The Giver asked Jonas to take the pain of war from him. When Jonas comes to see The Giver in the beginning of chapter 15, he is writing in pain. He pleads for Jonas to take some pain from him. He then transmits the pain and confusion of dying on a battlefield to Jonas. He sees a boy described this way.
Dirt streaked the boy's face and his matted blond hair. He lay sprawled, his gray uniform glistening with wet, fresh blood.
Jonas also discovers that he is injured as well. He has a broken arm and is bleeding. After this experience, he thinks of war very differently and challenges Asher’s playing of war games. It is the beginning of the rift between Jonas and the others. He starts to realize he is different.