Protocol for the Prohibition of the Use of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare

In 1925, nations passed, under the auspices of the International Red Cross, the first treaty banning weapons of mass destruction, the Protocol for the Prohibition of the Use of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare. It is a short document, without much in the way of implementing protocols.

It is unclear how much effect it had on actual use; while such weapons were not widely used in World War II, that may have been more due to mutual deterrence, technology limitations, and tactical considerations than legal constraints.