War persists because nations must be fed with blood
 
Writing about the Aztec sacrificial ritual, Jacques Soustelle states that to keep the sun moving in its course so that darkness should not overwhelm the world, it was necessary to "feed it ever day with its food," the precious water, human blood. Looking at the warriors who had fallen around him during the First World war, French soldier J. Saleilles wondered whether the "gift of blood" was not the "supernatural source of the renewal of life which must e given to our country."

Nations are conceived as actual bodies (just like the sun god) that must be fed with blood in order to keep them alive. This is why war persists: nations are hungry for blood.