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

Machiavelli notes that a man will fear a prince who will execute him for disobedience, but he won't hate him. One example used by the author is Hannibal, whose soldiers revered him even though he was cruel leader. Rather than hating him, they had respect for his cruelty. According to Machiavelli, people expect to be punished for wrong doing, if they are not punished, they lose all respect forthe authority figure.