What Is the moral of Private Peaceful?

In my opinion, Michael Morpurgo, is challenging us as readers to rethink the definition of bravery.... the morality of those who deem one level of bravery as less than another. Morpugo is exposing the infinite shame placed upon those who found themselves unable to move in the face of carnage..... young, inexperienced boys, who lost their lives and were buried as cowards, executed as traitors, remembered for what they couldn't do rather than what they did do. Illustrating the concept of the enemy beside them, as opposed to the enemy wearing another uniform just across the way.....