A major reason for Iranian diplomats to stand firm on issues related to the JCPOA is their knowledge that their side is the one in the right. It was the United States, not Iran, that reneged on its obligations. Iran’s incremental exceeding, after its year of patience, of some of the limits on uranium enrichment is technically not even a violation, given language in the JCPOA that—as Iranian officials take pains to point out—explicitly relieves Iran of its obligations if other parties do not live up to theirs. Iranians will, like anyone else in a similar position, strongly resist demands to make additional concessions to buy the same amount of sanctions relief they already bargained for with the JCPOA. As Foreign Minister Zarif put it, he will not “buy the same horse twice”—the same aphorism that former U.S. secretary of defense Robert Gates once used in deriding North Korea’s habit of repeatedly demanding fresh economic benefits in return for nuclear and missile restraints that Pyongyang had earlier agreed to.

The JCPOA was laboriously negotiated over the course of several years. Negotiators on each side returned to their capitals knowing they had squeezed as much as they could out of the other side. The agreement represents the limits of what could have been achieved consistent with the legitimate interests of all the parties. Given that the JCPOA and UNSC Resolution 2231 already exist, they now serve as what the late bargaining theorist Thomas Schelling would call a focal point—a salient spot in the bargaining space that suggests itself as a place for agreement in the absence of good reasons to select any other place. If there is to be a new deal within the next year on the Iranian nuclear program and associated sanctions, it will look very much like the JCPOA. Like some of those trade deals the Trump administration negotiated, it will be a fairly small reworking of what is already on the books.

As long as Trump is president, there will have to be just enough difference from what is on the books for him to be able to claim that the new deal is a vastly “better deal.” But if the U.S. administration wants more out of Iran, it will have to agree to more of what Iran wants. President Rouhani said so in his speech to the General Assembly, making clear that Iran would be satisfied with everyone returning to full compliance with the JCPOA but that “if you require more, you should also pay more.” 

The sunset clauses in the JCPOA, which place expiration dates on some of the JCPOA’s restrictions on Iranian nuclear activity, might be candidates for the sort of minor reworking that could go into a new deal. Given how prominently the clauses have played in the rhetoric of American opponents of the JCPOA, any change in them could be rhetorical fodder for the administration to claim a “better deal.” Such a change would be less substantively significant than the rhetoric suggests. What takes place in Iran’s nuclear program several years from now will depend less on the fine print of an earlier agreement than on what Iran and other parties will assess to be in their interests at that future date—just as the Iran that negotiated the JCPOA saw it as in its interests to be integrated into the world economy rather than being a nuclear-armed pariah. Indeed, the Trump administration’s point man on hurting Iran, Brian Hook, has justified the U.S. reneging on the JCPOA by saying that because the deal “has no legal status” and was just “a political commitment by an administration that’s no longer in office,” any other U.S. administration was free to junk the deal whenever it decided the accord was not in its interests. Of course, acceptance of this reasoning would mean applying it also to the other parties to the agreement, including Iran—which will have its own leadership changes in the next few years—making the sunset clauses, by Hook’s logic, meaningless.

In any more-for-more deal, the reciprocal Iranian demand probably would involve greater assurance that the economic benefits of sanctions relief will take place. Even during the Obama administration, the fear among banks and other private sector businesses about inadvertently crossing some still-forbidden lines made the baleful effects of some sanctions live on even after they had been formally lifted. That administration made some good-faith efforts to clarify to the private sector the new rules, but Iran can be expected to insist on more formal and positive steps by the United States to make the process work better next time.

Any attempt to load up a new deal with non-nuclear, non-sanction issues would run into the same problem the makers of the JCPOA faced: grievances of one side would be met by grievances from the other side, and soon the agenda would become intractable. Similarly, demands to do something about Iran’s proverbial “malign, nefarious, destabilizing” behavior would be a problem because such a vague mantra does not translate into a feasible international agreement unless it can be reframed in terms of specific, defensible demands. And any attempt in the current case at such reframing would quickly run into the reality of how much of what Iran does in the Middle East parallels rather than conflicts with U.S. interests (as in combating violent Sunni extremism in Iraq), or is what Iran understandably considers a basic right of tradecraft (as in maintaining its alliance with Syria), or is patently less destabilizing than what Iran’s rivals have been doing (as in the war in Yemen).

Also unfeasible would be any attempt to impose on Iran, and only Iran, restrictions on the development and testing of ballistic missiles. Iran considers its missiles to be an essential deterrent against hostile regional adversaries that not only have ballistic missiles themselves but also can project power through air forces superior to Iran’s own. Tehran has affirmed the role of its missiles as a regional deterrent rather than an extra-regional threat by declaring and observing a 2,000-kilometer range limit. A feasible agreement to curb missile proliferation in the Middle East would require all regional states, not just Iran, to subject themselves to range limitations or possibly other restrictions.

BOTH DONALD Trump and Iran’s current leaders want a deal and want it soon. They might not get it. Any number of developments might occur. Perhaps Trump won’t find a face-saving and politically safe way to back off from the economic warfare that precludes a deal. Or maybe unplanned events such as an accidental military clash in the Persian Gulf will kill needed diplomacy. Or perhaps spoilers who do not want a U.S.-Iranian détente—including the Israeli government and some hardliners in the Revolutionary Guard or elsewhere in the Iranian regime—will devise ways to kill it. Without an agreement that reinstates something like the JCPOA and removes nuclear sanctions, Iran would continue its incremental exceeding of the JCPOA limits, and the specter of an Iranian nuclear weapon would become as prominent a topic as it was before the JCPOA. Renewed talk about militarily attacking Iran would be sure to follow. This would make it more difficult for Iranian leaders to rebut any arguments within their own regime that the specter should become a reality, and that a nuclear deterrent is the only reliable way for Iran to protect itself against its enemies.

If there is no U.S.-Iranian agreement before the U.S. presidential election of 2020, the prospects for such an accord would be better after the election. This would most obviously be true if a Democrat unseats Trump, but the prospects conceivably might improve even in a second Trump term. Freed of election-related dependence on financial backers firmly opposed to doing any business with Iran, Trump might be better able to focus on building a legacy of deals rather than of wars.

Reinstating the JCPOA or something like it would restore a modicum of trust and communication that would make it possible for Washington and Tehran to reach other understandings on other topics, with or without formal agreements. Such progress also would require U.S. policymakers to recognize that the Islamic Republic is not going away any time soon, and that it is a major player in its region—albeit only a mid-level power that does not pose an intercontinental threat to the United States. 

Even with such adjustments, the damage that the Trump administration’s policies have inflicted will take a long time to repair. The hostage crisis that began during Jimmy Carter’s administration, and several other resentment-stoking events during the 1980s such as the U.S. downing of a civilian Iranian airliner, poisoned how Americans and Iranians have seen each other for more than a generation. The poisonous effects of the last couple of years in the relationship are likely to be long-lasting as well.

Paul R. Pillar is a Contributing Editor at the National Interest and the author of Why America Misunderstands the World.