Iran–United States relations

Relations between Iran and the United States began in the mid-19th century, when Iran was known to the Western world as Qajar Persia. While Persia was the object of British and Russian colonial interests during the Great Game, the US gained the trust of its leaders, with Arthur Millspaugh and Morgan Shuster appointed treasurers-general by the Shahs. During World War II, Iran was invaded by the United Kingdom and the Soviet Union, both U.S. allies. Relations remained positive until the Mohammad Mosaddegh government was overthrown by the 1953 Iranian coup d'état, organized by the Central Intelligence Agency, and assisted by MI6. This was followed by an alliance between Shah Mohammad Reza Pahlavi's regime and the US government. From being close allies during the Cold War, Iran-US relations flipped after the 1979 Iranian Revolution, when Ayatollah Ruhollah Khomeini took power.

The two nations have had no formal diplomatic relations since 1980: Pakistan and Switzerland serving as protecting powers for Iran and the US respectively. Communication goes through the Pakistani Embassy in Washington and the Swiss Embassy in Tehran. Since 1995, the United States has had an embargo on trade with Iran. Relations improved when the two countries had overlapping goals, such as joining forces in the war against the Islamic State.