Abstract: Since Donald Trump has come into office as president of the United States, the US foreign policy toward Iran has undergone major changes, which has been prominently manifested in such actions as endorsing hardline advocates who are against Iran to important political offices, withdrawing from the Joint Comprehensive Plan of Action (JCPOA), and imposing high economic, political and military pressure on Iran. The introduction of such policies toward Iran by the Trump administration has not only been brought about by Trump himself, but also influenced by the domestic political environment of the United States. Moreover, it is also closely related to the current changes in the geopolitical landscape of the Middle East. The Iran policy of the Trump administration will likely have multiple impacts, such as giving rise to political instability within Iran, worsening regional security,impacting the international non-proliferation regime, widening the disparity between the US and Europe, and even increasing the possibility of a military conflict breaking out between the US and Iran. Full text available here.