The Germans use nerve gas. German troops surprise Allied forces at Ypres, Belgium, attacking two French and Algerian colonial divisions with 168 tons of lethal chlorine gas. The first major German gas attack decimated the Allied lines, so France and Great Britain immediately began developing chemical weapons and gas masks. During their subsequent advance, the Germans flooded enemy trenches with another gas, called mustard, which was named “mustard” after the tragic events at Ypres. The use of gas suits and masks by soldiers on both sides ultimately thwarted the use of chemical weapons in warfare. During the First World War, a total of over 100,000 tons of chemical agents were used, causing injuries to approximately 500,000 soldiers and the deaths of 30,000. The 1925 Geneva Convention prohibited the use of chemical weapons in warfare, and World War II sides respected this agreement, primarily for reasons of military strategy. Since then, chemical weapons have been used only in a small number of conflicts, and always against enemies not wearing gas masks.
