A week before I deployed to Afghanistan in 2010, my wife and I volunteered for a few hours at our daughter's elementary school. As we left, her teacher told the students that I was an officer in the Marine Corps about to leave on deployment. "A nation does not survive," he said, "without men like that."

It was a heartfelt statement. I thought of it often while in Afghanistan; it felt most poignant when my detachment of transport aircraft flew each one of the 119 bodies out of Helmand province between June and December 2010 to make their final trip home. Near the end of our deployment, I asked my fellow marines to always remember the fallen. I asked the living to honor the sacrifices of their dead. Not by mourning forever, nor by seeking vengeance, but by honoring their comrades' sacrifices in the choices and actions of their own lives.

I asked them, in the words of Oliver Stone's movie about another war, to find a meaning and goodness in this life.