It’s unclear how the narrator is trying to help Sonny. He has come to kill Sonny so that he can prove himself worthy of fighting in Vietnam alongside Bon. Perhaps if Sonny were to expose himself as a Communist, too, the narrator could have arranged with Man for his protection. When Sonny fails to pick up on the narrator’s cue, it seems that the narrator has no choice but to kill him, due to having already exposed himself as a double-agent and needing to carry out the General’s order. His clumsiness in shooting Sonny is another indication of his ineptitude at performing such violent tasks.