So complicated, in fact, he ducked an opportunity to lunch with U.S. President Barack Obama and other world leaders at the U.N. General Assembly last week and was unable to agree to a face-to-face with Obama while the two were in New York.
"It's too complicated," a senior administration official told reporters in announcing there would be no meeting of the two presidents.
"We indicated that the two leaders could have had a discussion on the margins if the opportunity presented itself. The Iranians got back to us; it was clear that it was too complicated for them to do that at this time given their own dynamic back home," the official said.
And there's the crux of the issue: Rouhani may be making all the right noises about opening Iran's nuclear program to international inspection and denying weapons ambitions, but when it comes to concrete actions, it's complicated.
In a CBS interview Wednesday, Rouhani gave the matter a slightly different spin, saying after 35 years of no relations between Iran and the United States, a meeting between him and Obama would need careful preparation.
"We must make every effort so that the first high official meeting will definitely yield positive results," Rouhani said.
Late Friday, Obama said he had talked with Rouhani by phone and was hopeful an agreement can be reached.
"We're mindful of all the challenges ahead," Obama said. "The very fact that this was the first communication between an American and Iranian President since 1979 underscores the deep mistrust between our countries, but it also indicates the prospect of moving beyond that difficult history.
"I do believe that there is a basis for a resolution. Iran's supreme leader has issued a fatwa against the development of nuclear weapons. President Rouhani has indicated that Iran will never develop nuclear weapons.
"I have made clear that we respect the right of the Iranian people to access peaceful nuclear energy in the context of Iran meeting its obligations. ...
"Resolving this issue, obviously, could also serve as a major step forward in a new relationship between the United States and the Islamic Republic of Iran -- one based on mutual interests and mutual respect. It would also help facilitate a better relationship between Iran and the international community, as well as others in the region."
A senior administration official later said the call was set up when the administration became aware Rouhani wanted to speak with Obama before heading back to Tehran.
"I think what we would say is we're trying to achieve an objective that we believe could serve the interests of the United States, Israel and the world, which is a resolution that involves Iran coming in line with its obligations, not developing a nuclear weapon," the official said. "And again, I think that that would advance our security; it would also advance Israel's security if we can achieve a meaningful, transparent, verifiable agreement."
The West and Iran's neighbors are hopeful the winds of change are blowing through ancient Persia with Rouhani's election given the intransigence of predecessor Mahmoud Ahmadinejad. And indeed Rouhani spent much of the run-up to this week's U.N. General Assembly giving interviews to western media, saying the words the peacemongers long to hear. He even acknowledged the evil of the Holocaust -- but at the same time said the wrongs inflicted by the Nazis doesn't give another country, an obvious allusion to Israel, the right to occupy another people's lands, meaning the West Bank.
In his U.N. speech, Rouhani spoke of hope: "the hope of universal acceptance by the people and the elite all across the globe of 'yes to peace and no to war'; and the hope of preference of dialogue over conflict, and moderation over extremism."
At the same time, he took a swipe at the West, denouncing as folly attempts to make Western values a universal, calling such efforts the actions of a nation with a superiority complex destined to fan "fear and phobia." He also denigrated fears Iran seeks to become a nuclear power as an "imaginary" threat.
"Let me say this in all sincerity before this august world assembly, that based on irrefutable evidence, those who harp on the so-called threat of Iran are either a threat against international peace and security themselves or promote such a threat. Iran poses absolutely no threat to the world or the region. In fact, in ideals as well as in actual practice, my country has been a harbinger of just peace and comprehensive security," Rouhani said.
Western intelligence agencies have said Iran long has been fomenting strife in the Middle East, arming Hezbollah, Hamas and numerous other militant groups bent on the destruction of Israel. It backs the Assad regime in Syria and Hezbollah efforts to control Lebanon, and has called a state sponsor of terror.
This is a harbinger of "just peace?"
Israeli Prime Minister Binyamin Netanyahu, who addresses the United Nations this week, labeled Rouhani's speech "cynical."
"It is no coincidence that the speech lacked both any practical proposal to stop Iran's military nuclear program and any commitment to fulfill U.N. Security Council decisions," he said.
Rouhani indicated his main goal is to get the West to lift sanctions that have crippled Iran's economy to deprive it of the funds it needs to finance its nuclear program.
Netanyahu said Rouhani is just playing for time -- keep the West talking while its scientists keep working and the centrifuges keep spinning until it's too late to prevent a nuclear Iran.
Israel is believed to have played a pivotal role in producing setbacks to Iran's nuclear development. Iran has blamed the Jewish state for unleashing the Stuxnet virus, which played havoc with Iran's centrifuges, and assassinating a number of its nuclear scientists. Israel also has repeatedly threatened to use military force to prevent Iran from gaining nuclear capability.
Washington wants a diplomatic solution. Secretary of State John Kerry and his counterparts in the so-called P5-plus-1 (the five permanent members of the U.N. Security Council plus Germany) met with Iranian Foreign Minister Mohammad Javad Zarif Thursday to kick off what White House spokesman Jay Carney said Obama is hoping will be substantive negotiations. Kerry and Zarif also had a one-on-one meeting.
"The window, as we've been saying for some time now, even predating the elections in Iran, is open to resolve this diplomatically, but it is not -- it will not be open indefinitely," Carney told a news briefing last week.
"The president was open to an informal encounter, but even if something like that had happened, that is less significant than whether or not the Iranians demonstrate seriousness of purpose when it comes to making progress in negotiations that have been available to them now for many years. And their failure to be serious about it for so many years has led to the most comprehensive and punishing sanctions regime in history. ...
"It is our policy that Iran cannot be allowed to develop a nuclear weapon. And it is the international community's position embodied in the various resolutions of the United Nations Security Council and elsewhere that Iran needs to give up its nuclear weapons program in a way that is verifiable. And that's our position. ... The end result has to be that the international community, the P5-plus-1, is confident that Iran has given up its nuclear weapons program."
The real question is whether Iran, monitored by U.N. inspectors, can be trusted to enrich uranium only to the level necessary for producing nuclear power or whether enrichment efforts would be shifted to secret sites, enabling it to produce weapons-grade material.
Kerry called the P5-plus-1 meeting "constructive."
"Needless to say, one meeting and a change in tone, which was welcome, doesn't answer those questions yet, and there's a lot of work to be done," Kerry said. "So we will engage in that work, obviously, and we hope very, very much -- all of us -- that we can get concrete results that will answer the outstanding questions regarding the program. But I think all of us were pleased that the foreign minister came today, that he did put some possibilities on the table."
In a commentary for the Center for Strategic and International Studies, security analyst Anthony H. Cordesman writes the United States must be very careful in its negotiations.
"The wrong negotiation could allow Iran to move to the point where it has enough fissile material for a weapon, and/or improve and disperse its centrifuge and other nuclear capabilities to the point where even a U.S. -- much less an Israeli -- preventive strike would no longer credibly degrade Iran's weapons program," he said.
"It could also further weaken the trust of our Arab allies, Israel, Turkey and European states at a time when many feel the United States has failed to take the right sides in Egypt, has shown serious weakness and indecision in dealing with Syria and Iraq, suffers from war fatigue, and cannot find a meaningful solution to its internal debates over its budget and defense spending. These reservations already range from popular conspiracy theories that the United States intends to betray the Arab world for Iran, to serious distrust by every friendly Arab government.
"As long as any negotiations that follow are realistic in terms of their content, and do not endorse indefinite delay in a U.S. response while Iran's nuclear programs move forward, they offer what will be the last real hope of avoiding preventive strikes or a process of containment that would lock the region into an Iranian-Israeli nuclear arms race, a probable Saudi effort to acquire its own nuclear weapons, and a U.S. commitment to extended deterrence."