Countless new weapons introduced in the history of warfare, from the crossbow to firearms to drones today, have met with their share of condemnation as unfair and immoral. And in nearly every case, this initial condemnation has slowly turned to acquiescence as the new contrivance is grudgingly accepted as part of the “conventional” armory humanity has to endure when conflict erupts.
Not so with chemical weapons. The taboo was broken more than it was honored early on, but today stands out as one of the most successful efforts to curtail the horrors of war. The combination over time of moral argument, repeated international agreements, some fortunate timing, and—perhaps most important—a tradition of nonuse, have by now endowed chemical weapons with an almost unique status. And looking at how it came about has lessons for how violence-prevention measures have and might in future take hold.
Various rudimentary forms of what could be called chemical weapons, like the use of choking smoke in sieges, always dotted the face of war. But it wasn’t until the 20th century’s combination of industrialized warfare and chemical science that the systematic use of poison gas arrived on the battlefield.
By the time it did, in World War I, it was already technically against the rules. The Hague Declaration of 1899, an important treaty to codify the laws of modern warfare, had banned gas shells when such weapons were still just a potential threat. Poisoning soldiers had long been considered an illegitimate tactic in battle, and chemical weapons seemed broadly to fall in this category. But delegates to the Hague Conference didn't seem to place an inordinate amount of importance on the topic: It was a weapon that had not even been developed, so nations were not giving up anything yet of importance.
The ban was obliterated in World War I, and accusations of who violated the Hague Declaration were traded as part of the war of propaganda. In 1915, the Germans began placing cylinders filled with toxic chlorine gas along the front, then opening them when wind conditions were favorable. Eventually both sides in the conflict were firing shells filled with chemical agents like mustard gas and phosgene.
The shock of being attacked via this new method of destruction was memorably captured in the war poet Wilfred Owen's "Dulce et Decorum Est":
...someone still was yelling out and stumbling,
And flound'ring like a man in fire or lime.
Dim, through the misty panes and thick green light,
As under a green sea, I saw him drowning.
In all my dreams, before my helpless sight,
He plunges at me, guttering, choking, drowning...