Zombies allow people to deal with their own anxiety about the end of the world. Night of the Living Dead and its counterparts also illustrate the fear of widespread apocalyptic destruction. It is not a coincidence that these movies appeared mostly at the height of the Cold War paranoia. Much like the atomic bomb, zombies are unleashed in a chain reaction, each devoured corpse arising and looking for more human flesh to consume.
Like any Apocalypse, mankind is striken because of its decadence. In Romero's zombie trilogy, the flesh-eating dead threaten a society already lost, whether the source of that loss be violence, hate, bureaucracy or stupidity. The media, the military, science, philosophy are all helpless to provide an answer. The violence and spiritual void of human society feeds upon itself and the result is an apocalypse of the dead. Zombies also represent widespread annihalation in the form of plague-like sickness.
The implications here are basically the same as they are with nuclear apocalypse, but on a more personal and intimate level. As the zombie count increases exponentially, they cover more and more distance until they overtake massive amounts of land area. Indeed, by the end of Romero's Day of the Dead (1985), the final installment of his trilogy, only a small band of military survivors is remaining in the United States. Consequently, they choose to relocate to an uninhabited island in the tropics as the U.S. becomes a barron wasteland, populated only by the walking dead. Will the Arch of Noha bring the renewal ?
But there are no six-head dragons and the devil to defeat. Since the seventies, the 'zombie master' has disappeared and the zombies function as an independent menace without any control. The enemy is within us and us only, not some "other" or tyrannical force from beyond or outter space. This zombie apocalypse is, unlike the alien mutant movies of the previous decade, solely rooted in mankind.
Clive Barker has commented that, since organised religion is losing its ability to popularly explain the world, Romero's living dead represent the only immortality possible. They are the tyranny of flesh, immortality without a spiritual dimension. And they are implacable. In extreme cases, nothing will stop them, certainly not our usual bulwarks of law, order, love, sex and reason. Zombies, Barker reckons, are the archetypal monster for the latter part of the twentieth century.