The election of new president Hassan Rowhani in Iran has presented a rare moment of modest optimism, both in Congress and in the administration, for a deal with Iran. But if the moment is not seized, it will be short-lived.

Skeptical observers see the installation of a more moderate president as leading to more stalling by Iran, and will be quick to call for tougher action if a next round of talks does not quickly produce results. The administration should be cognizant of this limited time in its formulation of a stance concerning renewed discussions in the fall, and should begin to build support in Congress now for the presentation of a serious, mutually beneficial offer that represents both a positive show of faith, and a test of Iran’s new president.

In the lead up to Rowhani’s inauguration and beginning of the next round of nuclear talks, there is already a small window of support for diplomacy that hasn’t existed in the past. One example of this is a recent bipartisan effort in the House, launched by Representatives David Price (D-NC) and Charlie Dent (R-PA). The letter, signed by 131 members of Congress, urges the Obama administration to “pursue the potential opportunity presented by Iran's recent presidential election” and expresses the belief that “it would be a mistake not to test whether Dr. Rowhani’s election represents a real opportunity for progress.” Though a seemingly modest effort, the letter represents a rare moment of unity, both within Congress and between Congress and the administration.

This window of opportunity, however, will be short. Israel’s prime minister, Benjamin Netanyahu, has expressed skepticism over the prospect of a deal. In a recent statement, he called president-elect Hassan Rowhani a “wolf in sheep's clothing,” saying the incoming Iranian leader would “smile and build a bomb.”

This view represents a chief concern among conservative lawmakers as well: the new president may represent nothing more than a distraction that will allow Iran’s nuclear program to advance. Both Israeli leaders and U.S. conservatives can be expected to react strongly to any failure to move the ball forward quickly.

But this cycle is nothing new. Each new failure in negotiations between Iran and the west has been met with pressure to react more forcibly. It is nearly two years ago that Jeffrey Goldberg wrote of an impending move by Israel to strike Iran’s nuclear facilities, a threat that, had Iran not chosen to remain shy of Netanyahu’s clearly stated red line, might have already come to pass. If a new round of negotiations in the fall fails to materialize or produces no progress, it is more than likely that we will find ourselves back to heightened tension and renewed threats of war.

This time, however, Iran is much closer to a nuclear weapon. Iran's installation of more advanced centrifuges at its Natanz enrichment facility and its continued accumulation of enriched uranium have shortened the timeline by which the country may be able to “break out.” And while some may argue over the finer points of what we might consider nuclear “capability,” the fact remains that at this point, only one thing is stopping Iran from a race to the bomb, and that is Iran.

The country has chosen to remain on this side of the nuclear red line for now, but few steps remain before its tip-toeing up to or over the edge could trigger a reaction that is impossible to undo. Israel’s threats of action may be dismissed as bluster, but there is no guarantee that when feeling itself backed into a corner, the country will not choose to react—particularly if it feels that the United States is strongly behind it. There is reason for the administration to take this moment of opportunity as its best, and potentially last, chance to negotiate a diplomatic solution to Iran’s nuclear program.

For this reason, it is important that the United States and its allies not be bogged down by misplaced fears that we may appear to be “negotiating with ourselves” by offering a revised position in light of the changes in Iran. A show of faith in the possibilities presented by the mostly democratic election of a more moderate president could be a first step in rebuilding a small level of trust between the two countries that has eroded, even beyond its initially pathetic state, over the course of Ahmadinejad’s two terms.

The terms of the deal an eventual deal are clear: limits to Iran’s enrichment and the implementation of more stringent inspections on its nuclear facilities in exchange for sanctions relief and a recognition of Iran’s right to enrich (something Washington has already acknowledged).

Unfortunately, in sensing Iran’s past inability or unwillingness to compromise, the United States has come to the table with only a small package of sanctions relief. In return, it has received talk of “positive” moves forward from Iran, but no deal, and it is unlikely that they expected much more. Onlookers have realized for some time that a serious offer, including substantial sanctions relief in exchange for equally substantial concessions on the part of Iran, will have to be on offer in order to come to a deal. Due to elections in the United States and Iran and other developments, the time has not previously been ripe for a real negotiation.

Now, that has changed. With a new Iranian president comes a new Iranian perspective. Economic sanctions have taken their toll in Iran, and if nothing else, the election of a more moderate president is a clear signal from the people of Iran that the previous course of action was unsustainable.

There are real signs that the United States and its allies might have reason to be cautiously optimistic for the future of talks. But for this effort to work, the west must be willing to make a bold move. On Saturday, upon news of the Price-Dent letter, Rowhani tweeted approvingly that “131 [U.S.] Congressmen have signed a letter calling on President #Obama to give peace a chance with Iran’s new president #Rouhani.” Later in the day, he announced, again over Twitter, “National Security & Foreign Policy Committee of Iran’s Majlis [parliament] to look into potential change in US approach to Iran.” In this moment of change, there is no such thing as “negotiating with ourselves.”

Both sides must step back, reevaluate, and come to the table fresh, with the hope that each might begin to overcome a history of severe mistrust and move beyond the suspicions of the past. It is only with this level of faith—rooted in a firm acknowledgement that if the United States comes to the table with a serious deal and is rebuked, the administration must reevaluate its position—we can hope to achieve a deal.

Further, this window of hope provides a rare opportunity in which the administration and Congress might speak with a more unified voice on Iran. Rowhani’s reactions make it clear that the moves of both, however small, are being watched closely, whether to build a case for negotiations or for insight into our country’s next move.

In addition to careful consideration of its negotiating position going into the next round of talks, the administration must make a concerted effort to build support for a diplomatic approach in Congress, even if those efforts begin privately. After successfully working together to install the toughest sanctions regime ever in Iran, Congress and the administration must move together to leverage those sanctions and secure a deal.

Ultimately, the risks associated with escalating rhetoric, if the Obama administration makes the decision to sit back and wait for Iran’s next move, are too high in a time when a very real opportunity for change exists. Failure to truly test the waters could result in at best, a longer timeframe for negotiations, allowing for the continued advancement of Iran’s nuclear program. At worst, slow reaction time could lead to a breakdown in talks that pushes the diplomatic process over the edge, resulting in a confrontation that neither side wants. Now is the time to move forward decisively with a deal that will finally bring the issue to a close.

Laicie Heeley is the director of Middle East and defense policy at the Center for Arms Control and Non-Proliferation.

Image: Flickr/Mad House Photography. CC BY 2.0.