The modern definition of the state refers to the notion of sovereignty and to the related notion of the national interest, which is accompanied by secret politics. Niccolò Machiavelli was the first thinker to advocate for the primacy of the national interest. He drew inspiration from the classic concept of arcana imperii (secrets of state) and his writings can be used to explain why the concept of the national interest has taken on a modern form and is inextricably linked to the mysterious dimension of politics. Machiavelli pointed out that power is accompanied by enforcement power and indescribable hypocrisy, and actions taken at the state level (lo stato) are unique and require protection. However, we now witness the disappearance of the mysterious dimension of politics. Information leaks, tape recordings, eavesdropping and candid photos cause public debates and lead to numerous political changes. In this situation, the concept of the national interest must be discussed again. The public justification for the national interest and concrete political solutions and goals implemented by the state could reduce citizens’ suspicion, which is fed on further leaks.