How does Levy challenge and redefine the idea of war in her novel Small Island?

Small Island emphasizes the "war at home" rather than on the battlefield. The characters' experiences of World War II are not limited to military service; they leave home and/or cope with challenges on the home front. Andrea Levy especially considers the perspective of people of African heritage, British colonial subjects, and women.
The novel's events occur before, after, as well as during the war. Gilbert is a black Jamaican man who wants to serve the British cause but, more than that, also wants to fly; he therefore joins the Royal Air Force. While he is accepted as a fellow flier, he faces discrimination off the base in everyday occurrences. One such incident leads to a fight and results in the military policeman accidentally killing another man.
Hortense, also a black Jamaican, goes to England to join her husband and to search for her cousin Michael, who has gone missing in action. Queenie, a white English woman, must cope on her own after her husband, Bernard, leaves for military service and then does not return as scheduled. This influences her decision to turn her home into a boarding house that accepts black boarders, which opens her eyes to the racism around her.
When Bernard returns, he is physically and mentally afflicted by syphilis and the trauma of having been falsely accused and imprisoned for treason. This eventually results in the dissolution of their marriage.