Si vis pacem, para bellum

The phrase is adapted from a statement found in Roman author Publius Flavius Vegetius Renatus's tract Dē Rē Mīlitārī (fourth or fifth century AD), in which the actual phrasing is Igitur quī dēsīderat pācem, præparet bellum ("Therefore let him who desires peace prepare for war").

[5] Whatever the source, the adage has become a living vocabulary item itself, used in the production of different ideas in a number of languages.

For example, in 1790 during his first annual address to a joint session of Congress, George Washington stated "To be prepared for war is one of the most effectual means of preserving peace.

"[6] For example, historian Louis Antoine Fauvelet de Bourrienne made reference to the foreign policy of Napoleon Bonaparte:[7] In the United States, the National Arbitration and Peace Congress of 1907, presided over by Andrew Carnegie said: "If you want peace, make war."

The pacifism that opposed the world wars traced its lineage to Barthélemy Prosper Enfantin, an early French socialist and one of the founders of Saint-Simonianism.