The Politics of the Ethics of War

From what I read on the Fog of War website, I feel I will gain a far better insight and perspective on what people in positions of power must go through to make wartime decisions. Understanding what leaders must experience (ie public perception, pressure from colleagues, changing principles) must be addressed to fully grasp how war conduct is played out. It is easy to disregard the factors that leaders are subject to while in office. However, this can lead to incomplete conclusions.
What compels me the most about viewing this film is that this is the first study on actual events. Instead of engaging in hypothetical theories, we can undertake ideas that have a true nature and existence. I believe this is equally as important as studying theories.
In regards to the substance of the film, one thing that got my attention was McNamara's life and how he lived through many changes and developments in warfare. Questions that immediately arise: Did McNamara's ethics of war change with the advancement of weaponry and warfare? Can the ethics of war be fickle or are they set of principles that do no change?
I also am looking forward to viewing a leader who must make decisions on warfare from a subjective point of view. What can we understand about the ethics of war by seeing it through the leaders eyes? Once you throw yourself into the position of making difficult wartime decisions, I believe many peoples perceptions of the ethics of war can easily be amended.
The last dynamic that I want to address is the relations between McNamara and JFK and LBJ. The website explains that studying the tape recordings between McNamara and others can lead to a completely different conclusion about who was truly dictating the war agenda. Is focusing on the relations between people in power an important lens we must look through to better understand how our leaders conduct war?
I recognize most of what I have taken on here does not address the actual theories of war ethics. On the other hand, comprehending war ethics through more pragmatic and face value terms may lead to practical results.