This passage points to the racist and unjust structures of power that define the country at the time. At this point, though slavery has ostensibly been abolished, Black and Native people are forced to attend combat schools to fight the shamblers while White people remain at home in relative peace and security. Considering that the novel takes place in the years immediately following the Civil War, the book then uses the unjust and racist power structures related to the shamblers as a metaphor for the way that structural racism continued to shape political policies during the Reconstruction era in the U.S.