Why are the living dead taking over our lives, and why have so many other domains of American culture, from architects to academics to departments of the federal government, been so eager to jump on this macabre bandwagon? Is it all just good, scary fun─or something we should worry about?

First we have to appreciate why zombies are so terrifying. The classic ghoul of George Romero films seems awfully slow and plodding. But what the living dead lack in speed, they make up for in other qualities. Zombies occupy what roboticists and animators call 'the uncanny valley' in human perception─though decidedly not human, they are so close to being human that they prompt instant revulsion. Another common feature of zombie narratives is that 100% of the people bitten by zombies eventually turn into zombies. Even the most virulent pathogens encountered in the real world (say, Ebola or HIV) have infection rates below 50%.

These qualities matter because they map so neatly onto the genuine threats of our day. Zombies thrive in popular culture during times of recession, epidemic and general unhappiness. Traditional threats to U.S. security may have waned, but nontraditional threats assault us constantly. Concerns about terrorism have not abated since 9/11, and cyberattacks have now emerged as a new anxiety. Drug-resistant pandemics have been a staple of local news hysteria since the H1N1 virus swept the globe in 2009. Scientists continue to warn about the dangers that climate change poses to our planet. And if the financial crisis taught us anything, it is that contagion is endemic to the global market system.

Zombies are the perfect metaphor for these threats. As with pandemics and financial crises, they are not open to negotiation. As with terrorism in all its forms, even a small outbreak has the potential to wreak massive carnage.

Because the living dead resonate so strongly with the present cultural moment, it is no surprise that various promoters and policy entrepreneurs have used them as a 'hook' for their own causes. The scholar John Quiggin published 'Zombie Economics' as a way to grab reader attention about the ill state of current economic theory. Outdoor retailer REI marketed '13 Essential Tools for Surviving a Zombie Outbreak'─each available for purchase at REI stores. The annual Zombie Safe House competition challenges architects to design the best ghoul-proof home, and zombie 'fun runs' are now regular events across North America.

Even the U.S. Centers for Disease Control and Prevention have gotten into the act. In May 2011, the CDC posted a small item on its blog about what to do if the dead should rise from the grave to feast upon the entrails of the living. Within two hours, it had gone viral; the CDC's Web server crashed from the surge in traffic.

Recognizing a good thing, the CDC soon released Zombie Preparedness 101, a comic book designed to educate readers about how to prepare against a zombie attack─which, not coincidentally, requires the same steps as preparing for natural disasters. The Department of Homeland Security soon picked up on the CDC's success and incorporated zombies into its own planning and publicity operations.

These examples highlight the positive ways that the living dead can be used to spark interest in other ideas. One of the strengths of the horror genre is that it allows people to talk about present-day problems without addressing them straight-on. The moment zombies are added to the mix, a dry public policy problem suddenly becomes a game of sorts, accessible to ordinary citizens.

Still, there's a real downside to these constant references to the living dead. The most serious problem lies in the suggested analogy. Policy entrepreneurs piggyback on zombies to capture attention, but they too often overlook a key element of zombie stories: They are relentlessly, depressingly apocalyptic. In almost all of them, the living dead are introduced in minute one, and by minute 10, the world is a wasteland. The implication is that if zombielike threats emerge, the state and civil society will quickly break down.

The apocalypse narrative matters if people implicitly accept the notion that some real-world threats will actually trigger this sort of collapse. Perception plays an important role in maintaining national resilience and public order. If Americans think that we are teetering on the brink of chaos, the apocalyptic mind-set can, in itself, help bring about that state of affairs.

Preparations for doomsday already influence policy debates. For National Rifle Association Executive Vice President Wayne LaPierre, part of the logic for opposing gun regulation is that he anticipates 'confrontations where the government isn't there─or simply doesn't show up in time.' Sen. Lindsey Graham has worried aloud about inadequate firepower if, say, 'chemicals have been released into the air and law enforcement is really not able to respond and people take advantage of that lawless environment.' When lobbyists and senators muse aloud about such scenarios, there is a problem with our political discourse.

The solution to this millenarian cul-de-sac is to create more creative zombie narratives. There will always be a place in zombie lore for the postapocalyptic visions of 'The Walking Dead, ' but we also need stories like Max Brooks's novel 'World War Z' (the source for this summer's movie), in which the adaptability, ingenuity and creativity of human beings are put on full display.

Any species that has managed to invent duct tape, Twinkies and smartphones stands a fighting chance against the living dead. Narratives about flesh-eating ghouls should remain scary─but they can also remind audiences that we have an enormous capacity to adapt to new threats and overcome them.