Why War?

Tim O'Brien, through short disconnected stories, shows the many sides of war. His stories are from the Vietnam war and describe the different experiences of soldiers in Vietnam. Some stories are lighthearted and show the growth that soldiers experience when they go to war. They learn valuable lessons and make friends with other soldiers. They have fun with each other.
The majority of the stories, though, show the darker side of war. O'Brien, sparing the reader no gory details or raw emotions, writes of soldiers watching fellow soldiers explode before their eyes. Young men, teenagers, must go to war with their friends and come home without them. They must destroy the lives of other human beings. They must be men and hide all of their emotions. They must follow orders and be proper soldiers.
And for what are they doing all of these things? Reading these stories makes me think that the soldiers themselves, the ones in the war, are in fact the ones most disconnected from the war. The soldiers stories are personal stories. They are stories about growing up and learning about love and loss and pain. But they are not really about the Vietnam War. The reader does not finish The Things They Carried with a more expansive knowledge of the causes, outcomes, or politics of the Vietnam War- because soldiers fighting in Nam are different than the opposing political leaders and groups who began the war. The war is not between the individual soldiers; it is between the groups that the soldiers represent.
So it begs the question, why do we fight wars? Is it possible for opposing nations and opposing groups to solve problems without losing the lives of countless soldiers along the way? Is it possible to resolve disputes without bloodshed? Maybe not, maybe war is inevitable. Changes in history are marked by wars. But I'd like to think that someone, someday, will find a way that works for us to solve issues without losing any lives.