Sledge’s drill officer (DI) in boot camp is a cold, mean man whom Sledge initially hates. He behaves condescendingly toward the recruits in his platoon, humiliating them publicly when they make a mistake and forcing them to take part in exhausting drills. However, Sledge later understands that Doherty’s unforgiving discipline and harsh attitude played a crucial role in preparing him for battle, as he insisted on the importance of following safety rules and respecting military discipline. Sledge later respects Doherty for this, understanding that discipline can make the difference between life and death in combat.