How the strength of all principalities should be measured
A way to judge the strength of a prince is to determine whether he can stand on the power of his own army or must rely on the help of others. A prince who can meet any enemy on the battlefield is considered self-sufficient; a prince that must rely on fortifications or on the help of others is not. Machiavelli uses the German cities as examples of well-prepared fortifications, capable of withstanding a siege for a year. Such preparations are necessary, and Machiavelli advises the prince that is not self-sufficient to provide for such measures. A well-fortified city will not be a target of attack and even if it is, most armies cannot engage in a siege for that long a time.
A wise prince must also know how to keep up the determination of his citizens during a siege. He can use several tactics, such as giving them hope, warning them of the cruelty of their attackers, taking strong action against dissenters, and directing their anger against the enemy. Since the enemy most certainly destroys the surrounding countryside of a fortified city, a prince can rely on the loyalty of his subjects whose properties have been damaged. Machiavelli writes, "It is the nature of men to feel as much bound by the favors they do as by those they receive." Chapter 10, pg. 43 As long as the city is properly defended and has enough food, a wise prince can withstand any siege.
