What does the author claim that military leaders can learn from Hannibal?

Machiavelli compares two great military Hannibal and Scipio, and he notes that although Hannibal's army consisted of men of various races, his men were never rebellious because they feared their leader. Scipio's men, on the other hand, were renown for their mutiny and dissension. Machiavelli states, "I conclude that since men love as they themselves determine but fear as their ruler determines, a wise prince must rely upon what he and not others can control."

How leaders can use cruelty to gain the respect of their soilders ..