 <unk> and disaster preparation are prevalent themes in the novel . Several interviews , especially those from the United States , focus on policy changes designed to train the surviving Americans to fight the zombies and rebuild the country . For example , when cities were made to be as efficient as possible in order to fight the zombies , the <unk> could hold a higher status than the former <unk> ; when the ultra @-@ rich hid in their homes , which had been turned into fortified compounds , they were overwhelmed by others trying to get in , leading to mass slaughter . Throughout the novel , characters demonstrate the physical and mental requirements needed to survive a disaster . Brooks described the large amount of research needed to find optimal methods for fighting a worldwide zombie outbreak . He also pointed out that Americans like the zombie genre because they believe they can survive anything with the right tools and talent . 
