The USA had plenty.
The could make, or have secretly made more.
There are too many small batch style chemical plants all over the country to believe any different. The list of things possible to make is completely unlimited. There are very few legitimate reasons to store phosgene gas, and yet it’s made and stored all over the country.
They might be a little dodgy to move that far away, but like so many things, it’s possible.
True. It's trivial to make new stuff.