First, there is the concern that Hank raises in his comment above. Incapacitating agents may be used more easily and less discriminately. Additionally, if these weapons are used instead of deadly force in some situations, combatants may act differently when they know their enemies will incapacitate them instead of kill them. Perhaps, the answer to the less discriminate use is, in part, to define circumstances in which this level of force can be used, similar in kind to restrictions on when police officers can use force or when an enemy soldier can be killed or injured. Whether or not would-be targets of the incapacitating agents will be more aggressive when they are at a lower risk of death is an interesting question, the answer to which could be suggested by how police encounters have changed since they began using tear gas, pepper spray, and tasers.

Second, for some chemical agents like fentanyl, the dosage necessary to incapacitate may be very close to the lethal dosage, resulting in unintended deaths, including civilian deaths. A low therapeutic index weakens one of the strongest arguments in favor of the military using these weapons, that they can be used in populated areas instead of lethal weapons that might kill bystanders. If a chemical weapon with a low therapeutic index is deployed in a crowded area, civilians will still die. This concern may be resolved with more input from scientists familiar with the chemical agents (as the editorial suggests).

Third, the incapacitating chemical agent may be misused to kill a person while he is unconscious, which is a violation of international humanitarian law. Breaches of humanitarian law are a more basic problem that is not unique to the context of incapacitating agents. Still, whether an amendment to the CWC to allow for military use would likely increase misuse should be part of the conversation about whether to amend. Perhaps one step toward resolving this problem would be to include provisions specific to how soldiers who are chemically incapacitated must be treated.

If incapacitating agents that are used appropriately can, in some instances, substitute for lethal force and avoid deaths, then I think the conversation should be about how the CWC and other laws can be structured to prevent overuse or misuse. Only if that goal were impossible, would an absolute ban on their use seem necessary to me.

Does non-deadly force get used more easily and less discriminately? “Stun them all; we’ll sort it out later.” On the other hand, is it as effective when those attacked know they can try to storm the users without fear of death? (I like to read some science fiction, but fear to cite it, but botho of these are raised in Lois McMaster Bujold’s Vorkosigan series, as the characters, from time to time, note differences between using stunners and (lethal) nerve disruptors.

On its face, non-lethal/permanently disabling weaponry seems to me better than the alternatives, but much would depend on the circumstances, though not, I think, specifically on whether it was a weapon targeted at the brain.