Being charged from a direction you cannot see and thought was safe is a frightening thing for even the bravest of troops. With his field of vision narrowed by his position in the ranks, the average soldier has only a limited knowledge of what is happening on the battlefield. If the enemy has somehow got round behind him he might reasonably assume the battle is lost. Doubt will be sown in his mind and he may become disoriented and confused. His fighting efficiency may be impaired. If he is fighting hand-to-hand combat he might even panic and flee, thinking the enemy is upon his unguarded back.