Venice's manpower and mercenary trap

Venice's extensive commitments demanded more soldiers and sailors than its city-state population could supply. It therefore depended on hired German, Swiss, feudal, and other outside forces whose service rested heavily on pay. As trade income and military returns fell, that model became difficult to sustain across repeated wars and sieges. Professional troops do accept danger, but their willingness to fight cannot be treated as limitless devotion to a state that is no longer paying for a credible campaign. This manpower problem helps explain why Venice could possess famous fortifications yet lack the experienced core needed to resist France effectively.