In the Bhagavad Gita, there is no long discussion, nothing elaborate. The main reason for this is that everything stated in the Gita is meant to be tested in the life of every man; it is intended to be verified in practice.
There never has been a war yet which, if the facts had been put calmly before the ordinary folk, could not have been prevented. The common man, I think, is the great protection against war.