Who should a prince have as a friend to maintain a strong army?

From Chapter III (if your question pertains to a different chapter, please advise).

In this way you have enemies in all those whom you have injured in seizing that principality, and you are not able to keep those friends who put you there because of your not being able to satisfy them in the way they expected, and you cannot take strong measures against them, feeling bound to them. For, although one may be very strong in armed forces, yet in entering a province one has always need of the goodwill of the natives.