What has Iran done to make the United States "kill"?

Although Iran has a small land area, it is one of the major economies in Asia, which shows that its economic strength is still very strong, but its relationship with the United States is not good recently. Have they always been on bad terms? Actually, it's not like this.

Once, they were also a pair of allies. Just as the United States unconditionally supports Chiang Kai-shek, it also supports Iran very much. Even during the Pahlavi dynasty, the F 14 fighter plane just developed by the United States was sold to Iran, and only Iran obtained the export right of the F 14 fighter plane. The United States is unprepared for Iran, and all kinds of advanced weapons will be sold to Iran. Now the main force of Iran is mostly Iran.

If they were so good before, why did the United States kill Iran? The main reason is 1979 Iranian Islamic Revolution, which overthrew the Pahlavi dynasty that the United States has always supported, established a new regime and opened an anti-American storm. Because the United States also supported Israel, they also began to be anti-Jews. Of course, the United States cannot suffer such losses. It encourages Iraq to wage war against Iran. This battle was fought one after another.

Iraq was once a great power in the Middle East. Iran won this battle, and Iran has a deep hatred with the United States. The United States also wants to control the Middle East and intervene everywhere. This has led to the struggle for regional dominance, which has made Iran and the United States even more incompatible, resulting in a situation of either death or injury. Both sides are tough and hatred has accumulated for a long time.