As Secretary of State John Kerry and other ministers arrived in Geneva this past weekend, expectations rose that a limited agreement might be reached on the Iranian nuclear program. It was not, but the next meeting is already set for November 20, and while debate is likely to become more intense as to whether a limited agreement makes sense at this time, there is value in taking a step back and asking what might be achieved at this point and what could make it acceptable.

To begin with, it is worth recalling that “freeze for freeze” was a proposal that Javier Solana, representing the European Union, sought to produce in talks with his Iranian counterparts in 2007. The idea was the Iranians would freeze the development of their nuclear program—meaning the enrichment of uranium and production of centrifuges—in return for the freezing of sanctions on Iran. At the time, Iran’s nuclear program had not accumulated even one bomb’s worth of material and its centrifuges numbered a tiny fraction of what they have operating and installed today—and while the Bush Administration supported the proposal, it was not part of the EU three’s direct negotiations with the Iranians.

The freeze for freeze idea was never accepted by the Iranians, even though it was envisioned to be an initial step in a process to reach a wider agreement. Today, a variation of the freeze for freeze idea, also as the first step in a process, may be in the offing. To be sure, the realities are quite different than they were six years ago. Today, the United States is very much involved in the negotiations; Iran has accumulated as much as six bombs worth of enriched uranium, has produced close to 19,000 centrifuges, including more than a thousand of the next generation of IR-2 centrifuges which may be five times as efficient as their IR-1 predecessors; and is building a heavy water plant capable of yielding plutonium. And, of course, unlike six years ago, the Iranians are suffering from the weight of unprecedented economic sanctions.

The deal that was brooded in Geneva and may soon emerge might be described not as a freeze for a freeze but as a “cap for a cap”—meaning that there would be a cap on the Iranian nuclear program and a cap on the sanctions that are being imposed on the Iranians. The Iranians would essentially suspend their enrichment of uranium at 20 percent, begin the process of converting it to fuel or diluting it to a less purified form, and not add to the number of centrifuges they have operating. While the Iranians operate and spin close to 10,000 centrifuges, a little more than half of what they have actually produced, they would not add to their overall number. But they would, however, be able to replace those centrifuges that break down, meaning that the Iranians would be permitted to continue to enrich uranium at the 3.5 to 5 percent level. So enrichment would be capped only at the level that uranium is purified and not by the amount that could still be accumulated.

There is one other important part of the Iranian nuclear program that is still at issue right now in the emerging deal: The heavy water plant the Iranians are building at Arak. The issue seems to be whether all work on it will be suspended for the six months of the “first step” deal. Heavy water would enable the Iranians to have an additional pathway to producing a nuclear bomb—either through plutonium or through enriching uranium to weapons grade. Certainly, if the work on the Arak reactor is not suspended, the Iranians could continue down the path that would enable them to finish the plant by the end of 2014; once on-line, the plant could not be attacked without releasing Chernobyl-type radiation into the surrounding area and atmosphere. Indeed, the reason the Israelis attacked the Osirak reactor in Iraq in 1981 and the Syrian reactor at al-Khybar in 2006 before they became operational was to avoid the possibility of radiation releases.

In short, the emerging deal is one that would cap but not limit all of the Iranian nuclear program. In return for that, the sanctions regime would not be lifted, but a part of it would be relaxed. While the sanctions that restrict the Iranian ability to sell their oil and conduct normal financial transactions would not be touched, the Iranians would be allowed to access, perhaps as much as $15 billion of its hard currency in foreign banks, trade in gold and precious metals, and apparently be able to import limited materials for some of its domestic industries.

One other point about the emerging deal: it is designed to be the first step in advance of reaching what might be described as an agreed definition of the civil nuclear power that Iran would be permitted to have. For the United States, the key is to ensure that the Iranian nuclear program would not leave Iran in a position in which it would have a break-out capability that would permit it to move quickly or at a time of its choosing to produce nuclear weapons. For the Iranians, they would be able to enrich, and the restrictions on their program would not single them out or undo their basic achievements. In theory, it ought to be possible to bridge the gaps if the Iranians are actually willing to have only a demonstrably peaceful nuclear capability.

At this point, it appears that the Obama Administration and its partners in the negotiations believe that President Hassan Rouhani and Foreign Minister Zarif are willing to curtail the Iranian nuclear program but cannot, at this stage, go as far as we need them to go in extensively rolling back their nuclear infrastructure—and we cannot lift the crippling sanctions on them unless they do so. On the one hand, we need time to negotiate a more far-reaching agreement—or at least test whether it is possible; on the other, we don’t want them to continue to advance their nuclear program in the intervening period. The so-called first step agreement is, thus, designed to buy us time by capping or limiting the Iranian nuclear infrastructure and development; in return for accepting such a cap, the Iranians would get a limited relaxation of sanctions. The Administration believes that we retain our leverage because the core sanctions regime will remain in place and the Iranian economy cannot recover without ending that regime.

And here is the rub with the Israelis and others in the Middle East: They fear that the limited relaxation of sanctions will quickly erode the sanctions regime. Notwithstanding our claims that the sanctions architecture will remain in place, there is a widespread belief in the Israeli security establishment that many governments and their private sectors will see an opening and will be convinced that they can and will be able to start doing business again. As they start approaching the Iranians, the Iranians will see that the sanctions are going to fray and they simply need to hang tough and concede no more. From the Israeli standpoint, the first step will thus be the last one and the Iranian program, even if capped, will be at such a high threshold that Iran will have a break-out capability. They see no reason to give up our leverage now and let the Iranians off the hook.

For its part, the Administration believes it is not doing so. It sees the Iranian economic needs remaining great, the limited relaxation can buy Rouhani more political space and the authority to negotiate more—something he must do if Iran is to recover economically at a time when the expectations are again growing among the Iranian public. To dash those expectations won’t just weaken Rouhani but ultimately threaten the regime itself—or so the Administration seems to think. As such, it sees the limited agreement as neither weakening our negotiating position nor the sanctions architecture. Is it possible to bridge this divide in a way that also serves the aim of rolling the Iranian nuclear program back?

I believe so. First, we must be clear that the easing of sanctions will, in fact, be limited and will not affect our enforcement of existing sanctions and those who try to evade them. We will continue to vigorously pursue all loopholes and efforts to work around sanctions. This also means that we must continue to emphasize the reputational costs to any businesses that seek to resume commerce directly or indirectly with Iran.

Second, while the Administration has asked Congress to hold back on adopting new sanctions for now so as not to undercut Rouhani, I think we must also recognize the importance of signaling the Iranians and everyone else that there will be an intensification of sanctions if the diplomacy fails to produce an end-game agreement. Rouhani is president precisely because of the high cost of sanctions. There should be no illusions about what happens if diplomacy fails to significantly roll back the Iranian nuclear program. We don’t do Rouhani any favors if the appearance takes hold that there will be no more sanctions—even if there are no more agreements. From that standpoint, why not accept an approach in which the Congress adopts the next wave of sanctions but agree that they will not be implemented until the end of the six month period of the first step agreement or a clear break down of diplomacy.

Third, at least with our friends who are concerned about what they perceive as our eagerness for any deal with the Iranians—and this perception is held even more deeply among our Arab friends than the Israelis—we should be clearer about what we mean by rolling-back the Iranian nuclear program. I understand not wanting to negotiate among ourselves and not giving away bottom lines, but one reason the first step deal seems so alarming to the Israelis and others is they don’t know what we mean by a bad deal at the end of the day. They seem to think that we are so eager to avoid the use of force, given public opinion, that we will accept anything. We need to let others know, at least privately, that prevention remains the objective and has always meant that if diplomacy fails, force is the likely result. In addition, we should also make clear that we have a number of absolute requirements for any nuclear end-state agreement: Iran must dramatically reduce the number of centrifuges, ship out essentially all of its enriched uranium and, at a minimum, convert its heavy water plant into a light water reactor. In short, we must convey more clearly that we know where we are going on the nuclear issue with Iran.

The benefit of leveling in this fashion is that it puts not only the Iranians on notice but also reassures our friends in the area. That may be especially important at a time when the Administration needs to send a message other than that it is lessening our interests and stakes in the region and has bigger fish to fry elsewhere in the world.