Si vis pacem, para bellum

Si vis pacem, para bellum (Classical Latin: [siː wiːs ˈpaːkɛ̃ ˈparaː ˈbɛllʊ̃]) is a Latin adage translated as "If you want peace, prepare for war." The phrase is adapted from a statement found in Roman author Publius Flavius Vegetius Renatus's tract De Re Militari (fourth or fifth century AD), in which the actual phrasing is Igitur qui desiderat pacem, præparet bellum ("Therefore let him who desires peace prepare for war"). The idea which it conveys also appears in earlier works such as Plato's Nomoi (Laws).

Source: Wikipedia — Si vis pacem, para bellum (CC BY-SA 4.0)