Pancho Villa received a copy of the laws of land warfare from an American general stationed just across the U.S. border. […] The Hague Conference of 1907 from which the rules in part derived was still fresh. The First World War had not yet broken out. [The] rules completely confounded the Mexican revolutionary general.
Villa “spent hours poring over it.” The Hague rules “interested and amused him hugely.” But then he turned sour. “What is this Hague Conference?” Villa asked. “Was there a representative of Mexico there?” Villa wanted to know. […]
Ultimately Villa concluded that it seemed “a funny thing” to make laws for war. “If you and I are having a fight in a cantina,” he told Reed, “we are not going to pull a little book out of our pockets and read over the rules.”
From “The Dismal History of the Laws of War” (pdf), in the UC Irvine Law Review.