have to have a very clear definition of what is Bhakti. If you are not clear, then you can remain in a hazy field for a long time. That is the significance of Nyaya. It gives clear definitions, which is very important. Otherwise you may think that this is the definition of Bhakti and I am doing Bhakti, but what you may be doing may not fit the definition.
