Eisenhower took a dimmer view of reform movements than his predecessor and gave the go-ahead to the 1953 coup that removed an increasingly erratic and authoritarian Mossadegh and restored the Shah. This ushered in a ‘you break it, you own it’ phase from 1953 to 1960, characterised by the consolidation of the Shah’s rule and the establishment of what Mark Gasiorowski has termed the cliency relationship. The coup may have been long anticipated but this did nothing to lessen its impact. The shoring up of an authoritarian monarch at democracy’s expense put an indelible stain on US–Iranian relations that has retained a vibrant immediacy undiminished by time, and forms another thread in the narrative.
The intelligence analysis surrounding the event confirmed its success while, at the same time, warning that the intervention had done nothing to mitigate future problems. ‘The overthrow of the Mossadegh government on 19 August 1953 checked the drift in Iran toward Communism and isolation from the West’, confirmed the 1953 National Intelligence Estimate (NIE) on probable developments in Iran through 1954. It added, however, that ‘the accession of Zahedi to power [the Shah’s new Prime Minister] had eliminated neither the economic and social problems which have long plagued Iran, nor the weaknesses and inadequacies of the Iranian political system’. Now tied to the Shah as never before, the Eisenhower administration increased its support (both development aid and military assistance), training, for example, the Shah’s secret police, the Organisation for State Security and Information (SAVAK). The Shah’s consolidation of power and his insistence that the US facilitate his desire for a large national-security capacity (as opposed to help with and pressure regarding socioeconomic reforms) made it an uneasy association. In late 1954 analysts noted:
"So long as the Iranian government continues to expect US economic, financial, and military assistance, it will remain responsive to US influence. As oil revenues are restored and US aid is reduced, however, Iranians may become increasingly determined to manage their own affairs and more resistant to US guidance."
Two years later, the assessment had acquired a more guarded tone: So long as the Shah retains control, Iran will almost certainly seek to identify its interests with the US. However, the continuation of such a course depends heavily on US support for Iran and the maintenance of US prestige in the Middle East.
The analysis hit upon a dilemma that few at the time grasped with clarity: the US could ensure a supportive monarch only by providing significant assistance, which it tried to do while keeping Iran at arm’s length. This assistance, however, was increasingly perceived by opponents of the regime as proof that the US was pulling the Shah’s strings. It was an imperfect reading of the complex relationship but one that would gather force. By the end of the decade, the debate in Washington about the Shah’s future was overtaken by a series of coups in the region. At a time, this may not have caused much, if any, consternation in the White House. Indeed, the possibility of a US-backed coup was not entirely without foundation. The Shah, after all, had proved an unwilling reformer and, analysts thought, had perhaps fatally undermined his position as a result. Amidst the upheavals, however, and with rumours of coup attempts abounding, Eisenhower decided to shore up his one known quantity. With the signing of a bilateral defence agreement in March 1959, a new phase had begun.