Machiavelli's "The Prince" remains a textbook for leadership after five centuries because he knew what a leader needed to be successful.
He writes a leader who "is strong enough, if occasion demands, to stand alone" and "has a strong city, and who does not make himself hated, can not be attacked, or should he be so, his assailant will come badly off."
That strength comes from inspiring loyalty from one's subordinates and treating them the way you wish to be treated. For this to happen, a leader "must lay solid foundations, since otherwise he will be inevitably destroyed."
For a nation, he says the main foundation is "good laws and good arms," but that one "cannot have the former without the latter, and where you have the latter, one is likely to have the former."
Machiavelli also addresses the use of mercenaries in this passage. He firmly believes that a nation that depends on its own people to defend itself will always be successful, while a nation that relies on mercenaries will "have nothing but loss."
The word "Machiavellian" has become shorthand for evil, cunning and unscupulous behavior, but in this selection, Machiavelli comes off as someone making good sense by making the almost too obvious conclusion that leaders must have the loyalty of their underlings and that justice and fair play is the best way to achieve this. Treat them badly and make decisions not in their best interests, and a leader is doomed to fail.
The person who has to be bribed or coerced into obedience is not likely to be a person who can be counted on when the going gets tough. Every human ultimately acts out of self-interest, but loyalty usually comes from a belief that the leader you put your faith in is someone who is worthy of trust, makes sound decisions, is consistent and fair, possesses the skills to succeed and strives to instill them in his subordinates.
Machiavelli understood this. Cunning is useful at times, but it is no substitute for the principles of sound leadership.