In a long essay in Foreign Policy magazine, Daniel Drezner explores why zombies have become "one of the fastest-growing concerns in international relations." Zombie theory sounds silly, but there's a serious argument underneath it all. Drezner writes, "Because they can spread across borders and threaten states and civilizations, these zombies should command the attention of scholars and policymakers."

Zombie theory sounds an awful lot like counterterrorism or cybsersecurity theory, to give just two example. But the beauty of zombie theory is that it applies too all sorts of emerging trans-national security threats, including those we have yet to anticipate or imagine. "This zombie boom is -- and should be -- taken seriously. For some international relations thinkers, the interest in all things ghoulish might represent an indirect attempt to get a cognitive grip on what former U.S. Defense Secretary Donald Rumsfeld once referred to as the 'unknown unknowns' in international security," Drezner writes.

He goes on to survey three schools of foreign policy thought and how they deal with zombie theory. "The No-Drama School of Zombie Realpolitik" would apply realism to defending against zombies, which Drezner says is not so different from how realists see all threats. The "Unite-to-Fight-Zombie Liberals" would risk "accelerating" the zombie expansion but would be more likely to survive through collectivism. As for, "Neoconservatism and the Axis of Evil Dead," Drezner says the neocons are by far the best suited to fight zombies, but not quite as skilled with non-zombie threats. Drezner concludes:

In the end, what I am suggesting is that with careful planning and a consistent approach, the zombie threat can be managed. The purpose of this essay is not to make a policy recommendation or suggest that one approach is superior to another. It is up to the reader to exercise his or her own judgment in determining what to do with this information. Indeed, interested and intelligent students of world politics should use their own brains -- before the zombies do.