In 1972, the U.S. signed the Biological and Toxic Weapons Convention, which banned the "development, production and stockpiling of microbes or their poisonous products except in amounts necessary for protective and peaceful research." By 1996, 137 countries had signed the treaty. But was this this the first attempt at establishing rules for 'humane warfare'? No, antiquity beat us to it, although they - also - often did not adhere to their own rules. The Brahmanic Laws of Manu, a Hindu treatise on statecraft dating back to the 5th Century BC, forbids the use of arrows tipped with fire or poison, but advises poisoning food and water. Kautilya's Arthashastra, one of the world's earliest treatises on war, advocates surprise night raids and offers recipes for toxic smokes and plague-generating toxins, but it also urges princes to exercise restraint and win the hearts and minds of their foes.
