The Black Echo is interested in how soldiers’ experiences during the Vietnam War bleed into postwar life in Southern California. Connelly addresses the topic on a psychological level through Bosch and a societal level when discussing the other veterans that Bosch meets in the novel.

Though the novel is set 20 years after the war, Bosch continues to suffer from symptoms of PTSD—nightmares, insomnia, and claustrophobia—as a result of his experience as a tunnel rat. He has clearly not processed the “rage” and “helplessness” that, according to him, everyone “touched by the war” knows (320). The psychological ramifications affect even the most unlikely aspects of his life; for example, he listens to jazz because rock and roll reminds him too much of the war, and he won’t eat Vietnamese food. At the same time, Bosch rejects psychological help; he embraces the anger and sadness because, for him, it “[is] better than complete emptiness” (320). The novel treats his decision to ignore the lasting effects of PTSD as the result of a culture of machismo: Bosch masters his terror of the tunnels in the end of the novel, jumping in to be a hero. At the same time, his refusal to get help is unfortunate because his life is dysfunctional outside of his detective work.