The civil war in Syria came back into the news the other day, when our government warned Bashar al-Assad that should he use chemical weapons against rebels and the population that surrounds them, he will have crossed a "red line." The consequences of the red-line-crossing were left unspoken. Perhaps military action on the rebels' side? An indictment in the International Criminal Court? We don't know, but it'll be bad.
Dominic Tierney beat me to it, but this news raised something I've found troubling for a long time. If you order your own civilian population to be shot, burned to death, or cut to pieces with shrapnel, the international community will be very displeased. But if you order that population to be killed by means of poison gas, then that's much, much worse. But seldom do we ask why.
So what is it that makes chemical weapons more morally abhorrent than guns or bombs? We often lump chemical weapons in with biological and nuclear weapons as "weapons of mass destruction," but the three are enormously different from one another. The problem with nuclear weapons isn't that they kill in gruesome ways, but that they kill large numbers of people all at once (not to mention those who die in the ensuing days from radiation poisoning). They're terrifying because of their awesome power to create death and destruction. As it turns out, with some creativity we've managed to create similar mass death with "conventional" weapons. For instance, the death tolls at Hiroshima and Nagasaki are estimated at around 150,000 and 75,000, respectively. In the fire-bombing of Tokyo in March 1945, a "conventional" attack, around 100,000 people, the overwhelming majority of them civilians, died in a single night. Nevertheless, we still consider nuclear weapons so awful because they can kill thousands or millions with the press of a button.
Biological weapons pose a similar danger, with the added problem that they spread exponentially and indiscriminately. We may one day be able to aim a bioweapon at an individual, but they're terrifying because once released they can't be controlled.
So what is it about chemical weapons that puts them in the same category? I've never seen anyone explain what it is. Getting killed by mustard gas is surely awful. But so is getting blown up by a bomb. Using one against your enemies gets you branded a war criminal, but using the other doesn't. The Aum Shinrikyo cult conducted a poison gas attack in the Tokyo subways in 1995, killing 13. No one could claim that because they used a chemical weapon, that attack was worse than, say, the 2005 bombings of public transport in London, in which 52 people died.
Tierney argues, "Powerful countries like the United States cultivate a taboo against using WMD partly because they have a vast advantage in conventional arms. We want to draw stark lines around acceptable and unacceptable kinds of warfare because the terrain that we carve out is strategically favorable." That may be part of the story, but it's more than just strategic—we want to define our means of warfare as ordinary and any other means as outside the bounds of humane behavior, less for practical advantage than to convince ourselves that our actions are moral and justified.
Don't misunderstand me. Bashar al-Assad is a monster, and he has already killed tens of thousands of Syrians. But he'll be no less a monster if he chooses to keep killing them with conventional weapons than if he turns to chemical weapons.