One of the popular memes coming out of this Syria debacle is an assertion that there is no difference between conventional and chemical weapons. I’ve yet to see someone explain what the Just War Theory response on this is (granted I don’t follow this stuff anymore). So I figure I will just take a stab at it.
In the Just War literature, it is held that, unlike conventional weapons, chemical weapons are inherently indiscriminate. In war, non-combatants (civilians) are supposed to have immunity from attack. This requires at least two things of a war-maker. First, it requires that they not target non-combatants. Second, it requires that they not carry out attacks in indiscriminate ways, i.e. in ways that do not discriminate between non-combatants and combatants.
So you can’t, for instance, just nuke an entire city and say “well I didn’t target any non-combatants in particular, so I have not violated any Just War principles.” This wont fly because nuking a city, even one where you know combatants are at, is a totally indiscriminate attack.
Does that mean you can’t ever attack combatants if it would also kill non-combatants? Well no. The doctrine of double effect permits that, if you are targeting combatants, you are not necessarily culpable for the collateral and unintended deaths of non-combatants. If you think hard here, you can see a little tension between the prohibition on indiscriminate attacks and this permission of collateral damage. That tension is worked out fuzzily through the principle of proportionality. Some undesired non-combatant deaths are permitted in a targeted attack on combatants, but not too many.
In any case, on the Syria question, there is a substantive difference between chemical and conventional weapons. Chemical weapons, when unleashed in a city like this, are inherently indiscriminate because you cannot target them. By its very nature, chemical gas doesn’t just go towards some specific target. On the other hand, conventional weapons aren’t inherently indiscriminate. A gun for instance can be very discriminate: you can snipe a specific person dead with one. Bombs can also be discriminate and targeted, though less so than guns, triggering the proportionality considerations described above.
Of course, I presume that the Syrian regime hasn’t exactly been using its conventional weapons discriminately anyways. If that’s the case, then it is not clear what the difference is between using munitions indiscriminately (or even lobbing them discriminately at non-combatants) and using inherently indiscriminate chemical weapons. And so in that sense, it could be that the use of chemical weapons is not meaningfully different from prior Syrian actions. But that’s different from saying chemical and conventional weapons are the same.
To be sure, all of this depends on how much weight you put on this Just War canon. If you are a pacifist, you can say that both indiscriminate and discriminate weapons are equally wrong because some other principle (i.e. that they are objects of killing) overrides any other distinctions you might draw between them. In that case though, it is not that there is no difference between the two weapons, just that their differences are not determinative of anything within your war ethics framework. And if that’s all that’s going on, then we are really just back to a bare normative debate on the contours of military ethics, and the whole “chemical and conventional weapons are the same” thing is a question-begging distraction.
Also, for whatever little it’s worth as someone who doesn’t do this side of things anymore, I oppose attacking Syria.