https://1997-2001.state.gov/statements/2000/000317.html
In 1953 the United States played a significant role in orchestrating the overthrow of Iran's popular Prime Minister, Mohammed Massadegh. The Eisenhower Administration believed its actions were justified for strategic reasons; but the coup was clearly a setback for Iran's political development. And it is easy to see now why many Iranians continue to resent this intervention by America in their internal affairs.
Moreover, during the next quarter century, the United States and the West gave sustained backing to the Shah's regime. Although it did much to develop the country economically, the Shah's government also brutally repressed political dissent.
As President Clinton has said, the United States must bear its fair share of responsibility for the problems that have arisen in U.S.-Iranian relations. Even in more recent years, aspects of U.S. policy towards Iraq, during its conflict with Iran appear now to have been regrettably shortsighted, especially in light our subsequent experiences with Saddam Hussein.