The novel was published amid a background of ongoing wars—Afghanistan and Iraq—wherein the memories of the 9/11 terrorist attacks and the establishment of Homeland Security was still fresh. America had elected its first Black president, and the nation had been plunged into the Great Recession, a time of deep economic insecurity. Under the Dome traces the fault lines among a populace who are divided politically, economically, and culturally. Setting the novel in the very near future—it was published in 2009, though the action appears to take place in 2012—allows the author to explore how far and how deep those fault lines might go and how long they may take to rupture in a crisis. The Dome, with its extraterrestrial origins and claustrophobic environment, allows the author to exaggerate the effect of those divisions.

The novel’s protagonist, Dale Barbara, is a decorated Iraq War veteran, a status that he would rather ignore. His attitude toward his service is ambivalent at best—he threw his medals into the Gulf of Mexico more than a year before—and he remembers the enhanced interrogations of Iraqi prisoners with remorse. He is deeply mistrustful of the military and its motives.