Just as Hassan Rouhani's second four-year term was set to start, US officials announced new sanctions against Iran - a clear violation, officials in Tehran said, of the international nuclear deal signed, sealed and delivered in 2015, back when the United States had very different leadership. Nevertheless, Rouhani, who was re-elected by a landslide in May, has vowed to keep up his efforts to end Iran's economic and diplomatic isolation from its potential international partners.

"We will never accept isolation," Rouhani said on Thursday after receiving the formal endorsement of Supreme Leader Ayatollah Ali Khamenei. "The nuclear deal is a sign of Iran's goodwill on the international stage."

Rouhani, a relative moderate re-elected for his efforts to repair relations with the US and EU and enact incremental changes at home, is no stranger to big challenges. And - with a belligerent counterpart in the United States, ongoing proxy wars in several Middle Eastern countries and strong opposition to his efforts from Iran's various ruling factions - he will have no reprieve from them in his second term.  

'Hear everyone's voices'

Events that began when British intelligence services and the US's Central Intelligence Agency collaborated to overthrow Iran's democratically elected communist-leaning government in 1953 would set Rouhani up to play an important role in two of the Middle East's most important modern-era moments - first from 1978 to 1979 and again from 2013 to now.

Born in 1948 to religious parents in the small town of Sorkheh, Semnan province, and schooled in seminaries in the 1960s, Rouhani completed a law degree at the University of Tehran in 1972 and began compulsory military service under the shah in 1973. However, Rouhani's opposition to the government of Mohammed Reza Shah Pahlavi had already begun when he was a teenage Islamist in the 1960s, with the young cleric traveling the country to denounce Iran's US-backed leadership.

Rouhani's opposition to the government and support for the exiled Ayatollah Ruhollah Khomeini would see him arrested several times and ultimately banned from speaking in public. Nevertheless, he persisted, continuing to denounce the shah and express his support for Khomeini, before eventually joining the ayatollah in exile in 1977 and delivering speeches to Iranians abroad in an effort to rally support for what would become the 1978-79 revolution. Though he was a loyalist to Khomeini and a reliable functionary for decades, in the theocratic government that emerged from the revolution, his relatively moderate views would allow him to run for president as a reformer by 2013 - and begin the slow thaw with the United States that resulted in the 2015 nuclear deal.

"Even in my previous political career, previous to the presidency, I made good use of both sides," Rouhani told the US news organization NPR in 2015, shortly after his administration reached the nuclear deal. "So, what is of utmost importance for me is to say that conservatives and those who move ahead, those who are not extremists, can do much better for their country," he said. "Those who have their own opinions or differing opinions as far as social issues or cultural issues are concerned, we need to hear everyone's voices when it comes to that. And the nation can always only benefit from those who are not extremists, and those who wish to move down the middle of the road and encompass both views and all views."

From both sides

With Mahmoud Ahmadinejad termed out after eight years in 2013, Rouhani ran as something of a compassionate conservative against five authorized opponents - all of them, like him, insiders of one sort or another. He handily beat his nearest competitor, populist Tehran Mayor Mohammad Bagher Ghalibaf, by a margin of 34 points, to emerge as the elected president with 50.71 percent of the vote on a turnout of nearly 73 percent. Though he faced opposition from Iran's hard-liners from the moment he announced his candidacy, which would only increase when he took the office, Rouhani had a mandate to press the reforms he had pledged. He disappointed supporters early, however, when he appointed an all-male Cabinet, despite having paid lip service to acknowledging women's leadership abilities in his campaign.

On September 27, 2013, Barack Obama called Rouhani, and the presidents held the first conversation between US and Iranian leaders in three and half decades. At the end of the call, Rouhani wrote on Twitter at the time, he told Obama to "have a nice day," to which the US president responded: "Thank you. Khodahafez" - the Farsi word for goodbye. But that was just the beginning, and after two years of tough negotiations, and plenty of opposition from conservatives in Iran and the United States, Rouhani's government reached a deal with the five permanent members of the UN Security Council and the EU to neuter his nation's nuclear program in exchange for sanctions relief.

Rouhani, who has expressed interest in tackling Iran's economic woes during his second term, has yet to receive a call from Obama's replacement, Donald Trump, but that doesn't mean that there haven't been clear messages from Washington:

Trump vocally shares Iranian hard-liners' skepticism that the nuclear agreement achieved at the top level by diplomats in Beijing, Moscow, Brussels, London, Paris, Washington and Tehran will hold. This puts Rouhani somewhere in the middle of an old bullheaded battle between steadfast factions. It's an uncomfortable position, to be sure, but so far that's where he's done his best work. 

mkg/cl (Reuters, AFP, AP)