Reviewers have noted that Brooks uses World War Z as a platform to criticize government ineptitude, corporate corruption, and human short-sightedness. At one point in the book, a Palestinian refugee living in Kuwait refuses to believe the dead are rising, fearing it is a trick by Israel. Many American characters blame the United States' inability to counter the zombie threat on low confidence in their government due to conflicts in the Middle East.
Brooks shows his particular dislike of government bureaucracy. For example, one character in the novel tries to justify lying about the zombie outbreak to avoid widespread panic, while at the same time failing to develop a solution for fear of arousing public ire. He has also criticized American isolationism:
I love my country enough to admit that one of our national flaws is isolationism. I wanted to combat that in World War Z and maybe give my fellow Americans a window into the political and cultural workings of other nations. Yes, in World War Z some nations come out as winners and some as losers, but isn't that the case in real life as well? I wanted to base my stories on the historical actions of the countries in question, and if it offends some individuals, then maybe they should reexamine their own nation's history.
Survivalism and disaster preparation are other 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 plumber could hold a higher status than the former C.E.O.; 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.
Fear and uncertainty
Brooks considers the theme of uncertainty central to the zombie genre. He believes that zombies allow people to deal with their own anxiety about the end of the world. Brooks has expressed a deep fear of zombies:
They scare me more than any other fictional creature out there because they break all the rules. Werewolves and vampires and mummies and giant sharks, you have to go look for them. My attitude is if you go looking for them, no sympathy. But zombies come to you. Zombies don't act like a predator; they act like a virus, and that is the core of my terror. A predator is intelligent by nature, and knows not to overhunt its feeding ground. A virus will just continue to spread, infect and consume, no matter what happens. It's the mindlessness behind it.
This mindlessness is connected to the context in which Brooks was writing. He declared: "at this point we're pretty much living in an irrational time", full of human suffering and lacking reason or logic. When asked in a subsequent interview about how he would compare terrorists with zombies, Brooks said:
The lack of rational thought has always scared me when it came to zombies, the idea that there is no middle ground, no room for negotiation. That has always terrified me. Of course that applies to terrorists, but it can also apply to a hurricane, or flu pandemic, or the potential earthquake that I grew up with living in L.A. Any kind of mindless extremism scares me, and we're living in some pretty extreme times.