STOCKHOLM — If the West wants Iran to be part of the solution to the crises in the Middle East, it needs to engage with Iran directly. Dialogue has so far been restricted to the nuclear issue. But recent progress in the talks — amid worsening regional turmoil — makes failure to reciprocate Iran’s outreach a missed opportunity.

The Iranian foreign minister, Mohammad Javad Zarif, has made clear that Iran is willing to talk about issues “far beyond nuclear negotiations.” His words are not the isolated wishes of a Western-educated moderate. The Iranian leadership, including the supreme leader, Ayatollah Ali Khamenei, is behind him.

Iran’s regional policy is less about gaining allies than it is about depriving rival powers of anti-Iranian allies. This dynamic opens space for mutually beneficial engagement. The question is how to proceed in a manner that reduces conflict, rather than exacerbating it.

The record of Iranian-American coordination in the fight against terrorism has been positive. In 2001, it took only months to overthrow the Taliban and set up a new Afghan government. And last year a new cabinet was peacefully formed in Iraq while the Islamic State’s blitz there was halted.

It is no coincidence that the Iranian point men in these episodes of tacit coordination have been the same. Contrary to popular perceptions, Maj. Gen. Qassem Soleimani, who heads Iran’s powerful Quds Force, is not a hard-liner but a pragmatist. And despite portrayals of Mr. Zarif as his moderate nemesis, the two actually have long experience working together and delivering results. Together, they have devised proposals for Syria and Yemen built on cease-fires, national dialogue and establishment of inclusive governments.

And despite the occasional “Death to America” chants in Tehran, the reality is that the United States has a far greater problem working with Iran. In Washington, Iran is shamelessly used as a political football, and in the Middle East, America is cornered by allies who are anxious that dealings with Tehran will come at their expense.

President Obama’s defense of the nuclear negotiations succeeded thanks to the forceful argument that there are no realistic alternatives. It is now time for Mr. Obama to clarify this reality with respect to the region, too.

On Yemen, he has shown courage and vision by not allowing America’s commitments to its allies to corner him with the false choice of abandoning friends and unconditionally supporting their folly. Critics of dialogue with Iran must now be made to understand that engagement to stabilize the region is not an untimely boon to the Islamic Republic. They must also be made aware of the many interests that the West shares with Iran in the triangle between Kabul, Sana and Beirut.

To make Iran part of the solution in the region, Mr. Obama should first end the decades-long “no-contact” policy and put the onus on Iran to back up talk with action. Despite all the recent negotiations, American diplomats technically remain restricted from exchanging anything but pleasantries with their Iranian counterparts, without the explicit authorization of the secretary of state.

To improve the chances of engagement, the quality and quantity of communication with Iran must increase. Mr. Obama does not need approval from a hostile Congress to achieve this aim. He can reverse the “no-contact” policy entirely on his own. Having courageously overhauled policy toward Cuba, removing antiquated restrictions that are relics of the 1979 Islamic Revolution and its aftermath would put the onus to engage back on Iran.

Second, the West should lead by example in ending the phobia regarding Iran’s role in the region. Initial steps toward this end must entail adoption of new language. Progress in the nuclear negotiations has been enabled by joint “win-win” discourse. In the regional context, it would be greatly useful to adopt language that portrays Iranian influence as a reality, rather than a reversible nuisance.

Third, the United Nations should be put to good use, if only to provide an umbrella for dialogue. The 2001 Bonn Conference, which prevented civil war and ushered in a new Afghan state, was made possible because it occurred under United Nations auspices and because previous multilateral interactions had brought together America and Iran as well as Afghanistan’s other neighbors and Russia.

Iran prefers regional dialogue to be kept to regional powers. But past precedent indicates that this may not work. In 2012, efforts to establish a contact group for Syria, gathering Iran, Egypt, Turkey and Saudi Arabia, failed because the Saudis refused to sit at the table, fearing that it would legitimize an Iranian role. This dynamic is now being repeated in Yemen, where Iran’s outreach has been rejected on the grounds that “it is not part of the Arab world,” even as Saudi Arabia has requested assistance from Pakistani troops.

Saudi attitudes will likely remain fixed as they primarily serve domestic purposes. Mr. Obama recognizes this, and he has boldly asserted that the greatest threat to Arab states stems not from Iran, but “dissatisfaction inside their own countries.” Sadly, the region cannot wait for America’s allies to address the roots of their anxieties.

Regional dialogue forums must be pursued in the meantime. These should include Egypt, Iran, Saudi Arabia and Turkey plus the United States and Russia. As the nuclear negotiations have made clear, rival veto-wielding Security Council members can move past acrimony and be useful. And a contact group for Yemen could set a precedent for tackling more complex challenges like Syria.

As diplomats sit down to draft a final nuclear deal, the region must consider the benefits of broader engagement with Iran. The West and Iran’s neighbors have nothing to lose, and much to gain.

This article was written by Mohammad Ali Shabani  for the opinion page of The New York Times on Apr 27, 2015. Mohammad Ali Shabani is a doctoral candidate at the University of London’s School of Oriental and African Studies and a columnist for Al Monitor.