U.S.-Iran relations have been complex and often tense since the 1979 Iranian Revolution, which led to the overthrow of the U.S.-backed Shah. The subsequent establishment of the Islamic Republic of Iran resulted in the severing of diplomatic ties and the U.S. imposing economic sanctions due to concerns over Iran's nuclear program and its support for groups considered terrorist organizations by the U.S. In recent years, efforts to negotiate a nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), have seen ups and downs. While the U.S. withdrew from the agreement in 2018 under the Trump administration, discussions have continued intermittently, reflecting ongoing geopolitical tensions in the Middle East.