( CNN ) -- The less-than-confrontational comments coming from new Iranian President Hassan Rouhani are not what the West is used to hearing from that country 's office in recent years . Rouhani , a cleric and moderate politician elected in June , has signaled his desire for better engagement with the West , most recently in a Thursday Washington Post op-ed , in which he called for an end to `` the unhealthy rivalries and interferences that fuel violence and drive us apart . '' Coming a week before he 's to attend the U.N. General Assembly in New York , Rouhani 's op-ed called for nations to work together on contentious issues such as Iran 's nuclear program . And he offered to broker efforts to bring peace to Syria , a long-time Iranian ally torn by civil war . Given Iran 's closeness to Syria 's government , it seems unlikely rebels would consider Rouhani an independent broker . But Rouhani 's tone is far less fiery than that of his predecessor , Mahmoud Ahmadinejad . And Rouhani 's promise of more positive engagement with the world during his election campaign appeared to propel him to victory . Rouhani , 65 , enjoyed reformist backing and took more than 50 % of the vote . Three of the six candidates were much more conservative , and the Iranian public viewed Rouhani as a mild alternative . But how just how conciliatory is Rouhani ? Hassan Rouhani is Iran 's next president . Hawk or dove ? Rouhani has a reputation for avoiding extreme positions and bridging differences , but he is no pushover . He has a long history of service in the country 's defense establishment . He is a former commander of the Iranian air defenses , is a leader on three war and defense councils , and was national security adviser to the president for 13 years before Ahmadinejad took office . Rouhani is also a diplomatic and legal intellectual . He has three law degrees , including a doctorate from a university in Scotland , and as president of Iran 's strategic research center , he regularly publishes essays . He has served as managing editor for three quarterlies on scientific and strategic research , and foreign policy . He was also Iran 's chief nuclear negotiator from 2003 to 2005 during the presidency of Mohammad Khatami , who later became one of the leading figures in Iran 's rebellious `` Green Movement , '' which erupted into street protests after the re-election of Ahmadinejad in 2009 . Ahmadinejad 's government violently quashed the protests with the help of elements of a unit of the Revolutionary Guard , which answers to Ayatollah Ali Khamenei , Iran 's supreme leader . Rouhani has expressed support for the Green Movement . `` These were protests that were natural and popular , '' he has said . `` They should have been addressed . '' After Green supporters chanted for him at a rally , security forces arrested members of his campaign . Relationship with Khamenei . Rouhani 's relationship with Khamenei has the potential to be complex . He represented the supreme leader on Iran 's security council for many years . But Rouhani has purportedly also suggested Khamenei is too rigid toward the international community , said Abbas Milani , who runs a research program on Iran at Stanford University . In a book about his experience as Iran 's nuclear negotiator during Khatami 's presidency , Rouhani criticizes Ayatollah Khamenei , according to Milani . `` If you read in between the lines , he places a lot of blame on Khamenei , '' Milani says . `` He says in his book that if it was up to him , he and his team would have come up with a solution that would not lead up to Iran 's case being deferred to the U.N. -- saying 'we could have done this , and some people in Iran and some in the West torpedoed it . '' A televised presidential debate turned into an animated political clash and touched on Iran 's nuclear program . Exchanges grew so heated that the candidates were later accused of having revealed national secrets during the debate . Rouhani was warned that he could be barred from running in the elections because of confidential material he revealed about Iran 's nuclear program during the two-hour-long debate . It was n't his first testy moment with Iran 's state-run media . He has openly accused it of censorship and publishing lies . Many believe Rouhani was not Khamenei 's favorite candidate . But Khamenei has said he is not playing favorites and would not let on whom he voted for . And Khamenei and his Guardian Council had to approve all candidates before the race began . Out of 680 who applied to run , only eight were allowed to do so . Two later dropped out . Ultimately , the supreme leader approved Rouhani 's candidacy after rejecting the candidacy of a former president , Akbar Hashemi Rafsanjani . Rafsanjani endorsed Rouhani during his campaign . Rouhani is a senior cleric and still is a member of the Assembly of Experts , which is responsible for appointing or removing the supreme leader . As Khamenei ages and the appointment of a successor becomes necessary , Rouhani will likely have influence on the choice . CNN 's Reza Sayah , Azadeh Ansari , Tara Kangarlou , Mitra Mobasherat , Laura Smith-Spark and Greg Botelho contributed to this report .
Hassan Rouhani holds a doctorate from a university in Scotland . He had a long career in Iran 's defense establishment . A senior cleric , he was Iran 's chief nuclear negotiator and writes on diplomacy . He has made comments in support of Iran 's rebellious Green Movement .