Former Al Ahram editor Heikal, author of The Sphinx and the Commissar (among others), is presently in jail in Cairo--thanks to his old friend, the late President Sadat. A moderate Arab nationalist is hard put in today's Middle East. From that vantage point, Heikal recounts the struggle between shah and ayatollah as well as it's been told: sympathetically yet critically, comprehensively (from 1953 onward) yet concisely. And he's come up with a bit of a revelation: namely, that soon after the Shah's fall the new revolutionary authorities found out who the SAVAK man in the US embassy was and used him to get information. Code-named Hafiz (Heikal doesn't disclose his true identity except to say that he was neither American nor Iranian), this operative agreed, under promise of immunity, to keep on spying for his new bosses. What he produced was documents outlining various plans for getting the Shah into the US--including one, penned by State Department Iranian expert Henry Precht, which foresaw the possibility of Americans being taken hostage if the Shah were admitted before embassy security could be beefed up. This document became well known after the embassy seizure when it was made public as justification for the takeover; but Heikal now reveals that the Iranians had it in their possession all along--the seizure was a reaction, as he explains it, to the knowledge that such plans were in the works. After obtaining the information, Hafiz was flown out of Iran to Paris, where he ""disappeared."" To Heikal, CIA ignorance of the two-month-old plans to attack the embassy is evidence of how cut off from the Iranian reality the Americans had become. He also relates efforts to get him to act as an intermediary in negotiations for the hostages' release--which, he thought, would be in the Iranians' best interest--and, in the process, shows how confused American signals were (a sentiment often expressed in reverse by American officials). It was only when Algerians were brought in as the single intermediary that progress was made. For the future, Heikal avows no faith in the restoration of Bani Sadr, and expects the army to emerge eventually as the power center. A lively and knowledgeable reprise--with that potential news-item as a hook.