Fans of the NFL will be familiar with the unnecessary roughness rule; it’s one of those features of America’s most popular game that sometimes causes bemusement, even to those who consider themselves long-time devotees. In a game memorably described as ‘young men running around risking spinal injury’ or ‘an endless series of head-on collisions’, there is something rather charming about a rule that attempts–with only limited success–to circumscribe its mayhem.
I am reminded of that rule’s strictures as I observe the anguished reaction to the use of chemical weapons in the ongoing conflict in Syria. A ‘red line’–a moral one–has been crossed, and punishment for the offenders is in the offing. But I do not yet understand fully what marks this line out for us, how its boundaries are to be observed.
It cannot just be the associated violence or the loss of life. Conventional weapons also flay flesh, gouge out eyes, destroy limbs; they drive red-hot metal into your abdomen, your skull, tear out your intestines; they will kill your children just as effectively as chemical weapons will. Do chemical weapons cause more pain? Reading reports of children ‘writhing on the ground and foaming at the mouth’ might make one think so, but this is delusional. If your entrails are ripped out by the shrapnel from an artillery shell, and no aid is forthcoming, your death is very likely to be a prolonged, miserable affair. Moving on from guns and cannons, shells and bullets, how about a knife to the eye or a bayonet in the neck? (Ever heard that gurgling sound someone stabbed in the neck makes?) Are we against slow deaths and for quick ones? How slow is problematic? And why should that make a difference? And clearly, the loss of civilian life does not seem to bother too many; if the rationale for the positioning of the ‘red line’ is to be taken seriously, killing civilians with conventional weaponry–laser guided bombs? drones?–would be just fine.
You can ban the use of napalm but you cannot stop civilians burning to death when a high-explosive shell sets their house on fire. That same ban will not prevent children seeing their parents die in front of them, or parents their children. Being buried alive should sound like a pretty horrible death to us; that can easily be brought about by those conventional weapons whose use is approved of by our laws and morality.
Our civilization’s qualms about the use of chemical weapons betray a certain inconsistency: if the death of innocents and causing gratuitous pain to them is our central concern then all forms of armed warfare should constitute a ‘red line’ not to be crossed. But like the NFL and its endless concussions and spinal injuries, we like to keep the dogs of war handy, straining at their leashes, ready to run out and dispatch their prey, and reserve the right to turn up our delicate noses when they cross some arbitrary bounds of savagery.
War, apparently, is inevitable. We just don’t want to get our hands too dirty with it. We are a fastidious species.
Samir Chopra 
But – there is a precedent, well established, about chemical weapons. None of the other things you mentioned have a precedent. Technologists are fast at work on other ways to kill people, and ethicists are struggling to keep up. Recently, a UN official proposed a ban on roboticized killing machines – fully automatic killers. Presumably they would also kill with guns, but the idea of distancing conscience from killing is abhorrent to many. Your argument would draw the line – no where. I wouldn’t argue for war, necessarily, under these circumstances, and it’s clearly horrible that 100K people have died already in Syria, but the willingness to use banned weapons might be a marker of a deeper venality than the ordinary dictatorial venality.
By going to war, haven’t you already distanced conscience from killing? After all, your premise is that your political objective is worth the lives of real people. Isn’t this the rough ground for consequentialists for that very reason? How do you perform the calculus required and not look absurd in the process?
Walzer in Just and Unjust Wars has a very good discussion of just the question you raise. How do you ‘do’ morality and wage war?
It seems true, alas, that war is part of the human condition. Unfortunately. And we keep repeating the same mistakes that lead to it. Apropos the current situation, I can’t help thinking we’ve gone back to the 1930s. Back then, Italian forces used chemical weapons in North Africa, to the condemnation of the world. It didn’t stop them, much.