Yes, I understand what it's "official" use is and why armies including ours can "legally" use it, but when you drop it purposely on people, it's chemical warfare. Now I don't know what the Russians did, or didn't do, but the accusation was that they dropped it on ISIS fighters. If that is so, that's chemical warfare in my book.
No biggie, it'll go nuclear before it's all over, they know how to poke the bear, and they are poking every bear there is.