The sycamore trees that line the northern stretches of Vali Asr Avenue in Tehran arch overhead like a canopy. In the winter, their snowy branches frame a view of the Alborz Mountains where Tehranis escape to hike or ski. On a summer day, the leaves filter the sun and smog in the affluent northern neighborhoods, and you can watch the temperature rise by ten degrees as you inch your way southward in the city's infamous traffic toward the heart of old Tehran.

Vali Asr is said to be the longest street in the Middle East; and sometimes it feels like the only straight path in a nation whose course has been highly unpredictable and intensely complicated ever since the 1979 revolution which ousted the secular, pro-American shah and installed a theocracy led by Ayatollah Ruhollah Khomeini. It was on Vali Asr, 18 years later, that young Iranians erupted in joy in the largest spontaneous public demonstrations the capital had seen since the revolution. The immediate cause for celebration in 1997 was the national team's World Cup qualification, but for many it was a belated response to the recent election of a president who promised reform. Mohammad Khatami's victory represented a moment when the country appeared on the cusp of change again. His promises went largely unfulfilled, however, doomed by the intractability of the defenders of Iran's religious orthodoxy—among them the supreme leader, Ayatollah Ali Khamenei.

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For Shi'a Muslims, the phrase 'Vali Asr' symbolizes hope in a just future; for Iranians, the revolution has brought anything but.

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Yet, on the eve of another election in 2009, Iranians returned to Vali Asr in another powerful display of the will of the people. Tens of thousands of Iranians linked arms in a human chain that stretched the full 12 miles of Vali Asr to express their support of reformist candidate Mir-Hossein Mousavi. Less than a week later, however, huge crowds gathered there again, this time to denounce the apparently rigged victory of the incumbent, Mahmoud Ahmadinejad, a man infamous for his bigotry and provocative policies. The protestors' initial chants of "where is my vote?" met with police batons and bullets. The violence that ended the demonstrations, and the show trials and other Stalinist tactics that followed, suggested that the theocracy no longer saw the need for even the fig leaf of semi-orchestrated elections, and instead had devolved to a more naked authoritarianism. With the rapid smashing of the opposition, Iran became more of a pariah state than ever, its streets gone silent.

This episode appeared to extinguish the Islamic Republic's copious capacity for reinvention. But something happened along the way to the latest election, in June 2013: Iran's political narrative once again defied expectations. A brief and unprecedentedly outspoken campaign gave voice to criticisms of the regime that might once have landed some of the candidates in jail. In the end, it was the candidate who appealed most forcefully for a new path who won the presidency, with a resounding majority.

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Like his mentor Rafsanjani a quarter-century ago, Rouhani appears to have been tapped to effect a turnaround—to staunch a crisis and salvage the revolution from its own failings.

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In the aftermath of the vote, throngs of Iranians once again poured onto Vali Asr for spur-of-the-moment street parties. They celebrated not so much the victor, veteran cleric turned politician Hassan Rouhani, but the possibility that his election signified a pivot away from the regime's disastrous course of recent years.

Even if this proves true—even if Tehran is stepping back from the brink of its ruinous battle with much of the rest of the world—there is no guarantee that Rouhani's election will put an end to the uncertainty that has enveloped Iranian politics for more than three decades, or lessen the antagonism between the Iranian leadership and the West. Rouhani campaigned on a slogan of hope and prudence, two commodities that have been in short supply since the 1979 revolution. Delivering on that promise may prove the toughest course the Islamic Republic has yet had to navigate.

From the Reign of the Shahs to an Enduring Revolution

Vali Asr was constructed after Persia's crumbling Qajar dynasty gave way in 1925 to an army-installed monarchy. Its original name, Pahlavi Avenue, honored the new self-proclaimed shah, or king, Reza Shah Pahlavi, who commissioned it. The broad boulevard became the central thoroughfare in Iran's capital, linking the royal palaces and state institutions with the train station that was the anchor of the shah's industrialization effort. Over the next half-century, the country was transformed, both by the rapid modernization program, and by the regime's official embrace of the West.

Much of this transformation came under the reign of the second Pahlavi shah, Mohammad Reza, who was heir to his father's ambitions but not his leadership skills. His initial years at the helm of the state proved rocky. In 1953, the shah briefly abandoned his throne in a showdown with rivals who campaigned to nationalize Iran's oil industry. The leader of this movement, Prime Minister Mohammad Mossadegh, was ousted in a coup orchestrated by Washington and London, after which the monarchy was reinstated and reinforced. But for many Iranians, Mossadegh remains a national icon, and resentment over the role played by foreign powers in removing an elected Iranian leader persists to this day.

Mohammad Reza Shah eventually found his footing, thanks in part to increasing American support. Washington appreciated the value of a reliable, energy-rich ally as a bulwark against Soviet expansion into the Middle East, and the shah hungered for validation and influence. But American-Iranian relations were tempestuous from the start—a peculiar stew of admiration and resentment on both sides. Throughout the 1960s and '70s, however, it was a relationship that seemed to serve both countries exceptionally well.

Iran in this era became a swaggering state, a country of boundless opportunity. While courting superpowers both east and west, Tehran helped to orchestrate the historic transformation of the global oil industry, which transferred control—and profits—of the world's energy resources to the states that owned them. Fuelled by grandiose ambitions and revulsion toward traditionalism, the shah channeled his vast oil profits into a mad dash for modernity.

Along the way, Iran made much progress. Most important—and often overlooked in the post-revolutionary demonization of the monarchy—millions of Iranians achieved a middle-class existence. The country became an international hotspot: Western bankers jostled for Iranian petrodollars; Harvard Business School opened a campus; tourists from around the world flocked to see the ruins of ancient Persia; diplomats clamored for a Tehran posting.

But amid this rapid development, something was lost. Iranian society was in flux: its economy was simultaneously expanding and imploding, its religion and customs were under siege, its traditional channels of influence eroding under the pressure of a state determined to assert its dominance. Intellectuals wrote dark parables about a nation so intoxicated with the West that it had lost its identity. Even as the shah was pouring money into his notion of an ideal society, pockets of opposition were developing.

Eventually, Pahlavi Avenue and Tehran's city center became the locus of another mode of change, this time driven from the streets of Iran rather than from its palaces. Over the course of 1978, protestors gathered here in ever-expanding numbers to vent their frustrations with a political system in which power was concentrated in the hands of a single man.

The upheaval on the streets culminated the following year in the shah’s ouster at the hands of an inchoate coalition of leftists, liberals and Shi’a Muslim clerics. Among the protestors there was little consensus on what ought to replace the monarchy, but they coalesced around Ruhollah Khomeini, a revered ayatollah who had been exiled in 1964 for protesting the shah’s reforms. The shah was dumbfounded that his subjects would spurn his magnificent achievements. “The nation I had led to the threshold of progress, power, and self-confidence lay torn and bleeding,” he wrote in his memoirs, while he himself had been supplanted by a “worn, fanatic old man [who] was repeatedly telling the Iranian people how mean, miserable, and poverty-stricken they were”—a man who represented the very forces of traditionalism he had sought to eliminate.

The shah's disbelief was echoed by much of the rest of the world. Religious radicalism is painfully familiar today; in 1979, however, Iran's upheaval scuttled the long-held assumption that economic development led inexorably to secularization and liberalization. The fall of Iran's monarchy proved to be the first of what would be numerous salvos in a worldwide, multi-generational struggle over the rightful role of Islam in political life.

Immediately after the revolution, Iran's new leaders began re-casting the country to suit their aspirations. Even the street names were not safe. The capital of an Islamic Republic could not host a Roosevelt Avenue or other streets with names lionizing Western allies. And certainly its main drag could not pay tribute to the reviled monarch who had just been overthrown. Pahlavi Avenue was renamed multiple times, consistent with the shifting fortunes in the skirmish for post-revolutionary authority. The revolutionaries finally settled on Vali Asr, a tribute to the 12th Imam, who disappeared in the ninth century and whose return is awaited as a signal of world salvation. For Shi'a Muslims, the phrase "Vali Asr" symbolizes hope in a just future; for Iranians, the revolution has brought anything but.

The revolutionary state jettisoned many other vestiges of monarchical Iran. Gone were the bars and the discos, the Western tourists and businessmen, the short skirts and bikinis, and any other hints of secularism. Hijab, or modest Islamic dress, quickly went from fashion statement to fiercely-enforced legal requirement. Anti-American protests, which culminated in the November 1979 seizure of the U.S. Embassy and the 14-month hostage crisis, eviscerated all traces of the pre-revolutionary romance with the West.

Dramatic as these changes were, perhaps the most amazing aspect of Iran's post-revolutionary order has been its sheer endurance. The Islamic Republic has survived every calamity short of the plague: an invasion and a brutish war; internal insurgencies; the death of its charismatic founder; catastrophes both natural and man-made; and recently an almost wholesale amputation from the international financial system thanks to economic sanctions. Yet somehow the Islamic Republic is still standing.

A Ceremonial Presidency Evolves in the Islamic Republic

Out of the revolutionary chaos, a new system of government evolved. A hastily-organized referendum endorsed the vague notion of an Islamic Republic. In the contentious debate over a new constitution, Ayatollah Khomeini and his partisans pressed to accord ultimate power to an unelected supreme leader, a post assumed—naturally—by Khomeini himself. Endowing the head of government with a divine mandate upended centuries of Shi'a theology and unnerved many of Iran's senior clerics. But the imam's thundering insistence overrode every objection.

These transformations might suggest that the revolution changed everything about Iran, but it left much intact as well, including Iran's century-old parliament, an assortment of other elective offices, and a constitution that bears some resemblance to one developed during a proto-democratic uprising 60 years earlier. Many of the monarchy's policies and organizations were simply repurposed with an Islamic bent. The tensions and contradictions that characterize the Islamic Republic today reflect the uneasy bargain negotiated among the disparate interests that joined forces to oust the shah.

It seems fitting that the presidency provoked real debate among the framers of the new system from the start. During the years that followed, as the regime's partisans jostled for power, this office would serve, variously, as the center of gravity for Iran's democratic aspirations, as a tangible symbol of the revolution's republican intentions and, for the revolutionary elites, as an advantageous perch for influence peddling. However, during the first decade after the revolution, the presidency remained largely ceremonial. Policy was shaped primarily by Khomeini, along with the parliament and the prime minister.

Early occupants of the presidency proved unlucky: Iran's first post-revolutionary president broke with the regime and had to flee for his life; his replacement was killed in a terrorist attack. On the third try, in August 1981, Iranians elected mid-ranking cleric Ali Khamenei as president. The position would serve him far better than his predecessors, eventually launching him into the exalted status of supreme leader, successor to Khomeini.

Khamenei's two terms as president coincided with a desperate time for the fledgling theocracy, when the country was consumed by the "sacred defense" it was forced to mount to fend off the September 1980 invasion by Saddam Hussein's Iraq. The war presented Tehran with an existential crisis, exacerbated by the country's isolation and by the turmoil and purges that had devastated the military establishment. For all its hazards, however, the conflict had an upside for Khomeini. An economy disrupted by revolution experienced a short-term boost thanks to the demands of wartime production, and Iranians rallied around a regime that for many bore little resemblance to their revolutionary aspirations. Amid the sufferings of war, the new state's authority was strengthened, the achievements of the revolution consolidated. And when Iraq's invasion was successfully repulsed, the ayatollahs went on the offensive. Spurning a 1982 ceasefire proposal that promised billions in reparations from the Gulf states, Khomeini continued the conflict for six more years in an increasingly futile effort to topple Saddam. Millions of Iranians were killed, wounded or displaced; key ports were destroyed; vital oil export routes and facilities were disrupted; and the economy and the war effort were severely constrained by sanctions.

Khomeini finally conceded the war's failure in 1988. The decision to accept a cease-fire with Saddam, which he famously compared to drinking from a poisoned chalice, contravened his frequent invocations of victory at any cost, and came over the objections of his own commanders as well as many of the regime's radicals. But Iran had little alternative: challenges from the opposition and on the streets were mounting; its economy was near collapse; and Tehran lacked the money or materials necessary to achieve a decisive military victory. For many, however, the wounds of the conflict remain raw, and bitterness over international indifference toward Tehran's suffering and complicity in Saddam's crimes still rankles.

The politician tapped to bring the war to a satisfactory conclusion was Ali Akbar Hashemi Rafsanjani, then-speaker of the parliament and a cleric who was especially close to Khomeini. Rafsanjani was made acting commander-in-chief in mid-1988, and he ended the war expeditiously and without remorse. Then, when Khomeini died in 1989, Rafsanjani played a central role in boosting his revolutionary comrade Khamenei into the post of supreme leader, while he himself moved seamlessly into the newly expanded presidency.

Rafsanjani's presidency proved decisive for Iran. He came into office determined to enact an ambitious reconstruction program, and his efforts to undertake an economic and diplomatic rehabilitation of his country were hard-fought, if not wholly successful. But his policies sparked waves of resistance—first, from a liberalizing reform movement and then, in counter-reaction, from a new generation of hardliners. Both movements imploded of their own volition, leaving in their wake a country ripe for Rafsanjani-style moderation and pragmatism—which in turn would later lead to a strange kind of comeback for the Islamic Republic's most storied politician.

The 2013 Presidential Election: 686 Applicants, Only Eight Contenders

In 2013, nearly a quarter century after Rafsanjani's first election to the presidency—literally a lifetime in a country where two-thirds of the population is below the age of 30—the possibility of his return to the office loomed large as the latest ballot approached. He had already served two terms, from 1989 to 1997, and had sought a third in 2005, in a tight race against Mahmoud Ahmadinejad, then mayor of Tehran. He lost that contest in a run-off, a defeat that stung the establishment and catapulted the little-known Ahmadinejad into the limelight. Ahmadinejad's presidency reversed the trajectory of Iran's post-war path of moderation, and put the revolution back on a collision course with the international community.

This time around, after months of public vacillation, Rafsanjani arrived to register his candidacy at the last possible moment, creating a perfectly orchestrated election surprise. His dramatic bid captivated an Iranian political establishment that had been in a state of suspended animation for four years, ever since the massive street protests that erupted after Ahmadinejad's dubious 2009 reelection. Not that Rafsanjani's candidacy was universally welcomed. Over the years, the disappointments of his tenure and his reputation for opportunism and corruption had eroded public support, perhaps accounting for the failure of his last two campaigns (a 2000 bid for the parliament as well as the 2005 presidential race). But he remains a heavyweight. And after the havoc wrought by Ahmadinejad, the prospective candidacy of a politician still considered a man of action and substance buoyed hopes for a better future.

Iranian elections adhere to an idiosyncratic set of procedures. While anyone can toss a hat into the ring, a clerical oversight body—the Council of Guardians—determines who is permitted to run. The eligibility criteria are vague enough to enable the regime to cull all but a few hand-picked insiders. In a bizarre turn of events, the Guardians rejected Rafsanjani's bid for another go at the office he had held for eight years. However absurd the Islamic Republic's vetting process has been in the past—and more than two dozen elections over the course of 34 years have provided abundant fodder for ridicule—the ruling that one of the regime's founders was unfit to run for the presidency carried the farce to a new level.

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A funny thing happened on the way to the conservative cakewalk in Iran: a supposed sleeper of a presidential campaign got interesting.

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Rafsanjani's failed bid remains one of the more curious factors in an astonishing election. Perhaps it was simply textbook political theater from the regime's most skilled showman, his snubbing meant to reinforce the need for a return to realism, thus improving the prospects for the candidate closest to his own views and experience—Hassan Rouhani.

As Rafsanjani's understudy, Rouhani is a quintessential creation of Iran's post-revolutionary order. He trained in the seminary and, like many young Iranian clerics in the 1960s, became active in the opposition to the shah, which led to repeated arrests. Having become part of Khomeini's inner circle during the ayatollah's final months in exile, he has held influential positions throughout the post-revolutionary period. But it was his role as a nuclear negotiator, an extension of his 16-year tenure as the secretary of Iran's Supreme National Security Council, that hurtled Rouhani into the eye of the hurricane, and brought him to the attention of the world, which had hitherto taken little notice of him. Representing Iran in talks with Europe from 2003 to 2005—an effort by the Iranian regime to stave off reprisals over its just-disclosed nuclear program—Rouhani helped hammer out an agreement that suspended Iran's most worrisome nuclear activities. To date it remains Iran's most significant concession on the nuclear issue, and it earned Rouhani the nickname "the sheikh of diplomacy" for his role in defusing a mounting clash with the West.

Yet as the sense of threat receded, and few of the incentives promised by European negotiators for Iranian cooperation materialized, Tehran quickly soured on the deal. Having only warily endorsed the 2003 suspension, Supreme Leader Ayatollah Khamenei quashed it less than two years later, resuming the nuclear program and championing defiance in tune with Iran's new president, Mahmoud Ahmadinejad. Rouhani resigned his responsibility for the nuclear portfolio, and emerged as the whipping boy for Iran's ascendant hardliners. In their eyes, Rouhani's diplomacy represented a surrender to the rapacious West, exchanging diamonds for peanuts, conceding Iran's resources and its influence as irresponsibly as the monarchy had.

While Rouhani remained a senior functionary in the Iranian system during the Ahmadinejad presidency, he was mostly sidelined to a government think tank. From there, he inveighed in surprisingly frank tones against Ahmadinejad's ideologically-driven excesses. Sometimes he even appeared to be serving as an informal spokesman for Iran's embattled realists, most of whom had been shunted aside in the wake of Ahmadinejad's giddy arrival on the scene. During this period he also wrote one of the only truly interesting memoirs of recent Iranian political history, divulging new details about the nuclear program, sharing insider gossip and dispensing the blunt truths that are his hallmark.

Rouhani held a strange sinecure on the fringes of official respectability and relevance in these years, publicly excoriated by Khamenei for the nuclear negotiations he had led, yet somehow retaining his close bond with the supreme leader. So it was perhaps not surprising that out of 686 applicants, Rouhani was one of the eight candidates —all of them men of the system, and most of an unabashedly conservative bent— to receive the nod from the Council of Guardians.

The slate elicited little excitement and, after the short-lived commotion over Rafsanjani, many observers anticipated an anodyne campaign, a display of mindless deference to the regime's ideological strictures. Expectations reverted to what had become the conventional wisdom ever since Ahmadinejad's contested reelection: that Khamenei preferred, indeed required, an unquestioning acolyte in the presidency. This would explain his elevation and assiduous defense of Ahmadinejad, his endorsement of the 2009 electoral fraud, and the earlier backlash against the reformist Khatami.

Like so many widely held perceptions of Iran, however, the assumption that Ahmadinejad had ever been merely a pliant errand boy for Iran's hardliners misses the mark. That may have been the intention, but Ahmadinejad eclipsed these expectations and the presidency's limited powers, overturning the revolutionary state's protocols and alarming the establishment. Late in his second term, after he had overstepped one time too often by attempting to fire the intelligence minister over the supreme leader's objections, Khamenei reined him in—which only reinforced presumptions that the supreme leader would not make the same mistake again. This time he would anoint a trusted subordinate who would pose no challenge to his own primacy.

Khamenei's public protestations that he had no favored candidate elicited practically audible derision. Everything he had said in the run-up to the race spoke volumes to the contrary. The supreme leader framed the parameters governing the election in unambiguous fashion: the ballot must be a pro-regime "epic"; candidates must avoid any hint of "concessions to [Iran's] enemies"; and any repeat of the mass unrest that erupted four years earlier would not be tolerated.

Given these criteria, Iran's incumbent nuclear negotiator Saeed Jalili seemed spot-on for consecration. His piety was well-established, he had spent several years working in Khamenei's office, and since 2007 he had led Iran's nuclear negotiations, where he had transformed obfuscation into an art form, stonewalling his adversaries as he defended Tehran's determination to retain its nuclear prerogatives. His service in the war against Iraq, in which he had lost his right leg, only underscored the depth of his commitment to the Islamic Republic.

Jalili's main competition looked to come from another next-generation conservative, Tehran mayor Mohammad Baqer Qalibaf. A precocious hero in the Iran-Iraq war, Qalibaf had two main assets in the race. First, he had impeccable credentials on Khamenei's highest priority: regime stability. In 1999, Qalibaf signed an unprecedented letter by senior military commanders publicly rebuking then-President Khatami over his handling of student protests; Qalibaf even boasted of his own role in cracking skulls during the quashing of those demonstrations. Second, his position as mayor of Tehran bestowed upon him a built-in popular base and a reputation for results on quality-of-life issues.

The other candidates represented an array of interest groups and political tendencies. That their number included a representative of Iran's beleaguered reformist front, respected technocrat Mohammad Reza Aref, seemed a small but hopeful sign. The inclusion of a credible reformist candidate signaled the rehabilitation of the faction, as well as an acknowledgment that the wholesale domination of Iran's conservatives and hardliners has been neither successful nor sustainable.

Ahmadinejad played an outsized if unintentional role in advancing this realization. Outside Iran, the former president is best known for his Holocaust denial and anti-Israeli invective, his unsettling messianism and his wild-eyed ruminations. Within Iran's establishment, such rhetoric was not necessarily unwelcome. But his proclivity for chaos and crisis was, and it alienated even the hardliners who had backed him. Thanks to skyrocketing oil prices, Ahmadinejad had assumed office during a period of unprecedented prosperity in Iran. Yet the economy cratered under his volatile stewardship, and many of the modest improvements in the social and political atmosphere effected during the Khatami presidency were also undone. The fallout from his reckless rhetoric and policies, particularly as it affected people's pocketbooks, cost him much of his initial public support and made him persona non grata within the establishment. For that reason, the campaign to succeed Ahmadinejad was characterized by an almost palpable determination to repudiate him.

An Inconceivable Twist in the Presidential Campaign

A funny thing happened on the way to the conservative cakewalk in Iran: a supposed sleeper of a presidential campaign got interesting. Rouhani himself had much to do with sending the anticipated narrative off the rails. This was a surprise. By virtue of his long-standing association with the regime, he was expected to toe the official line. Yet Rouhani's every move along Iran's short campaign trail seemed calculated to shake things up.

It is difficult to pinpoint precisely when it became clear that Rouhani did not intend to run a cautious campaign. Was it his appeal for the release of political prisoners, including detained reformist leaders Mir-Hossein Mousavi and Mehdi Karroubi, which he made even before his candidacy was approved? Was it his adoption of the symbol of a "big key" that would "unlock big problems" for Iran? Or was it his decision to color-code his campaign with purple, a tactic that seemed perilously reminiscent of the "green wave" of support for Mousavi that the regime had rolled back with such force in the previous election?

It might have been an appearance on state television when Rouhani upbraided an interviewer for misrepresenting his record on the nuclear issue and instructed him to re-read his memoir to get his facts right. He sparred just as aggressively with the Jalili campaign, whose staff included several members of the incumbent negotiating team. For Rouhani to have broached this discussion, knowing how obsessed the leadership is with retaining its nuclear infrastructure and presenting a united front to the world, was a particularly daring move. And dispensing with protocol and the state broadcasters, Rouhani released his campaign video straight to YouTube, where its emphasis on his close ties with Iran's leadership and his own achievements alternated with poetic appeals for a new spring after a long, cold winter.

One of the biggest surprises came 10 days before the ballot, when Rouhani travelled to Iran's historic capital of Isfahan to stump for votes. While there, he joined the mourning procession for a dissident cleric who had penned a public letter a decade earlier that condemned the regime for "deviation, abuse and lawlessness" and described its leadership as "henchmen of tyranny." It did not seem to bother Rouhani that the chants of support for his campaign were interspersed with denunciations of Khamenei and the theocratic system. Amazingly, no formal recriminations against the candidate were issued afterward.

In the end, however, while Rouhani's boundary-bashing may have set the stage, it was a televised debate among all the candidates that really broke the presidential race wide open. The fact that the debates were held at all raised eyebrows. Ahmadinejad's deft and dangerous exploitation of the 2009 debates—when he wielded intelligence files on television as a prop to accuse his rivals of corruption and nepotism—had sparked an uproar. Many expected that the regime would simply dispense with debates. Instead, state television organized three lengthy debates, culminating in a four-and-a-half hour foreign policy fisticuffs that laid bare Iran's deep strategic divide over nuclear diplomacy and the regime's approach to the world.

Rouhani, who had mounted a pugnacious defense of his own nuclear record while on the campaign trail, stayed true to form during the debate, disparaging Jalili as an unsophisticated puritan whose only negotiating skill was verbosity. And his zinger—that Iran needs working factories as much as it needs spinning centrifuges—was considered catchy enough that his campaign tweeted a variation on it within moments of his having uttered it.

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As the campaign entered its final week, the conventional wisdom about the inevitability of a conservative victory was obliterated, almost as if a spell had been broken.

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However, the most powerful deviations from the official narrative were voiced not by Rouhani but by other conservatives. Several questioned why Jalili, the presumptive front-runner, had not secured a deal in talks with the West, and challenged the sense of resistance on the nuclear issue if it came at the cost of keeping Iran's population hungry. Ali Akbar Velayati, the long-time foreign minister who owes his entire career in politics to his close relationship to Khamenei, delivered the most devastating blows. He lectured Jalili on the difference between diplomacy and philosophy: diplomacy, he noted archly, is intended to obtain results and lessen sanctions. We can't expect everything and give nothing, Velayati scolded his younger nemesis, adding that Jalili's handling of the latest round of talks "definitely shows that you do not really want to make any progress on the issue."

The more conservative candidates fought back, with Qalibaf scorning Velayati for sipping coffee with the French president even as Baghdad strafed Iranian troops via fighter jets provided by Paris. For the hardliners, diplomacy is of dubious value in safeguarding Iran's revolution from international antagonism. Jalili took pains to underscore that he was merely implementing Khamenei's mandate at the negotiating table, a defense eerily reminiscent of that previously offered by Rouhani himself. In the context of the election, however, Jalili's insistence that he was following orders only made the attacks on him seem that much more of a mutiny against the unpopular establishment.

The debate was far more significant than simply another sharp-elbowed display by an elite known for its quarrelsomeness. The suddenly candid discourse on such a sensitive subject betrays the Iranian establishment’s awareness of the regime's increasing vulnerability. Nothing like this had ever happened before, and certainly not on live state television, with approximately two-thirds of the country watching. In Tehran’s public rhetoric, the nuclear program represents the nation’s glory as well as its capacity to withstand the “bullying” of the West. Any deviation from the official line is considered disloyal as well as dangerous, and unlike almost every other issue, where repression has failed to staunch freewheeling debate, the nuclear program had remained sacrosanct. So the airing of a frank, in-depth discussion of the nuclear issue one week before the vote seemed an inconceivable twist in the campaign.

The nuclear debate served as the writing on the wall. It was an intervention, initiated by some of the regime's most stalwart supporters, intended to rescue the system by conceding its precariousness and appealing for pragmatism to rescue it. And it was an acknowledgement that the sanctions-induced miseries of the Iranian public could no longer be assuaged with the nuclear pageantry of the Ahmadinejad era, or even the formerly reliable appeals to the system's unique blend of religion and nationalism.

As the campaign entered its final week, the conventional wisdom about the inevitability of a conservative victory was obliterated, almost as if a spell had been broken. Two final developments sealed the election's outcome. Working on the sidelines, Rafsanjani hammered out a painstaking truce with the reform faction, headed by former president Khatami, which eased the departure of the only real reformist in the race, Mohammad Reza Aref. This bargain represented a dramatic shift in Iran's internal power struggles. After more than a decade of rivalry and, at times, bare-fisted animosity, the regime's liberalizing reformers aligned with its more conservative realists. The compact proved key to consolidating a wide swath of Iranian public opinion behind Rouhani.

Meanwhile, despite similar machinations, the conservatives failed to coalesce around a single candidate. Ill-suited to the new environment of truth-telling on the nuclear issue, the campaigns of both Jalili and Qalibaf appeared to falter as the race drew to a close. To generate a conservative victory at this stage would have required blatant manipulation of the vote, a risk that the regime may not have been willing to take, particularly with many of its neighbors in an unprecedented state of upheaval.

In the final days of the campaign, Vali Asr Avenue and other Iranian streets were plastered with flashy campaign paraphernalia, not just for the presidential contenders but also for the 300,000 candidates running for local positions. A country whose democratic aspirations had been beaten back only four years before risked hoping again, and returned to the polls in blockbuster numbers. And this time Iranians opted to turn the big key. Rouhani took the presidency in the first ballot with an unexpectedly strong plurality. Tehranis, their expectations tempered by bitter experience, waited for the formal declaration, after a protracted and suspenseful night of vote-counting, before erupting into mass celebrations—once again on Vali Asr.

A Lack of Trust on the Nuclear Issue

Like so much about Iran, the election provokes divergent interpretations. Did an ossifying regime accede to overwhelming public demand for more responsible leadership, or did the revolution's hard-nosed stalwarts orchestrate a shift in its center of gravity away from its bellicose extremes? The truth likely lies somewhere in the middle; in other words, the election was another untidy improvisation by a regime that is acutely aware of its own vulnerabilities and has made an art form of survival under the most inauspicious circumstances.

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This is a moment of tremendous opportunity for Washington, although it offers no easy answers. In fact, Rouhani's very moderation may make things harder by eroding international support for sanctions and in turn stiffening the spines of Iran's hardliners.

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For a usual suspect, Iran's new president is an unusual character. Beyond his seminary studies, he also received a degree from Tehran University and pursued a doctorate in constitutional law at Glasgow Caledonian University, even as he climbed the ranks of the bureaucracy in a theocracy that had little use for European credentials. When much of the Iranian elite did little more than grumble about Ahmadinejad's provocative policies, Rouhani boldly denounced his recklessness and highlighted the costs to the economy.

Like his mentor Rafsanjani a quarter-century ago, Rouhani appears to have been tapped to effect a turnaround—to staunch a crisis and salvage the revolution from its own failings. But his past political affiliations lie closer to Iran's traditional conservatives than to the leftists who spearheaded the reform movement 15 years ago. In seeking to transcend the trap of partisanship, however, he argues that he represents the "reasonable faction," which he describes as being made up of all those Iranian politicians who are interested first and foremost in problem-solving.

This is a moment of tremendous opportunity for Washington, although it offers no easy answers. In fact, Rouhani's very moderation may make things harder by eroding international support for sanctions and in turn stiffening the spines of Iran's hardliners. Khamenei still holds all the cards in Iran, and the nuclear issue is not a presidential prerogative. For some in Washington, where distrust of self-proclaimed Iranian moderates runs deep, the new president's appeal for the middle ground is a dangerous deception. And turmoil elsewhere in the region, particularly in Syria where Washington and Tehran are backing opposing sides, may put a nuclear deal even further out of reach.

Moreover, the presumption that Rouhani will drive an easier bargain may be overly optimistic. The Europeans who sat across the table from him during his time as Iran's nuclear negotiator remember him as a tough customer. And his recent track record underscores the difficulty of expecting too much from Rouhani on the nuclear issue. The only recent progress on this issue came in 2009, with a tentative agreement to export much of Iran's enriched uranium in exchange for Western-supplied fuel rods for its medical research reactor. Ironically, the primary Iranian proponent of this arrangement was Ahmadinejad, whereas Rouhani played a vocal role in scuttling the deal, which he described as "illegal," a "mistake," and a Western attempt to deprive Iran of its uranium stockpile. These criticisms helped persuade Khamenei to back away from an initial acceptance of the agreement, sending Iran further down a path of international isolation and pressure.

On the merits, the nuclear crisis need not be intractable. Washington could tolerate some low-level enrichment in Iran, so long as its scope is capped and an inspection regime to ensure absolute transparency is implemented. Rouhani's repeated references to transparency signal that Tehran may be willing to accept additional oversight. With regard to Iran's repeated insistence that the West acknowledge its self-described "legitimate rights" to the full fuel cycle under the Nuclear Non-Proliferation Treaty (NPT), some diplomatic sophistry and rhetorical creativity should be able to facilitate a mutually acceptable formulation.

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Though no one can say for certain what the Rouhani era will bring, now that an election that was expected to consolidate authority in the hands of defiant theocrats has unexpectedly opened a tentative door to conciliation, we are hoping that the tide has turned at last. Clearly many in Iran harbor that same wish.

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Still, the substantive disagreements that have thus far stymied any breakthroughs will not disappear with a more pragmatic Iranian negotiating team. It will be an uphill battle to persuade Tehran to put strong enough limits on the size and scope of its nuclear program in sufficient fashion to reassure the international community. Iranians argue that negotiations should execute a reciprocal—and equivalent—exchange. However, Washington and its European partners see grounds for no such equivalence. For them, Iran is the transgressor, having concealed its nuclear activities for 18 years and having failed for more than a decade since their revelation to fully adhere to NPT safeguards obligations or satisfy U.N. Security Council demands. Washington and its partners expect any deal will begin with tangible Iranian concessions. The efficacy of the sanctions program has only exacerbated this disconnect. With Iran having paid such a high price for its nuclear ambitions, Iranian officials may now demand a commensurately large reward in exchange for constraining the program.

The fundamental obstacle to real progress is the lack of trust between the two sides—validated by their respective historical narratives and exacerbated by their contentious domestic politics. Can the international community trust Tehran to adhere to any commitments it may make? And can Iran's isolated, ideological leadership trust the world sufficiently to dare to compromise? Both Iran and America now have presidents who campaigned on the idea of hope, but as Iran's nuclear program continues to advance, it will take more than hope to build confidence in each other.

Rouhani, The West and the Road Ahead

Three decades of rule by a revolutionary Islamic regime has generated a political reality that in many ways fails to conform to the ideological imperatives of its founders—or, for that matter, to the one-dimensional depiction that has become entrenched in the Western imagination. Iran remains a place of jarring contradictions. It is at once an autocratic system, governed by the whims of a ruler who claims a divine mandate, and at the same time a fractious country shaped by factional competition and the institutions of representative rule. Oddly enough, the secret to the Iranian regime's survival may lie in this very volatility. The dual and dueling institutions of the Islamic Republic are in its DNA, inciting the power struggles that ultimately determine Tehran's decisions. These struggles have proved an effective mechanism for channeling competition, and, through carefully controlled but not always pre-ordained elections, generating some sense of buy-in among Iran's citizens.

Despite substantive changes during its 34-year history, the Islamic Republic has yet to fully embrace the moderation that should herald the twilight of the revolution.

The Islamic Republic's unpredictability belies an unsteady but persistent stability. When the devastating sanctions that were the byproduct of the nuclear crisis threatened this equilibrium, the system stepped in to right itself again, and there is now reason to hope that the crisis can be managed to the satisfaction of both Iran and the West.

But, there is also reason to worry that this self-correction will not happen. We expect revolutions to diminish in fervor, to modulate fiery tenor and rationalize unconventional policies, once the chaos and violence that accompanies any sudden change has subsided. The Iranian Revolution has not followed this model. Despite substantive changes during its 34-year history, the Islamic Republic has yet to fully embrace the moderation that should herald the twilight of the revolution. It is still too soon to say if Rouhani's election will be the harbinger of a durable Thermidor for Iran's theocracy.

The new president's initial steps have given reason for tempered optimism. Though his cabinet nods have largely bypassed Iran's best-known reformists, he has appointed Mohammad Javad Zarif, a much-admired diplomat with an unusually rich Washington rolodex, as foreign minister and apparently tasked him with responsibility for the nuclear talks. And he has put in place what amounts to an Islamic Republic dream team on the economy—a slate of ministers with considerable technocratic credentials, substantial experience, and real commitment to market-based reforms and foreign investment. Perhaps most important, even in his earliest official moves, President Rouhani has reinforced the perception that his election is intended to serve as a conduit for resolving the nuclear standoff. He invited former European Union foreign policy chief Javier Solana—who negotiated with Tehran for years on the nuclear issue—to attend his inauguration, and he has continued to advocate negotiations with Washington on the basis that diplomacy can produce a worthwhile resolution to the crisis.

Anticipating how Iran's story will unfold from here is impossible. Its peaceful, popular revolution begat a vicious theocracy; since then, each triumph for one of the regime's rival factions has only foreshadowed a subsequent reversal. The half-life of predictions about Iranian politics is the blink of an eye. Perhaps that accounts for America's fascination with Iran's fate. Iran is the country whose break with the West ended our innocence about the world's affections, and whose government has kept our own leaders up at night for more than a generation. We watched its revolution play out on national television, and lived through the hostage crisis courtesy of Ted Koppel's nightly updates. We have followed the roller-coaster ride of its political turmoil, worn green in solidarity with its short-lived opposition movement, and jeered the loathsome Ahmadinejad in late-night parodies.

Though no one can say for certain what the Rouhani era will bring, now that an election that was expected to consolidate authority in the hands of defiant theocrats has unexpectedly opened a tentative door to conciliation, we are hoping that the tide has turned at last. Clearly many in Iran harbor that same wish.

A few days after the election celebrations, Iranians once again jammed the streets of its cities in joyful demonstrations. The national team had qualified for the World Cup and, just as in 1997, the confluence of the two successes—on the playing field and in the political arena—seemed almost too good to be true. Iranians have been hardened by disappointments and reversals; they know that the path of political change will be long and circuitous. Still, they take their victories where they can and, in the cool of a summer evening, hope stretches all along Vali Asr, from one end of Tehran to the other.

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Like other products of the Institution, The Brookings Essay is intended to contribute to discussion and stimulate debate on important issues. The views are solely those of the author.