What was the effect of Carter's attempts to free the hostages in Iran? The hostages were returned to the United States immediately. The United States increased its purchase of Iranian oil. All of Carter's attempts failed. The Sandinistas were overthrown.

Carter's attempts to free the hostages in Iran ultimately ended in failure, most notably highlighted by the ill-fated rescue mission known as Operation Eagle Claw in April 1980. This mission aimed to rescue 52 American diplomats and citizens taken hostage by Iranian militants, but it resulted in a tragic crash that claimed the lives of eight U.S. servicemen and led to a further sense of humiliation for the Carter administration. In the political landscape, these failed attempts tarnished Carter's presidency, contributing to his loss in the 1980 election to Ronald Reagan. The hostages were eventually released on January 20, 1981, coinciding with Reagan's inauguration, leading many to speculate that Iran intentionally delayed their release to diminish Carter's political standing.