Iran, over the past four decades, lived through a state of continuous alert to defend itself against the threats surrounding it and targeting its national security. Over that period, Iran did not enjoy clear recognition of its legitimacy from the major powers, the United States in particular. This created ongoing anxiety and restricted Iran’s efforts of “preserving the regime”, which Ayatollah Khomeini made the highest duty. These circumstances had tangible effects on Iranian national security and its strategy. The article sees that the nuclear agreement might be the beginning of a new phase. Via the agreement, Iran feels it has gained the recognition of the international community, and acknowledgement of its demand for legitimacy. Most importantly for Iran, the agreement shifts it away from the obsession with security and stability, and encourages it to bring out the features of the “Iranian model” in the region. The paper also discusses the fears of neighboring states and Iran’s efforts to reassure them. The positions of the political currents and the power centers in Iran are also considered as well as their differences over the pluses and minuses of the agreement.