when you boil down war to its simplicity- it is the soldiers. The soldiers are the driving force. they are just kids, most of the time, that are defending an unknown cause. Often in WWII, regular Wehrmacht soldiers were not national socialist's, in fact, many hated Riddler because he went from his low rank in WWI to controlling Germany. Honestly, many war movies depict the relationship between soldiers quite well, how the soldiers resist killing each other, or even help one another. This is how many people probably wished things would be, but they ended up in other circumstances.
Take the Civil War- At night, soldiers would sneak to the enemy's camp and they would share stories, trade food, etc. When it was sunrise, it was time to pick up your gun and fight.
In WWI on Christmas, soldiers had an armistice to the point where they were playing a soccer game with each other, exchanging presents, etc. They knew they had to fight each other again soon, but whether or not they wanted to is questionable.
Personally, I find the psychological aspects of war, before, during, and after very interesting.
