The Prince

In Chapter 13, Machiavelli warns against auxiliary troops—foreign soldiers borrowed from allies—calling them "useless and dangerous." Unlike mercenaries who fight poorly, auxiliaries fight well but serve their true master's interests, not yours. When they lose, you're ruined; when they win, you become their prisoner. Historical examples include Pope Julius II's reliance on Spanish forces and the Byzantine Emperor's fatal dependence on Turkish auxiliaries. Mixed armies combining your own forces with auxiliaries prove only marginally better, as divided loyalties undermine unity of command. This principle extends to modern organizational dynamics. Leaders face similar dilemmas when outsourcing critical functions or relying heavily on consultants. Over-dependence creates strategic vulnerability—companies that outsource core competencies often become prisoners of their service providers. Machiavelli's solution: build internal capability while using external resources strategically and temporarily. Sustainable power requires owning essential capabilities rather than borrowing them, because borrowed power ultimately serves the lender's interests, not your own.