Cite?
https://en.wikipedia.org/wiki/Si_vis_pacem,_para_bellum
“The phrase Si vis pacem, para bellum is adapted from a statement found in Latin author Publius Flavius Vegetius Renatus’s tract De Re Militari (4th or 5th century AD), in which the actual phrasing is Igitur qui desiderat pacem, praeparet bellum (”Therefore he who desires peace, let him prepare war.”).
The idea which it conveys also appears in earlier works such as Plato’s Nomoi (Laws) and the Chinese Shi Ji. The phrase presents the counter-intuitive insight that the conditions of peace are often preserved by a readiness to make war when necessitated. “
But I am on a first name basis with Murphy, who elegantly stated, and I quote:
"When in doubt, empty the magazine"