It was late in 1973 when Akbar Etemad got the call -- the shah wanted to discuss ways to launch a nuclear program that would cement Iran's place among the world's modern nations.
Mohammad Reza Shah Pahlavi had reached the conclusion that Iran needed to diversify its energy sources for the future in order to provide for a rising population.
The Swiss-educated Etemad, an expert on atomic energy and chancellor of Bu-Ali Sina University in Hamedan, set to work on preparing a feasibility study for the construction of several nuclear power plants.
A month later he personally delivered his findings to the shah, who immediately started reading the study.
"The shah read the report in about an hour and a half, while asking questions," Etemad told RFE/RL by telephone from France. "When he was done he handed the report to [Prime Minister Amir-Abbas] Hoveyda and said: 'I fully agree with Etemad's [assessment]. This has to be carefully implemented.'"
So it was decided. Iran was going nuclear, and Etemad would be the man to steer the program.
The first step -- getting the shah up to speed so he could make informed decisions. Every week, for half a year, Etemad personally gave the shah lectures on nuclear energy and nuclear technology.
Over the course of those discussions, Etemad says, he tried to get a feel for the shah's thinking. Did he seek a nuclear program entirely for peaceful purposes, or one that would also include a military dimension?
"It wasn't easy to understand his aim," he says.
After about six months of tutoring, Etemad cautiously broached the subject.
"One day I told the shah: 'Now that you know the difference between building a reactor and a bomb, enrichment, and so on, what do you want me to do?'"
Etemad says the shah told him that the priority was to gain access to nuclear energy, but he appeared to leave his options open for the future development of a nuclear weapon.
"Right now we don't need a nuclear weapon because Iran is a major regional power," Etemad recalls the shah saying. But if in the next 10, 15, or 20 years the regional military balance changed, the shah added, "then we would have to see what needs to be done."
As a result, Etemad worked to ensure that if Iran ever decided to build a bomb, it would be able to do so.
Looking to gain the capability to realize its ambitious plans for a civilian nuclear program -- the construction of 23 nuclear reactors, giving it the capability of generating 23,000 megawatts of power -- Iran began negotiating with a number of Western countries.
In 1974, Tehran signed on to the Nuclear Nonproliferation Treaty's Safeguards Agreement, allowing inspections and allaying concerns that nuclear enrichment could be used in the development of nuclear weapons.
The same year, it reached an agreement with the German company Kraftwerk Union to build two nuclear reactors in Bushehr, and negotiations were begun with France on the construction of two additional reactors.
Iran also began discussions with a powerful ally -- the United States, which expressed support for the shah's nuclear ambitions but had reservations about his desire to process nuclear fuel.
The negotiations that took place with Washington from 1974 until 1978, Etemad reveals, faced obstacles from the start and led him to conclude that no deal could be worked out.
"In my head, I had erased two countries," Etemad recalls. "One was America, the other the Soviet Union."
The reason, he explains, was because while the two powerful states would negotiate, they would do so in an effort to impose their own views.
"I didn't want to play by their rules," Etemad says.
In the end Washington and Tehran did manage to initial a deal, in 1978, under which Iran would be allowed to reprocess U.S.-supplied nuclear fuel in exchange for agreeing to safeguards.
But it was never to be. The 1979 Islamic Revolution put an end to the shah's rule, his nuclear dream, and nuclear cooperation with the United States.
Etemad wasn't around to see his plans unravel -- he left the country shorty before the revolution. But he watched closely as the Islamic Republic ground the nuclear program to a halt, made tepid attempts in the 1980s to restart nuclear research, and then decided in the 1990s to pursue the path the shah had taken.
He has also watched the resulting controversy over the Islamic Republic's sensitive nuclear activities, which have raised fears that Tehran was pursuing a nuclear weapon and have resulted in economic sanctions and international isolation.
As Iran and major powers attempt to conclude a deal that can both assuage Western fears and provide sanctions relief for Tehran, Etemad is optimistic that something will be worked out.
But he also says it will only be a "good agreement" for the Western states. "They will impose [their demands] on Iran," he says. "That's the end of the story."
Asked whether Tehran's nuclear program was worth the pressure the country has faced, Etemad replies with a simple "No."
"The goal of the nuclear program is not clear," he says. "I don't know what the goal has been since the revolution."