This research was written using an analytical-descriptive method and data collection was done through library and documentary methods and referring to Internet websites. It is developmental-applied in terms of its purpose and nature. In this article, an attempt has been made and the research goal has been to explain the strategic, defensive, geostrategic and geopolitical importance of the three islands in Iran's defensive and military doctrine. Also, by analyzing the historical and legal dimensions of the dispute over these islands, Iran's undisputed ownership and the closure of this dispute file are reflected. The main question of the research has been posed as follows: "To what extent is the strategic and geopolitical importance of the three islands and can the possibility of compromise and bargaining over these islands be considered included in Iran's foreign policy and security doctrine?" A temporary answer to this question has been proposed in the form of a research hypothesis as follows: "According to numerous historical and legal evidence, the three islands are an inseparable part of Iran's territorial integrity, and any exchange within the framework of diplomatic concessions will result in serious losses for Iran in terms of defense, hegemony over the Strait of Hormuz and the Persian Gulf, authority, prestige, and dimensions and components of defense and security."