Breaking News: US Missile Strikes Against Military Targets Inside Syria

[Anomalocaris]

Since WWI, gas has been viewed differently than other weapons.  As a kid in the 60s, I was aware of an 'old man' we frequently saw sitting outside his apartment as we went to the grocery store.  He was disabled, and had been since being gassed in WWI.  The lasting effects of gassing upon the survivors, and the indiscriminately lethal effects of it put it in a special category of armaments.

Additionally, in a theoretical orbit, restrictions on how warfare is conducted, if observed by both sides, will not affect the outcome.  WWII didn't see use of 'gas', but it was deployed.  There were even strong advocates for it's use.  US forces were injured by mustard gas in Italy, but the gas wasn't deployed by Germans or Italian forces, it was leaking from stores the US had sent to Italy, 'just in case'.

Also, President Roosevelt was under enormous pressure to approve the use of gas on at least one Japanese held island in the Pacific (IIRC, Iwo Jima), and it's hard to imagine a more 'perfect' situation for it's use (Japanese forces were dug in, and were definitely prepared to fight to the last man).  Still, Roosevelt, mindful of what happened in WWI would not approve it's use, 'even on Japanese soldiers' and subsequently suffered 20,000 marine fatalities in securing that island.

I would think any future use of gas by the US would irretrievably sully what those marines sacrificed in lieu of a 'cheap and easy' battlefield win with gas.

So gas is different.

I do find this a compelling argument that gives me pause.
While it seems almost insane to ignore the deaths of thousands of children from conventional weapons and freak out over the deaths of dozens of children from gas, it may be in humanities overall best interest to act this way. If everyone everywhere understands (including strongmen and theocrats) that any use of gas will be met with a fevered response, it will deter future use of such weapons.

However, another part of also understands that regular explosives are also "chemical" attacks. That's what C4 is. It seems to me that we may be using a primal fear of poison to ignore the real consequences of explosives thus giving murderers a way to kill people that is somehow acceptable. As far as I can tell, poison gas has not proven itself to be more deadly in armed conflict than regular weapons (I could be wrong here).

I would be very interested in hearing more opinions on this subject. Is gas a special case where we should ignore our normal diplomatic responses and attack regardless?

The reason why gas was never used during WWII by either side is much less honorable than any willingness to incur casualties to honor an moral obligation.

Both Germany and the western allies were each in the dark regarding how advanced chemical weapon research really was on the other side.  Both the western allies and the Germans were convinced the otherside's research was substantially more advanced their own.  Hence both sides feared unleashing chemical warfare because they feared it is a form of warfare that, once started, would give their enemies a great advantage.

As war progressed the defeats suffered by the German army on the eastern front and the massive loss of equipment also caused the German army to become increasingly vulnerable to chemical warfare. By 1944 when German military situation became critical, using chemical weapons defensively become no longer an option because there were no effective gas masks for horses and the German army by this stage were primarily reliant on horses for most of military transport.

The Japanese did unleash chemical warfare in china, but dreaded unleashing chemical warfare against the western allies because they were certain allied chemical weapon research was far more advanced.  They were mostly right.

If the war had not been ended by Hiroshima and Nagasaki, American plans called for a prepatory amphibious invasion of Japanese southern home islands in late 1945 and main invasion of the kento plains and Tokyo in early 1946 under the code names operations Olympic and corona.  

At that time war with Germany was over, State of Japanese checmical warfare development was better known, and there was no longer fear of the enemy having more advanced chemical weapons than the allies.   So it was, as not declassified until the 1990s, that American operational plans for operation corona involve massive use of chemical weapon against Japanese civilian as well as military targets as part of the pre-invasion softening up and as tactical measure during the invasion no subsequent land operation.  Incidentally, in a preview of agent orange, American chemical weapon intended for use against Japan also included agents to destroy food crop in order to worsen the food supply situation in Japan.

So the story of how America sacrificed to void using chemical weapon is pleasant piece of balony

America had every intention of using it, on a massive scale, against civilians, but were robbed of the opportunity by early end to the war.