Final answer:
The mutual admiration between the US and Iran deteriorated due to the US-backed 1953 coup in Iran, support for the Shah's oppressive regime, and the 1979 Iranian Revolution which introduced an anti-Western government. The 1979 hostage crisis epitomized the breakdown in relations as Iran demanded the return of the deposed Shah and an apology from the US.
Step-by-step explanation:
Breakdown of US-Iran Relations
The breakdown in the mutual admiration between the United States and Iran can be traced back to a series of political and social upheavals. Originally allies, with the US extensively supporting the Shah's regime with military aid and economic assistance, the relationship began to sour as the Shah's modernization policies and political repressions incited dissatisfaction among various Iranian factions. Moreover, the United States' direct involvement in the 1953 coup that ousted Prime Minister Mohammad Mossadegh and the subsequent support for the Shah's authoritarian rule, contributed to a growing resentment among the Iranian populace.
A seismic shift occurred in 1979 with the Iranian Revolution, replacing the pro-Western Shah with the anti-Western Ayatollah Khomeini. The revolution was fueled by frustration over the Shah's excesses, political repression, and the perceived exploitation by the US, particularly in relation to Iran's oil resources. The hostage crisis of 1979, where American embassy staff were held captive for 444 days, symbolized the definitive collapse of friendly relations as Iran demanded the return of the Shah to face trial and for the US to apologize for its role in the 1953 coup.