When Obama was president, the “red line” he drew for the Syrian regime was the use of weapons of mass destruction, specifically chemical weapons. President Trump has also embraced the red line, asserting that Syria has gone “beyond a red line” with its recent use of chemical weapons. Trump has said that this attack changed his attitude towards Syria and Assad. Presumably the slaughter of civilians with conventional weapons did not cross the red line or impact his attitude very strongly. Those of a cynical bent might contend that the distinction between conventional and chemical weapons is accepted because it grants politicians the space needed to tolerate slaughter while being able to create the appearance of a moral stance. This moral stance is, of course, the condemnation of chemical weapons.
As I wrote in 2013, this red line policy involving chemical weapons seems to amounted to saying “we do not like that you are slaughtering people, but as long as you use conventional weapons…well, we will not do much beyond condemning you.” This leads to the question I addressed then, which is the question of whether chemical weapons are morally worse than conventional weapons.
Chemical weapons are clearly perceived as being worse than conventional weapons and their use in Syria has resulted in a level of outrage that the conventional killing has not. Some of the reasons for this perception are rooted in history.
World War I one saw the first large scale deployment of chemical weapons. While conventional artillery and machine guns did the bulk of the killing, gas attacks were regarded with a special horror. One reason was that the effects of gas tended to be rather awful, even compared to the wounds that could be inflicted by conventional weapons. This helped establish the feeling that chemical weapons are especially horrific and worse than conventional weapons.
There is also the ancient view that the use of poison is inherently evil or at least cowardly. After all, poison allows one to kill in secret and without taking the risk of facing an opponent in combat. In historical accounts and in fiction, poisoners are typically cast as villains. One excellent example of this is the use of poison in Shakespeare’s Hamlet. Even in games, such as Dungeons & Dragons, the use of poison is regarded as an inherently evil act. In contrast, killing someone with a sword or gun can be morally acceptable or even heroic. This view of poison as cowardly and evil seems to have infected the view of chemical weapons. This makes sense given that they are poisons.
Finally, there is the association of poison gas with the Nazi concentration camps. This connection has served to cement the connection of chemical weapons with evil. While these explanations are psychological interesting, they do not resolve the question of whether chemical weapons are morally worse than conventional weapons. It is to this issue that I now turn.
One good reason to regard chemical weapons as worse than conventional weapons is that they typically do not merely kill—they inflict terrible suffering. The basis of the difference is the principle that while killing is morally wrong, the method of killing is morally relevant to its wrongness. As such, the greater suffering inflicted by chemical weapons makes them morally worse than conventional weapons.
There are three counters to this. The first is that conventional weapons, such as bombs and artillery, can inflict horrific wounds matching the suffering inflicted by chemical weapons.
The second is that chemical weapons can be designed so that they kill quickly and with minimal suffering. An analogy can be drawn to capital punishment: lethal injection is regarded as morally superior to more conventional modes of execution such as hanging and firing squad. If the moral distinction is based on the suffering of the targets, then these chemical weapons would be morally superior to conventional weapons. Horrific chemical weapons would, of course, be worse than less horrific conventional (or chemical) weapons. As such, being a chemical weapon does not make a weapon worse, the suffering it inflicts is what matters morally.
The third is that wrongfully harming people with conventional weapons is still evil. Even if it is assumed that chemical weapons are worse in terms of the suffering they cause, the moral red line should be the killing of people rather than killing them with chemical weapons. This is because the distinction between not killing people and killing them is greater than the distinction between killing people with conventional weapons and killing them with chemical weapons. For example, having soldiers kill everyone in a village using their rifles seems to be as morally wrong as using poison gas to kill everyone. The result is the same: mass murder.
In addition to supposedly causing more suffering than conventional weapons, chemical weapons are said to be worse because they are often indiscriminate and persistent. For example, a chemical weapon deployed as a gas can easily drift and spread into areas outside of the desired target and remain dangerous for some time after the initial attack. As such, chemical weapons are worse than conventional weapons because they harm and kill those who were not the intended targets.
The obvious counter to his is to note that conventional weapons can also be indiscriminate or persistent. While bombs and artillery shells are accurate, they do still result in unintended causalities. They can also be used indiscriminately. Land mines present an excellent example of a conventional weapon that is both indiscriminate and persistent. Chemical weapons could be designed to have the same level of discrimination as conventional area-of-effect weapons (like bombs) and to be non-persistent (losing lethality rapidly). As such, it is discrimination and persistence that matter rather than the composition of the weapon.
While specific chemical weapons are worse than specific conventional weapons, chemical weapons are not inherently morally worse than conventional weapons. In fact, the claim of a moral distinction between conventional and chemical weapons can have terrible consequences: it allows a moral space in which to tolerate murder while maintaining the delusion of taking a meaningful moral stance.