The worrying global lessons from Syria chemical attack
In terms of raw casualty numbers, Tuesday's apparent nerve gas attack near the Syrian city of Khan Sheikhoun - believed to have killed at least 70 - should hardly be significant against the backdrop of a war that has left hundreds of thousands of people dead.
But that was never the point of chemical weapons. Since European powers first used them over a century ago at the height of World War I, they have held a psychological and political shock value in many ways out of proportion to their physical or military effect. Alongside the threat of biological warfare, they hold a very distinct horror.
In the trenches of World War I, doctors noted that the paralysing fear of a gas attack often exceeded that of conventional artillery and bombs, even though the latter killed many more people.