This Day in International Law- September 25th

September 25, 1915: British uses poison gas for the first time, suffers defeat at the Battle of Loos 

By Chelsea Turner

On September 25, 1915, the British, in violation of international law, released poison gas in a battle against the Germans in Loos, Belgium. The British weren’t the first to use poison gas in World War I – the German army had deployed poison gas against the Russians in January of 1915 and against the French in May of that same year. The commander of the British Expeditionary Force, Sir John French, justified the use of poison gas against the Germans “owing to the repeated use by the enemy of asphyxiating gases in their attacks on our positions.”

Both the German and the British both ignored one important fact – that their countries had signed treaties prohibiting the use of poison gas in international hostilities. The first of these was the 1899 Hague Declaration Concerning Asphyxiating Gases, which prohibited the “diffusion of asphyxiating or deleterious gases” in international warfare. The second treaty outlawing the use of poison gas was the 1907 Hague Convention on Land Warfare, which declared the use of “poison or poisoned weapons” in hostilities as “especially forbidden.”

The British used poison gas throughout the entirety of World War I, Winston Churchill advocated for its use in World War II, and the country continued to develop and stockpile it up until 1956. And while poison gasses became symbolic of the horrors of World War I, the use of poison gas in hostilities has continued to occur. Most recently, in 2013, the UN released a report finding that “beyond a doubt” the Syrian government had committed the war crime of using Sarin gas against its own citizens.

Chelsea Turner is a J.D. Candidate at Berkeley Law. She is a student contributor for Travaux.