Bellum se ipsum alet

The Latin phrase bellum se ipsum alet (English: The war will feed itself) or bellum se ipsum alit (English: The war feeds itself, French: La guerre doit se nourrir elle-même), and its German rendering Der Krieg ernährt den Krieg describe the military strategy of feeding and funding armies primarily with the resources of occupied territories. The phrase, coined by Ancient Roman statesman Cato the Elder, is primarily associated with the Thirty Years' War (1618–1648).

The phrase bellum se ipsum alit was first mentioned in Ab urbe condita libri XXXIV,9,12, written by Roman historian Titus Livius (Livy) (59 BC-17 AD), who attributed it to Cato Marcus Porcius ("the Elder", 234–149 BC), a statesman in Ancient Rome. According to Livy, Cato in 195 BC used the phrase during the conquest of Hispania when he refused to buy additional supplies for his army in Iberia (Hispania, modern Spain and Portugal).

The slogan became prominent in reference to the Thirty Years' War. Friedrich Schiller in his retrospect, semi-historical drama Wallenstein (I/2, The Piccolomini), has Johann Ludwig Hektor von Isolani, a general in Albrecht von Wallenstein's army, say these words in a conversation with other commanders:

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