Hard to say. The history is murky and involve a whole mess of international conventions. https://en.wikipedia.org/wiki/Single_Convention_on_Narcotic_Drugs http

Hard to say. The history is murky and involve a whole mess of international conventions. https://en.wikipedia.org/wiki/Single_Convention_on_Narcotic_Drugs https://en.wikipedia.org/wiki/Single_Convention_on_Narcotic_... Seems to be the convention that brought cannabis into the fold.