The conflict between the United States and Iran has a long history and each new president elected has his own way of dealing with this conflict. During the Trump administration, relations and conflict between the two countries appeared to be deteriorating. In this context, the study aims to determine the cause of the escalation of the conflict between the United States and Iran during Donald Trump administration. In researching this problem, this study uses qualitative research methods. The method used in this study is a qualitative descriptive method that describes phenomena that occur, such as activities, characteristics, relationships and further interprets the phenomenon as a condition or relationship that occurs or is ongoing. The data collection technique that the author uses in the preparation of this thesis is through library studies. Upon the research, the results pointed out, that the change of U.S. president from Barack Obama to Donald Trump and the policies taken contributed to changes in national interests and changes in U.S. position towards Iran, which in the end also led to a change in Iran's position towards the U.S.