According to machiavelli why is understanding the art of war an important concept for future and current leaders

According to Machiavelli, the main goal of those who attain power is to stay in power indefinitely. It is necessary thus to be prepared for anyone willing to attack you and try to take your power away from you. If you as a leader are not familiar with the art of war, then someone else who is familiar will have the upper hand and might remove you from power and take it for themselves.