As I remember my military history or briefing on the Geneva Convention, this came about because of the extreme wounds and death agony caused by using soft lead bullets. When you see battlefield pictures from the Civil War you'll see dead men with their shirts pulled up. They were looking to see if they were gut shot, a horrible way to die. After the war there were thousands of men with lost limbs; soft lead completely blew the bone apart when they hit it. Although war in and of itself is not humane, they always end and there are always survivors. The intent was/is to reduce the amount of suffering that continued after the last bullet was fired.
