The insane ruler of North Korea used his agent abroad and VX nerve agent to kill his half brother in Malaysia. It was the first recorded use of a weapon of mass destruction being used to kill a single man. Leave it to a NORK named Kim.
Various people of virtually no credibility have alleged that the crazy mad physician and current dictator of Syria used chemical weapons on his population or people fighting against his rule in the spirited attempt to make all things better in that hell on earth by adopting and using the tactics and strategy of the 7th century warlords who used islam to sweep aside all of the former kingdoms and peoples and religions of the middle east; albeit with one or two exceptions here and there.
Saddam is alleged to have had weapons of mass destruction and used them on his people. The people doing the alleging were later rounded up and branded as liars by the same people that brought us back pictures of thousands of dead marsh arabs and Kurds who were massacred in their towns and villages by chemical agents dropped on them by Iraqi forces.
We seem to be crossing over a bright line now and the world may rediscover just how hard it is to stuff this particular genie back in the bottle. Terrorists first used sarin gas against civilians in a terror attack in Tokyo's subways over 20 years ago.
As we reel along under the weight of an increasing campaign of urban terror that is increasingly poo-pooed by the intelligentsia and cognoscenti it may be time to dust off those gas masks and refamiliarize ourselves with the symptoms of the various forms of chemical warfare agents. Arguably, most of the more infantile training I got from the military involved some dork advising me that the guy standing next to me appeared to be going into seizures and spasms and what was I going to do about it. They never seemed to accept that I'd be doing the same dance with the same fate if I was indeed, standing right next to somebody who had been the victim of an invisible gas attack.