The US usage and supply of chemical weapons seems to go back as far as you are prepared to investigate. For the current situation in the Middle East there is a good case to be made that based on OPCW findings it was either Turkish backed or US backed rebels that used chlorine gas and Sarin gas to frame Assad, who has since been cleared despite that important part receiving practically no coverage in Western media.
That gas can be traced back to Donald Rumsveld when he worked as an economic hitman in the Chemical Industry, and supplied it to Sadam Hussein, himself a CIA man at the time, for use against Iran in the Iran/Iraq war they were plotting.
I love this above clip from CNN most of all because its CNN of all people, and because of Rumsvelds surprise that a CIA embedded news agency would rumble him on his earlier closed door meetings. He thinks fast on his feet though. They subsequently brought their man down but are still trying to nail Iran any way they can. Iran was toppled once when they brought down Mosedesch but has since appeared to have developed an iron resolve never to fall to foreign invaders again.
Post 9/11 during the "War on Terror" the US showed in all sorts of ways that it is in fact the real terror. Despite that, I was still slightly surprised when in 2003 they were caught using Depleted Uranium, considering the WMDs fiasco.
White phosphorus is the modern banned weapon of choice for the US military, its even more horrible but doesn't require large scale "boots on the ground" deployment (or if they wish to conceal such deployment).
Also there are loophole's in its procurement meaning it's not illegal to own if not used in open battle against civilians in populated areas.
It is being used in most of the US involved battles, including against civilians, region wide, so unless some shadowy force is following the US military undetected, and burning the civilians to frame the US in over a hundred seperate cases going back years, then the US is guilty.
Here is Amnesty Internationals findings:
https://www.amnesty.org.uk/press-releases/syria-us-led-coalitions-use-white-phosphorus-raqqa-may-be-war-crime-new-analysis
And from Human Rights Watch:
https://www.hrw.org/news/2017/06/14/iraq/syria-danger-us-white-phosphorus
The world's press are picking up on it too. Here is an assortment of articles, including MSM articles surpringly, but those outlets won't be permitted to run such reports in the future so read them while you still can.
https://www.nytimes.com/2017/06/10/world/middleeast/raqqa-syria-white-phosphorus.html
https://globalnews.ca/news/4436862/syria-white-phosphorus-us-russia/amp/
https://www.middleeasteye.net/news/moscow-accuses-us-using-banned-white-phosphorous-syria-1249368703
https://www.washingtonpost.com/news/checkpoint/wp/2017/06/09/u-s-led-forces-appear-to-be-using-white-phosphorous-in-populated-areas-in-iraq-and-syria/?noredirect=on&utm_term=.4996c30ecfd4
https://www.presstv.com/Detail/2018/10/13/576883/USled-warplanes-drop-white-phosphorus-bombs-in-eastern-Syria-Report
https://sputniknews.com/amp/world/201810141068878088-syria-un-investigation-use-white-phosphorus-coalition-forces/
