"A prince never lacks legitimate reasons to break his promise"

The quote implies that a prince, or any leader with power, constantly has justifiable reasons to go back on their word or break a promise. Machiavelli is suggesting that in the pursuit of power and preserving control, leaders may need to prioritize usefulness over principles and morality. This quote aligns with Machiavelli's belief that a leader's main goal is to preserve their position of authority, even if it implies being sly or disregarding their pledges.