Any country must buy precursors of chemical weapons without never build chem weapons. Because those are substances of wide use.
Well, but Iraq built and used chemical weapons and USA knew it.
Even without selling precursors, it's hypocrite support a regime who used those weapons, and they did it.
Although I guess it's perfectly legal and if it's not, it doesnt matter, because you can't judge/punish the strongest superpower of this world.
Laws can only to be applied to weaker subjects than who are judging.
I think it's not a nice thing from international laws point of view the fact of drop two nukes over civilians in Hiroshima and Nagasaki
.
But obviously no one can judge USA about it, because there is no a state stronger than USA in this planet.