The Chocolate War can justifiably claim to be the novel which persuaded commentators to take young adult literature seriously as a new genre. The novel caused controversy on its publication and has continued to do so since. Several attempts have been made to ban it from school and college libraries and from recommended reading lists. Objections range from a general distaste for the book's portrayal of triumphant evil to specific criticism of the language used by the boys and the depiction of sexual activity. Chapter 15 recounts how Archie discovered Emile Janza masturbating in the toilet and pretended to take a photo. "Stepping into the men's room to grab a quick smoke, Archie had pulled open the door to one of the stalls and confronted Janza sitting there, pants dropping on the floor, one hand furiously at work between his legs." It was unusual to find such frank description of adolescent sexual activity in a book published for children.
It was even more unusual, outside of fantasy literature, to encounter truly evil characters in children's books. As Nancy Veglahn commented in The Lion and the Unicorn: A Critical Journal of Children's Literature: "Robert Cormier is one of the few writers of realistic fiction for young adults who creates genuinely evil characters. Unlike fantasy and science fiction books, which abound with embodiments of cosmic malevolence, realistic novels seem to shy away from villains... [This] is not true of Robert Cormier. There is no moral blandness in his books, no picture of a world in which all will be well if everyone just tries a little harder."
It is exactly Cormier's refusal to end his books on a note of hope or uplift which his critics complain about. Six years after The Chocolate War's first publication, Norma Bagnail, writing in Top of the News, challenged the notion that Cormier was a writer of realistic fiction. Was it realistic to depict a world in which there were no decent characters capable of standing up to evil? In the case of this particular novel, she especially objected to the fact that there is no adult character in the novel ready and able to give Jerry support. "It is as inaccurate to present only the sordid and call it realistic as it has been in the past to present only the idealistic." According to the critic, the fact that the book is "brilliantly structured and skilfully written" made its distorted view of reality all the more dangerous.
This viewpoint was echoed soon afterwards by Fred Inglis, in his The Promise of Happiness: Value and Meaning in Children's Fiction. Taking Bagnail's objections one stage further, Inglis argued that there was a group of new writers for older children who were systematically destroying innocence by breeding a mood of cynicism. He chose Cormier and The Chocolate War as an exemplar of this. "What is deeply wrong with The Chocolate War ... is its grossness and indelicacy in telling its child readers that heroism is, strictly, such a dead end." He later added, "The intention of The Chocolate War seems to be to force the child directly up against the pain of pain, the facts of cruelty and oppression, by way of showing him that the adults have always told lies about the world's being a fine and benign place."
Although the book still finds its critics, it is noticeable that earlier detractors such as Bagnail and Inglis seemed to fail to grasp that the book was addressed to a new audience. It was not a book for children, but for young adults. The book's intended audience made it an immediate commercial success. It has been continually available since first publication and along with subsequent novels has helped to establish Cormier's position as America's leading young adult novelist. Sylvia Patterson Iskander, writing in the Concise Dictionary of American Literary Biography, included the following summary: "[Cormier] has brought controversy and, simultaneously, a new dimension to the field of young-adult literature. He has earned the respect of his readers, regardless of their age, because of his refusal to compromise the truth as he sees it."