THERE IS a voyeuristic fascination in how the mighty fall. The titles of these two books, so nearly the same, pander to this taste. Yet in neither case is the author strictly concerned with "the fall of the shah."

Amin Saikal, a political scientist of Afghan origin, focuses essentially on the shah's foreign policy and the relationship of the Great Powers with Iran. The shah's demise is woven into this. Fereydoun Hoveyda was Iranian ambassador at the United Nations and is the brother of Amir Abbas Hoveyda -- the shah's longest-serving prime minister, who was executed by the Khomeini regime. He is mainly out to avenge the memory of his brother, "the innocent victim of the excesses of a dictator [the shah]."

The Saikal book is a serious academic study. He says as much in that dreadful jargon so popular with academics: "an in-depth, macro-level analysis of the shah's rule with respect to the linkage that existed between his domestic and foreign policy postures, as well as between these and the relevant evolving changes in regional and international politics." His study is ultimately flawed by its lack of originality, whether in term of judgements or material.

The Hoveyda book has been rushed into print as an insider's view of the shah's regime. It is personalized, gossipy, peppered with the occasional sharp insight or anecdote; but Fereydoun Hoveyda was rarely a direct participant in the drama and he contributes little more than could be gleaned from the Iranian and international press.

Both books, therefore, make a deceptive promise. Saikal pledges to investigate in depth that vital relationship between Iran and the United States. Yet he merely treads well-worn ground on the key issues -- the CIA overthrow of Mossadeq, the setting up of the hated SAVAK, Kennedy's arm-twisting of the shah to appoint his opponent, Ali Amini, as premier, and the Nixon-Kissinger endorsement of the shah as the anti-communist policeman of the Gulf. Fereydoun Hoveyda tells tantalizingly little about his brother, who was prime minister from 1965-77 and was court minister until resigning in September 1978. He deserves a serious study, and this apologia can do his record little good.

The main value of Saikal's book lies in his careful description of Soviet-Iranian relations. The background he offers here has particular relevance to the Soviet invasion of Afghanistan -- as indeed does the shah's foreign policy towards that country. His chapter on oil policy is also a useful reminder that, while virtually everything the shah sought to do for Iran has either crumbled or been rejected, his oil diplomacy remains a lasting legacy. The shah's hawkish stand on oil prices provided OPEC with the necessary muscle in the early '70s to obtain realistic value for this "noble product."

Both authors coincide on the generally held view that it was failure to utilize oil wealth, through lavish over-spending and wholesale resort to foreign skills, which helped provoke his downfall. Saikal also stresses the inherent weakness of capitalist-based development in a fragile political system that depends upon one man. Fereydoun Hoveyda goes deeper into the shah's psyche, seeing stubborness, vindictiveness and hubris. He accurately pinpoints the shah's pandering to his own family, especially his twin sister, Princess Ashraf, which meant that corruption thrived.

Fereydoun Hoveyda recounts a conversation with his brother about corruption. "I then asked the inevitable question: 'Why don't you take them to court?' He gave me a despondent look. 'I don't take them to court? I do nothing else but take them to court! But what's the use? The campaign has to begin at the top, with the shah's family and entourage. Otherwise it's pointless. And anyway it isn't fair to hit the minnows when the big fish are getting away.'"

The author depicts his brother as someone desperately trying to do the right thing in a rotten system. He quotes a conversation on the prime minister's responsibility for what is happening: "He [the shah] makes the decisions himself. I don't even know what is happening in the army and SAVAK . . . I try to do my best. I have never stolen a penny." Hoveyda claims that the shah imprisoned his brother on the promptings of the then ambassador to the United States, Ardeshir Zahedi.

The arrest of Amir Abbas Hoveyda was a cynical act of self-preservation by the shah; but the book ignores any suggestion of guilt. He did not control SAVAK -- true; but he was in office as premier in the worst period of repression. The fateful decision to double planned spending in 1974 was fully endorsed by him in public and he was a full party to the formulation of that decision. I suspect that his brave refusal to escape during the confusion of the revolution (he telephoned Khomeini's headquarters to signal his whereabouts) was in part to expiate a certain guilt, knowing also he had nothing to lose by martyrdom. He was executed as a surrogate for the shah.

This brings me to something neither author chooses to confront. Surely a key question when reflecting on the demise of a dictatorship is why it lasted so long. By now the reasons for the shah's downfall have become pretty obvious. But this question has been obscured because it is often uncomfortable and less easy to answer. If the system was so rotten after 1975, as Hoveyda says both he and his brother knew, why serve the shah? Loyalty was one explanation -- through a deep-seated acceptance of the monarch as father-figure and symbol of Iranian unity. Amir Abbas is quoted as saying: "In this country you can't resign. You have to not get involved in the first place." Working for the shah compromised you. But many educated Iranians, like Fereydoun Hoveyda, were prepared to accept such a compromise, believing in the shah's modernizing aims and bought off with the material gains of oil-wealth. Thus when things started to go wrong a common reaction was to feel that the shah had let them down.

There was among the ruling class a tremendous and permanent mutual mistrust which the shah cleverly exploited. And when this tactic failed there remained the ultimate sanction: repression. SAVAK was brutally pervasive; people were cowed into collaborating with the regime. Unwittingly Fereydoun Hoveyda provides a typical example of this type of cowed obedience. When the shah created a single-party system in 1975, all officials were invited to join. Hoveyda watched over glum faces at his U.N. office while Iranian officials signed on for party membership. Afterwards, he says, they expressed their displeasure in private. The party was a sham from the start -- they new it; but no one threw the membership book out of the window. By accepting the system in public which in private they hated, such people abdicated the chance of influencing the revolution.