#nerve gas while not actually used in wwii did carry a lot of weight just via the fear/threat of its use

[quixoticanarchy]

Because my latest accidental interest is chemical weapons, and because all my interests end up infected with a Tolkien angle, I present to you this: the Nazgûl attacks as interpreted as a form of chemical warfare.

This lines up well both with the Nazgûl ability to inflict fear on a mass scale and with the impacts of the Black Breath. People don't necessarily know what they're facing or what's happening to them, but both the experience and even the threat of it are terrifying. It also allows the obvious evocation of WWI gas warfare, though not, say, accompanied by the physical effects of chlorine or mustard. The Black Breath has both psychological and physiological effects which require medical treatment, and this description I think could be applied essentially unchanged to instances of chemical warfare:

At length even the stout-hearted would fling themselves to the ground as the hidden menace passed over them, or they would stand, letting their weapons fall from nerveless hands while into their minds a blackness came, and they thought no more of war, but only of hiding and of crawling, and of death.

I also think it would be fun if athelas (which treats the Black Breath) was a member of the nightshade family (which includes sources of natural atropine, which can treat the effects of exposure to certain chemical agents). This would put the Black Breath in the second generation of chemical agents, maybe a type of organophosphate nerve gas