The border position of a state can play an influential role in shaping its foreign relations. Access to waterways, commercial areas, and transportation routes are among the things that affect the geographical importance of a region in terms of borders and politics, and this issue is more important in sensitive international situations such as wars in which the countries involved each seek their own influence and interests. Iran enjoyed such a position during World War I and was the focus of the Allied (England-Russia) and Allied (Ottoman-Germany) governments. The study of Iran's border position in the Persian Gulf and its role in Germany's approach to this country during World War I is the subject of this research. The research method is descriptive-analytical. The achievements of this research show that Iran's land and water borders through the Persian Gulf, Arvand River, and proximity to Kuwait and Iraq due to the Berlin-Baghdad railway were among the reasons for Germany's economic and political interest in Iran. Also, proximity to Afghanistan is another reason for Germany's political presence in Iran during World War I.