
“Fortune, which has a great deal of power in other matters but especially in war, can bring about great changes in a situation through very slight forces.”
Sed fortuna, quae plurimum potest cum in reliquis rebus tum praecipue in bello, parvis momentis magnas rerum commutationes efficit; ut tum accidit.
The Civil War, Book III, 68; variant translation: "In war, events of importance are the result of trivial causes."