All of us have a visceral, emotional reaction to the use of chemical weapons. It repulses us. Anyone who has seen the video footage of men, women and children writing in agony following the use of chemical weapons in Syria won't soon forget those images.
Yet there's a question that must be asked: why are we more offended by the killing of civilians with chemical weapons than we are by the slaughter of far greater numbers of civilians with conventional weapons? More to the point, why do we insist on calling chemicals weapons "weapons of mass destruction" when they are nothing of the sort? Historical evidence suggests that chemical weapons are actually not very good at killing people, and very rarely, if ever, cause "mass destruction".
There are three kinds of "weapons of mass destruction": nuclear, biological and chemical. Only the first one actually causes mass destruction, as humanity witnessed in Hiroshima and Nagasaki. The other two, as the American terrorism expert David C Rapoport said a few years ago, would be better referred to as "weapons of minimum destruction", since they're just not very good at destroying things or people in a war setting. (This is leaving aside the use of gas during the Final Solution, when it was deployed in an industrial fashion in a controlled environment and consequently had a devastatingly effective impact.)
Consider the use of chemical weapons during the First World War. This was the deadliest use of gas in a war setting in human history. And yet the impact of the gas was negligible in the broad sweep of human suffering during that conflict.
Killing people with gas was really hard work. Indeed, as Rapoport has pointed out, during the First World War "it took a ton of gas... to achieve a single enemy fatality". Why? Because "wind and sun regularly dissipated the lethality of the gases. Furthermore, those gassed were 10 to 12 times as likely to recover as those causalities produces by traditional weapons."
Such was the uselessness of chemical weapons relative to traditional weaponry that some soldiers actually preferred being attacked with gas rather than with guns or bombs. As two military observers wrote in 1918: "Instead of being the most horrible form of warfare, [chemical assault] is the most humane, because it disables far more than it kills, ie, it has a low fatality ratio."
In the most notorious modern instances of state use of chemical weapons, the number of fatalities have also been low relative to deaths caused by conventional firepower.
Saddam's gassing of the Kurds at the tailend of the Iran-Iraq War in 1988 is estimated to have caused 5,000 deaths - though it is very unclear how many of those deaths were caused by gas and how many were caused by the conventional firepower that was deployed against the Kurds at the same time. Even if all 5,000 were killed by gas, which is highly unlikely, that would still account for less than one per cent of the estimated 600,000 deaths caused by Saddam's side in the Iran-Iraq War.
In Syria, it is thought that 350 people have been killed by chemical weapons - that is just 0.35% of the 100,000 deaths so far in that hellish war.
There have only been a handful of instances in history when non-state groups have used so-called WMD, and they have not managed to cause much destruction at all. In Sri Lanka in 1990, the Tamil Tigers used chlorine gas against Sri Lankan soldiers who were guarding a fort. Sixty of the soldiers were injured, but none was killed. The Tigers' use of chemicals greatly angered their support base, who thought it was uncivilised, and so the Tigers never used chemicals again.
The most notorious use of "WMD" by a terrorist group was in Tokyo in 1995, when the Aum Shinryko religious cult released sarin gas on the underground. Yet even this attack, carried out by a cult that had numerous members with scientific degrees, access to laboratories and lots and lots of money, did not cause the "mass destruction" that the cult hoped for. Thirteen people were killed and 40 were seriously injured. Every one of the 13 fatalities had come into actual physical contact with the liquid form of the sarin left on the underground, showing that Aum Shinryko's hope that people would die by breathing in the sarin was completely dashed. More people were killed by the "conventional" bombs used on 7/7 in London.
Given that they do not cause mass destruction, why are chemical weapons referred to as WMD? Why are we encouraged to fear and hate these weapons far more than, say, Tomahawk missiles, even though the latter have been responsible for far greater levels of death and destruction? How can even nuke-owning countries like France and America get off on slamming Syria for allegedly using the non-WMD that is sarin gas?
It's largely about drawing a line between the civilised world (us) and the uncivilised world (them). The modern Western world, bereft of its old sense of mission and imperial righteousness, needs new ways to distinguish itself from the savages of the East and the South - and one of the key ways it does that today is through presenting their wars as uncivilised in contrast to our wars, which are apparently clean, legal, decent and definitely chemical-free.
The possession of chemical weapons has become one of the main markers of uncivilised behaviour in the 21st century, and thus the wickedness of such weapons is talked up, exaggerated, as a reminder of who is wicked and who is good in the modern world.
The great and terrible irony is that the conventional firepower used by Western armies under the auspices of destroying evil foreign states' WMD stashes - first in Iraq, and now possibly in Syria if France and America get their way - have killed infinitely more people than any sarin-waving dictator or terrorist could ever hope to.