Iran’s presidential election presents a paradox. The vote was free enough for Hassan Rowhani to score a shocking win and for the favored conservative candidate to finish a dismal third. And yet it was blatantly unfair because hundreds of reformist and pragmatic candidates were blocked from running. For policymakers in the US and Europe, this presents a challenge: How should they respond to this remarkable upset victory for Rowhani, who was the eventual candidate of Iranian reformists and is also a regime-approved insider? In answering this question, it is essential that governments don’t just focus on how much influence the new president will or won’t have on the Iran’s nuclear negotiations with the major world powers. What he does to expand individual liberties within the country will be at least as important. To borrow a slogan from President Barack Obama’s first election campaign, this vote was about hope and change. Iranians were deeply disillusioned by President Mahmoud Ahmadinejad’s stolen re-election in 2009. That ballot box theft and the failure of huge popular protests to overturn it made Iranians skeptical of their ability to change anything. Nevertheless, turnout on Friday exceeded 72 percent according to the Interior Ministry, a level the US hasn’t managed in a century.

Under the most difficult political circumstances, Iran’s electorate broke with eight years of Ahmadinejad’s intemperate rule and cast scorn on Supreme Leader Ali Khamenei’s apparatchiks. Voters chose in Rowhani a man who had promised to establish a ministry for women’s affairs, aimed at restoring some of their “trampled rights,” and rejected former nuclear negotiator Saeed Jalili, who said during the campaign that women are best kept as mothers. Rowhani won almost 51 percent of the vote, according to preliminary results, avoiding the need for a run-off. Rowhani’s victory therefore marks a pivotal moment for Iran. He certainly will serve in the shadow of Ali Khamenei, but it is a serious mistake to believe that the new president will be powerless. In the 1990s, both Ali Akbar Rafsanjani and Mohammad Khatami, the former presidents, put their personal stamps on Iranian policy, foreign and domestic. They moderated the bellicose government rhetoric of the 1980s, emphasized economic development (even American oil companies flooded back into Iran), and cooperated with the US and its allies in the early days of the war in Afghanistan. Ahmadinejad came to office intent on confrontation with the regime’s perceived enemies. He dismissed the threat that the international dispute over Iran’s nuclear program would be referred to the United Nations Security Council, and welcomed sanctions as good for the economy. He also deeply embarrassed many liberal-minded Iranians with his denials of the Holocaust and generally crass manner.

Rowhani’s power to shape policy in the two areas of great interest to the US and Europe — Iran’s nuclear program and its assistance to the regime of Syrian President Bashar Assad — will be limited, constraining his ability to deliver on campaign promises to ease tensions and thereby ease Iran’s economic woes.

The Iranian Revolutionary Guard Corps, a parallel military organization to the regular army and a major player in the Iranian economy, is deeply invested in the Syrian civil war, and may even benefit from the smuggling opportunities created by sanctions. The negotiations over the nuclear program, meanwhile, have fallen increasingly under the purview of Khamenei since Rohani led them as chief negotiator in the mid-2000s. The US and Europe need to seize any opportunities that Rowhani creates, putting meaningful sanctions relief on the table in exchange for concrete and verifiable reductions in Iran’s nuclear capability.

If they instead meet any overtures with sullen distrust, Rowhani’s political rivals will use the failure against him.

These geopolitical issues aren’t the only ones that matter, though. Iranians live under an autocratic, repressive and economically stagnating system. Anything that eases those conditions is an unalloyed good. More important, the events of the past several years underscore that evolutionary political change is far preferable, both to its participants and bystanders, to the revolutionary violence witnessed in places like Syria. Rowhani’s regime credentials may allow him to serve as a bridge figure, capable of couching modest reforms terms that are politically acceptable to the hardliners.

It is understandable that we, on the outside, treat geopolitical issues as the litmus tests of Iran’s trajectory. But if Rohani can start renewing and protecting cultural, social and political freedoms, the longer-term effects may be just as consequential for the rest of the world.