The British blockade probably did more for the downfall of Mossadegh than the US influence on the Shah. Iran's economy was severely impacted by the blockade and this allowed the Shah to gain support within the Iranian government for a coup. The US decided to support a coup because it was feared that a collapse of the Iranian economy would open the door to communist revolutionaries, and the US was not prepared to go against Britain and try to stop the blockade. I have wondered, however, if the outcome of the Iran situation in 1953 affected Eisenhower's judgment about the Suez crisis in 1956.

By 1979 it was no longer possible to marshal public anger towards the UK whose empire had been completely dismantled. Meanwhile, the US continued to support the Shah's regime by selling weapons until 1979, and this was probably at least as important as the coup for the image of America as a public villain during the Islamic Revolution.