Are we becoming immune to war?

At the Big Think website, John Horgan argues that war is just a cultural practice that humankind could eventually abandon, unless we keep infecting ourselves with the "war virus" (h/t Andrew Sullivan). If one state gets infected by war-proneness, so his argument runs, its neighbors may have no choice but to follow suit and adopt similar measures in order to prevent themselves from being conquered. In Horgan’s words (as reported by Mark Cheney here):

"Imagine your neighbor is a violent psychopath who is out for blood and land. You, on the other hand, are person who wants peace. You would have few options but to embrace the ways of war for defense. So essentially your neighbor has infected you with war."

It’s an arresting use of language, perhaps, but the history of social Darwinism should have taught us to be wary of bringing misplaced biological analogies into the study of world politics. Viral infections spread by very specific and well-known mechanisms — e.g., they take over the DNA of neighboring cells and replicate themselves-and that’s not remotely like the mechanism that Horgan is identifying here. Instead, he’s actually describing a situation where an external threat forces the leaders of neighboring states to rationally choose to adopt policies and strategies designed to insure their survival. That’s not how viruses spread: You don’t catch a cold because you’ve decided the only way to protect yourself against your sneezing neighbor is to start sniffling and sneezing along with them.

The actual logic that Horgan is pointing to here is the basic "security dilemma" that realists have been talking about ever since John Herz. In a world where no agency or institution exists to protect states from each other, each is responsible for its own security. Because states cannot know each other’s intentions with 100 percent certainty (either now or in the future), they have to prepare for the possibility that neighbors may do something nasty at some point. So they invest in their own armed forces or they look for powerful allies, especially if they think the possibility of trouble is fairly high. And once they do that, others have to worry about them in turn. This is the "tragedy" of great power politics identified by my colleague John Mearsheimer, and it’s a much better explanation for security competition (and war) than some analogy to microbes.

To be fair, Horgan’s larger point is simply that war is not a biological necessity; it is a specific political or cultural response to certain conditions and thus in theory could gradually be abandoned. This theme has been developed at length by John Mueller and more recently by Steven Pinker. I agree with Pinker’s claim that the overall level of human violence has declined significantly over the past several centuries (mostly due to the emergence of increasingly stable domestic political orders, i.e., states), but I remain agnostic about the larger claims for a long-term reduction in inter-state violence. That trend is driven almost entirely by the absence of great-power war since 1945, and the absence of great-power war may have multiple and overlapping causes (bipolarity, nuclear weapons, the territorial separation of the U.S. and USSR during the Cold War, the spread of democracy, etc.) whose persistence is hard to forecast.

The absence of great-power war is a good thing, because major powers have the most capability and can do the greatest harm when their destructive capacities are fully roused. What we’re seeing instead, however, is either protracted conflicts among warlords, insurgents, or relatively weak states (think the Congo, Sudan, or Colombia), and wars of choice waged by the United States and other powerful states in various strategic backwaters, mostly against adversaries that we don’t think can do much in response. At least we hope not.