Every soldier must know, before he goes into battle, how the little battle he is to fight fits into the larger picture, and how the success of his fighting will influence the battle as a whole.

Meaning of the quote

Every soldier needs to understand how their small part in a battle fits into the bigger picture. They should know how their success or failure will affect the entire battle. This way, they can see how their actions contribute to the overall success or failure of the fight.