The unnamed spy
This is our hero and protagonist, an admittedly violent military person who ends up living in America as a spy for the Communists (or else he is crazy from PTSD; later events in the book suggest this might be the case). He often ends up in skirmishes that exploit the different points of view about the Vietnam war. He tells us this story from jail, it seems, but many aspects of his point of view are confusing and occasionally, they are completely inconsistent.
General Bon
This Vietnam officer knows the truth about America's involvement in Vietnam, and he also understands how humiliating it is to live in America as a foreigner, because racism and disenfranchisement of minorities make life grueling and emotionally challenging, because in Vietnam, he was used to a kind of general honor and respect among the community. Is this a real character or a figment of the spy's imagining? That is for the reader to decide.
Sonny
Sonny makes a serious mistake when the spy leaves to the Philippines to be in a film about the Vietnam war. He sleeps with the spy's girlfriend, and when the spy returns to Los Angeles, he learns about it and decides to leave America for good, because they are mischaracterizing the war in Vietnam for propagandist reasons, but first, he executes Sonny in cold blood.