Evidence supporting my point on mustard gas being very bad for immune system and other issues, too
https://www.ncbi.nlm.nih.gov/books/NBK236055/https://www.ncbi.nlm.nih.gov/pubmed/16961503not only from what *older relatives and acquaintances told me* about seeing their comrades die off after the war and the psychological aspects of that
but the weapons leave a very large number of men with long term compromised immune systems
as we've seen with the awful mix of HIV, syphilis and Tuberculosis in some poor souls, having a lot of folk with weakened immune systems is a very bad problem for us
all.
you may win the war...and lose far more from a pandemic afterwards.
War sucks.
Chemical weapons proved not very efficient, compared to plain old HE and shrapnel in terms of casualties etc, but the psychological effects were veyr bad.
and post WW2, a lot of effort went into developing systems/training that meant that Weapons of mass Destruction were much less effective against suitable trained/equipped troops
however, one of the biggest secrets of the Cold War era wasn't the actual weapons per se, it was their delivery systems and methods to make them more effective which actually took a lot more money and effort than basic weapon design
Some US military officers after realising how deadly biological weapons had gotten thanks to these "innovations" (see weapon tests in the Pacific late 1960s), had had enough, and put pressure on the wahoos, and thus Nixon banned bio-chem research (though alas, some of the covert agencies still dabbled in that madness and likely continue to do so)
anyway
I'd expect to see Charis' enemies possibly try to develop such
they aren't exactly moral or sane, are they? Sigh
Chemical weapons are not much use as a naval vs naval weapon
but a "dynamite gun" would be a perfect weapon for hurling containers of poison or pathogens at ports
quiet, very large volume, projectile suffers little shock/heat, large calibre
Safehold will surely provide a few potential plant/animal based chemicals of use
and, the Proscriptions themselves, by saying "what does what", may give ideas, and the clergy aren't exactly above waiving exceptions....
"heroic warfare" didn't work too well against Charis, so their enemies will likely resort to terrorism, again
it's a problem that when you defeat an enemy's conventional military, but cannot come to a reasonable peace afterwards, that events and hotheads will push things to irregular and increasingly ugly violence
Britain vs Germany WW1
and Union vs South in US Civil War
both sides in those conflicts came to reasonable but troubled peace and many tried to avoid atrocities during the fighting
but thankfully the problems in decade afterwards weren't as bad as say, Iraq
as Teddy Roosevelt believed, allowing enemies to save face in defeat prevents resentments that flare up into more violence years later
i.e., French Revanchism post WW1 set the stage for WW2
and alas, Lincoln got murdered before he could implement his far more benign "olive branch" policy for the South which would have avoided a lot of the lingering bitterness that did occur in the face of punitive, greedy and dumb behaviour under Grant's Administration
Alas, Safehold has two bitter Emperors and an increasingly malign junta who don't
want a reasonable peace.
During the 1920s, Germany engaged in a highly covert chemical weapons project, using pesticides/herbicides as a cover and such developed chemicals to help provide funding
that resulted in ZyklonB and Sarin
and those involved after WW2 got put to work by the British and developed V and VX nerve gas.
So I'd expect covert projects set up most like by Desnair to develop chemical weapons
The Law of Unintended Consequence....
just building bigger and better warships or aircraft etc sometimes had rather odd knock ons in real life