He addressed that in the article really well. He argues modern, well trained, armies that constantly move with devolved command structures can't effectively use

He addressed that in the article really well. He argues modern, well trained, armies that constantly move with devolved command structures can't effectively use chemical weapons, and on top of that if fighting against a comparable opponent chemical weapon protection is cheap. Even when under existential threat those type of armies haven't used them. Temporarily denying an area doesn't work with a mobile army, you might deny yourself an opening or you might not even know where your units are. But poorly trained armies, with no independent command because of the coup potential can kind of use them as they get into 'static' fights, and have done, i.e. Iraq and Syria. It really is an excellent article, though long, I would recommend reading it. And it really drives the point home that the idea we got civilized and banned them is a fuzzy PR lie we tell ourselves.