Machiavelli's the Prince

In chapter 21 Machiavelli writes about how a leader should bear himself so as to acquire reputation. He gives an example of a Spanish king who in the beginning of his reign attacked Granada. The king was able to keep his barons occupied with the war abroad while he built his reputation at home, leading to increased influence over his subjects. Machiavelli also asserts it is important for leaders to make their allegiances know in times of conflict. If two powers of equal strength as yourself are engaged in conflict and one is asking for help while the other is asking you to remain neutral you must always declare your allegiance one way or another and never remain neutral. A true ally will not ask you to remain neutral but will ask you to declare your allegiance openly. By remaining neutral you "will gain neither favor nor fame" no matter who prevails. If the powers engaged in the conflict are both weaker than you it is even more imperative to declare a side. A leader must also be sure to never join with a power stronger than yours unless it is an absolute necessity.

In chapter 23 Machiavelli cautions leaders to be careful who their friends are and to be wary of flatterers. It is important for a leader to surround himself with subjects who are given a certain discretion to speak freely on matters of which the leaders requests their opinion. It is equally important for leaders to listen to their advisers but still be able to digest the information they are given and make a decision that is their own. These same advisors should also be made to understand that when their advice is not solicited they should remain quiet.

...