Who was the character foil of sunrise over fallujah?

In "Sunrise Over Fallujah" by Walter Dean Myers, the character foil to Robin "Birdy" Perry is his friend and fellow soldier, Corporal Jerry "Jonesy" Jones. While Birdy is introspective and grApples with the moral complexities of war, Jonesy embodies a more carefree and humorous attitude, often using humor as a coping mechanism. Their contrasting personalities highlight Birdy's internal struggles and development throughout the narrative, emphasizing the themes of friendship and the psychological impacts of combat.