Syria

[Lady's Human]

Assad gets away with killing his own people via chemical weapons and the world does nothing.

And his own people were also using chemical weapons in their attacks on government forces. They're all bad actors.

What happens when the next dictator decides to use an even stronger chemical weapon to achieve the same end? Chemicals don't exactly understand international borders; what happens if a chemical weapon - oops! - drifts over a border and kills people from a different country? Where does it end?

Sarin is about one of the nastiest agents to deal with. However, it's non-persistent, and is broken down rapidly by water and sunlight.

I'd go into a dissertation on the effects of various agents, but the reason NATO forces don't use them are twofold:

1) Nasty for your own troops to handle and deploy.

2) impossible to control, weather has more control over the agents than the deploying troops.

There are persistent agents, non-persistent agents, blood agents, blister agents, mustards, the possibilities are many.

As insane as Hafez Assad appears to be, however, he's not dumb enough to let Sarin drift into Israel.