Krishna looks at the teary eyed Arjuna and asks with a laugh 'What happened Arjuna? You appear to talk intelligently, but you express grief for those who do not deserve to be grieved. Those who know, will neither grieve for the dead nor those who are yet to die. You, I and all the kings were existing earlier and will continue to exist in the future. Even if the body falls the atma will continue to exist. As long as this body is alive it passes through the stages of childhood, youth and old age and it passes on ... and then again gains a new body. As we throw our old clothes and wear new ones. Similarly atma leaves old bodies and enters a new one. Which weapon can destroy the atma? In addition, those born must die. Also war is a khsatriya dharma. It is an open door to heaven for the war heroes. If you do not fight, you forsake your dharma and it is a sin. Also your enemies will speak ill of you. For an honourable man, a bad name is worse than death. So do what is required to be done, regardless of the results. One who works with committment is never unhappy, his mind is steady and he will have peace. Without peace will there be happiness?'
'Action is much superior to inaction! Do you believe that sitting quiet is inaction? No one can avoid action even for a split second. Nature ensures that there is constant action. Even the very learned are under its control. Can you stop its functioning? To think you can ,is just your ego. You are a khsatriya; rushing eagerly to fight is the true nature of your caste. If you think otherwise it is due to your ignorance. Bound by your nature and your karma, you have to do what you are required to do. It is now the time for destruction. All those here are bound to die, whether you are here or not. We can even say that they are already dead. Look at vishwaroopa, you can see it for yourself.'
'Renunciation is not just avoiding work. Doing your work devoid of expectations is sanyasa. Working without aiming at rewards is sanyasa. You should not give up work that is ordained. Ishwara sits in everyone's heart turns everything around like a machine. Have faith and leave it to him. You will have peace of mind. Anyway it is now left you. Do what you think is right!'
The terse pep talk by Krishna is closer to my understanding of what is needed to overcome the last minute nervousness of a warrior.