Twice in Iran a political figure has emerged after the 1979 Islamic Revolution to spark hope among the international community.

The first was reformist president Mohammad Khatami, elected in 1997. Khatami was the man with the perpetual smile, who, despite concerted efforts during eight years in office, was unable to establish better relations with the West or dramatically change Iranian society.

The second is Hassan Rouhani, the newly elected president of Iran, who will be coming to New York this week for the annual United Nations confab. Like Khatami, Rouhani wears a constant smile on his face and speaks in measured tones. But who is this man who earlier this year succeeded Mahmoud Ahmadinejad, a president known neither for his smile nor his measured tones?

A religious scholar by training, Rouhani opposed the rule of the shah, and, as a young man, was a keen follower of Ayatollah Khomeini. Rouhani started his religious studies in 1960 at Semnan Seminary, got his B.A. in judicial law in 1972 from Tehran University, and, six years later at age 30, moved to London to study English. At the time, social unrest was sweeping his country, and a year later, the shah was overthrown. According to his memoir, Rouhani intended to study at Harvard University, but because of the turbulent situation at home he instead went back to Iran. During the 1990s, however, he went abroad again to finish his postgraduate studies at Glasgow Caledonian University. His Ph.D. thesis was titled “The Flexibility of Shariah (Islamic Law) with reference to the Iranian experience.”

“He was very serious and tenacious in his work,” says Abolfazl Mehrabadi, the deputy director of the Islamic Republic of Iran Interest Section in Washington, who first met Rouhani in the 1980s. Unlike many Iranian clerics and officials who consider the West a place of corruption, Rouhani took a different view. “He knew the West well and was quite familiar with the principles of democracy, and respected it with his deep knowledge of it,” says Mehrabadi. “This is why he was talking about these principles … during this year’s election debates.”

To those hoping for domestic reform in Iran, there have already been encouraging developments. Last week, the president gave a speech in which he obliquely warned the powerful Revolutionary Guards Corps to stay out of politics, though he was careful not to alienate the elite, conservative force. Observers believe that Rouhani wants to curtail the political influence of the Revolutionary Guards Corps, which, through its paramilitary troops, has been instrumental in tamping down on protesters demanding more rights.

Tehran’s former mayor, Gholamhossein Karbaschi, who met with Rouhani both before and after the June election, told The Daily Beast that Rouhani throughout his political life “has tried to control extremism and radicalism among the Iranian political forces.” The three words to best define Rouhani are “disciplined, rational, and convincing,” according to the former mayor, who says that Rouhani is meticulous in both form and manner. “He pays serious attention to his clothes and appearance,” says Karbaschi, adding that the president is known for his verbal skills. “Sometimes he defeats his opponent through jokes and humor. He is an intelligent and expert orator, never interrupts anyone, and pays close attention.”

His interest in policy and analysis led him to one of Iran’s most well-known think tanks—the Center for Strategic and International Studies and Research—which was founded by the Expediency Council, an advisory body with legislative power.

Massoud Safiri, who worked at the center until 2007, often interacting with Rouhani, told The Daily Beast that Rouhani is unfailingly polite, and, unlike many other clerics, refrains from using profanities or sexual slurs during meetings. Safiri recalled one meeting, headed by Rouhani, concerning television programming. During the meeting, Rouhani was thoughtful and pithy, and in his reasoning—again unlike other clerics—didn’t refer to religious sources but to statistics and scientific research. “In that meeting he said that if the majority agrees with the decision, ‘I agree, too.’” Safiri believes that Rouhani has no illusions when he talks about reducing tensions with the West but knows exactly what steps to take. “You can be sure that he has a plan for it, too, and with the support he has from the Supreme Leader [Ali Khamenei], he can get it done,” says Safiri.

“From a political viewpoint, he is regarded a moderate right, which means he believes in liberal economic policies and if, for example, he has to make a choice between the U.S. and China ... he would choose the U.S.,” says Hooshang Amirahmadi, a professor at Rutgers University and president of the American Iranian Council. Rouhani’s election, Amirahmadi says, suggest that change may be afoot. “I believe that the Islamic Revolution is getting tired of itself and the old revolutionary games are no longer popular in Iran.” Yet, these are early days, and the president’s ultimate aims are unclear, says Amirahmadi. “Mr. Rouhani has always moved in the shadows.”

For all his outwardly geniality and courtesy, there is more to Rouhani that meets the eye, says Jahanbakhsh Khanjani, a former Interior Ministry official. Rouhani has “hidden layers,” he said, obliquely suggesting that it might be harder than we think to predict the new president’s priorities and plans.