Been going through this a bit. Definitely worth at least a skim --
http://www.digitalattic.org/home/war/vegetius/
He, therefore, who desires peace, should prepare for war. He who aspires to victory, should spare no pains to form his soldiers. And he who hopes for success, should fight on principle, not chance. No one dares to offend or insult a power of known superiority in action.
It's where "Si vis pacem, para bellum" originated -- if you want peace, prepare for war. Etc.