Summary by Lewis G. Miller
In Chapter 12, Machiavelli begins a discussion on how Prince’s should organise their militaries. He begins this assessment by looking at Mercenaries. The whole chapter can be considered a strong critique of the use of mercenaries, where Machiavelli gives reason after reason as to why the Prince should avoid their use.
First among these is that they are motivated to defend you because of money, not honour or the love of their cities. In this regard, mercenaries will not defend you when you need them most, unlike troops which you have raised from your own cities.
The Commanders of these mercenary forces will either be brave or cowardly. In the case that they are brave, they will likely aim to supplant you as Prince. If they are cowardly, then they are unlikely to fight well against your enemies. Either way, you lose. Such commanders are responsible for changing the structure of armies to make them less efficient, and often fight each other in ways which avoid any bloodshed.
This problem was important in Machiavelli’s time, as many Italian states relied upon their services. The power and influence of mercenaries was, therefore, a particular problem for Machiavelli.
These problems are relevant today too. Central is the idea of control: If you control your army directly, and if they are loyal to you, then you have comparably less to worry about than if co-opt the army of someone else. This is because they are unlikely to serve anyone else, you can appoint new heads of their regiments and banish disloyal generals. In a world where outsourcing is an everyday reality, questions of loyalty and motive may still be important for people wanting the best job for their money.