U.S. Secretary of State John Kerry and Iranian Foreign Minister Javad Zarif have built a personal trust that has enabled diplomacy to begin overcoming decades of distrust, but this promising U.S.-Iranian relationship remains fragile and could disappear once a new president takes office, warn Trita Parsi and Tyler Cullis.

By Trita Parsi and Tyler Cullis

Doubting the power of diplomacy is like doubting climate change at this point. Despite the skepticism Barack Obama faced in the 2008 elections for his willingness to talk to adversaries — including accusations of naivetÃ© from Democratic and Republican rivals alike, Obama’s diplomacy has now both prevented a disastrous war with Iran and an Iranian nuclear bomb and has secured the release of American prisoners held in Iran.

And much more can be achieved if America stays the course — the question is if it can when so much of this success has been built on specific personal relations that have been forged. Since this new budding relationship with Iran has not been institutionalized, what will be left of it when the Obama administration leaves office?

Having established a reliable channel of communication between the two countries for the first time in more than three decades, the Obama administration can explore opportunities that have been unavailable to previous administrations. For Obama — who has long argued that the U.S. should be able “to test the possibility that engagement leads to better outcomes” — sailing into such uncharted waters with Iran affords a ripe opportunity to shape a legacy that is growing by the day.

The challenge is to ensure that these channels of communication are not limited to the personal rapport that has developed between U.S. Secretary of State John Kerry and Iranian Foreign Minister Javad Zarif, but will survive into succeeding administrations. Failing to formalize the channel could not only undermine the very real opportunities that spring forth from such direct U.S.-Iran engagement, but could also implicate the sustainability of the nuclear accord itself.

The most natural step — normalizing relations and reopening embassies — is not in the cards for now. But there are measures the U.S. and Iran can take that could help institutionalize this critical relationship.

Step 1: The U.S. and Iran need to establish a strategic dialogue through regular meetings between their respective government agencies.

This will not be a negotiation between the two, but rather a dialogue on various issues of common concern, though not necessarily of common interest.

The main purpose of this dialogue is to better understand each other’s motives in order to preempt misperceptions and misunderstandings. And of course, if areas of common interest can be found, the dialogue provides an opportunity to explore collaboration on those issues.

In 2003, the Iranians offered a three-step negotiation road map for the U.S. and Iran. One of the suggested measures was a strategic dialogue just of this kind. The George W. Bush administration ignored the proposal.

Had the Bush administration accepted the invitation for dialogue, the Middle East would likely look very different today. The U.S. and Iran may have collaborated rather than competed with each other in Iraq — as they did in Afghanistan before President Bush included Iran in the Axis of Evil. If they had cooperated, that may have prevented the collapse of the Iraqi state and the spread of sectarianism. The world may never have known the scourge of the so-called Islamic State, and Syria might not have devolved into a civil war seemingly immune to resolution.

Missing that opportunity in 2003 proved tremendously costly for all sides. Missing it after 2016 may prove even costlier.

Step 2: The legislatures of both countries need to establish their own dialogue.

Some of the harshest opposition to improved U.S.-Iran relations is currently concentrated within the U.S. Congress and the Iranian parliament. The only prospect of undoing some of that mistrust is to begin a process of dialogue — just as the nuclear deal began with discreet talks between American and Iranian officials in Oman.

Ideally, this process will eventually lead to congressional delegations visiting Iran and vice versa and provide the legislatures a formal role in the strategic dialogue between the two countries.

Step 3: Perhaps most importantly, there needs to be increased contact and communications between the two societies.

Whether connections between American and Iranian think tanks or non-policy oriented people-to-people exchanges, such activities have been almost nonexistent in the past three decades.

Here, the problem has primarily been on the Iranian side, where the government has viewed such activities with great suspicion. Just in the past months, there has been a crackdown inside Iran on individuals engaged in such bridge-building. For people-to-people contacts to flourish and enable the two societies to rediscover each other, the bridge builders must feel safe.

While the Obama administration has always spoken about diplomacy with Iran as limited and transactional, the events of the past few weeks show this dialogue has the potential to become transformational. But for that to happen, it cannot be limited to Obama and Rouhani or Kerry and Zarif.

True opportunities to start a dialogue between the U.S. and Iran have only appeared once a decade. Opportunities to change the paradigm of the relationship may only come once a generation.