In the long ago and far away, I was tasked to go to Nuclear, Chemical, and Biological warfare school. I graduated first in my class. I also came away with knowledge of the effects of biological and chemical agents that most people have never thought about. This isn't particularly secret.
The news article linked above mentions that North Korea has the world's 3rd largest stockpile of chemical weapons. Couple that with the capability to launch a missile even the 800 miles between North Korea and Tokyo and the nascent nuclear program North Korea has pales by comparison.
VX, in quantities as small as 10mg, is fatal. There's some treatment, but you would have to be quick, and in the event of a mass attack, all facilities would be overwhelmed. This is essentially an organophosphate pesticide that works on mammals.
Here's the CDC factsheet.
We have been warned by the death of Kim Jong Nam. The risk that North Korea represents is now something that China, the U.S., and the Japanese should not continue to ignore.
This is either an edited video or a very high dose exposure, because the response happens very quickly. Taken sometime in the early 1960s, I remember seeing this footage. You might want to skip this, you might not, it's out there on YouTube.
Srebrenica's not simply another reminder of man's inhumanity to man, but how intelligent people can always come up with intelligent reasons to do nothing.