Just before the start of war, Arjun gets the feeling that war would kill many of his friends and relatives and argues that this is bad from many points of view.
Arjun’s dilemma eminates from his presumption that “I am doer” -- Aham karta and is also known as Ahankaar. This Ahankaar keeps us telling that we are distinct, but reality is different. Though ego is usually given as meaning to Ahankaar, but ego can be taken as one of many manifestations of Ahankaar.
The entire conversation is about this Ahankaar, be it directly or indirectly and Krishna gives various paths and milestones (yardsticks) to get rid of it.
If we take Kurukshetra war as a metaphor, all of us enter into a situations, like Arjun did, in our daily lives be it in family, work place and interms of health, wealth, relationships etc. As long as one lives, these dilemmas are natural till Ahankaar is understood.
Gita is about what we are and certainly not about what we know nor what we do. Like no amount of theory can let us ride a bycle nor swim, no amount of philosophy can help us unless we see life eye to eye and guiding principles of Gita would help us to to reach the final destination -the inner self which is free of Ahankaar.
From surface it appears that times have changed since Gita gyan was given to Arjun by Lord Krishna. Certainly, there is lot of change brought about by developments in science in the past couple of centuries, but in reality, from an evolution stand point of view, humans didn’t evolve any further. The internal side of dilemma remains the same. While outer manifestations (trees) might look different, inner part (roots) remain same.