if you want peace, prepare for war

Calque of Latin sī vīs pācem, parā bellum, an adage adapted from a statement found in 4th century AD Roman author Vegetius's tract De re militari, in which the actual phrasing is igitur quī dēsīderat pācem, praeparet bellum (“therefore let him who desires peace prepare for war”).

if you want peace, prepare for war

1. Visibly preparing for a fight can deter one's enemies from opening hostilities, by not giving the appearance of an easy target.

• balance of terror
• deterrence
• peace through strength
• make love, not war