Occasionally, congressional testimony can be interesting in ways unintended by the staff who invited the witnesses. On January 28, the House Foreign Affairs Committee invited Gregory Jones of the Nonproliferation Policy Education Center to testify in a hearing on implementation of the Iran nuclear deal agreed to in November 2013. Jones’s testimony was interesting, and likely not what the majority wanted to hear. But his words do highlight what is not realistic to demand in the negotiations with Iran.

The Nonproliferation Policy Education Center is well-known for its absolute opposition to non-nuclear-weapon states’ possession of “any materials or facilities that can quickly provide fissile material for nuclear weapons,” as Jones put it during the hearing. The purity of this position extends to calling for “shutting down” facilities that enrich uranium “not only in Iran but also in Germany, the Netherlands, Brazil and Japan” as well as facilities in Japan that separate plutonium from spent nuclear fuel.

This was not the most interesting part of Jones’s testimony. (Though, if committee members had asked how the United States or anyone else really could induce all non-nuclear-weapon states to give up fuel-cycle programs, they might have stumbled upon reasons why Iran will not agree to abandon all of its enrichment capabilities.) Even more interesting were the corollary analyses of the Iranian challenge that followed.

Jones acknowledged that President Barack Obama and others recognize that the ideal outcome of ongoing negotiations over Tehran’s nuclear program would be Iran’s agreement to stop all uranium enrichment and to dismantle its enrichment facilities. The problem is that Obama and many others think this demand is unrealistic because Tehran will not agree to it.

Here Jones took a curious turn. He did not dispute the assessment that Iran will not dismantle its enrichment program. Rather, he asked whether it is “any more likely that Iran will agree to [a] large-scale reduction of its centrifuge enrichment program”—the comprehensive solution the United States and its negotiating partners seek. Jones implied that the answer is no. Yet, he did not elaborate on why this conclusion should be made preemptively before negotiations have been given a chance.

Setting aside the problematic conflation of the two options—pursuing the complete dismantling of Iran’s enrichment program or its limitation—Jones then explained his pessimism. Additional sanctions, as advocated by many in Congress, will not succeed because Russia, China, India, and other states will not go along. “With such an attitude by non-Western countries,” Jones averred, “it is unlikely that U.S. and EU sanctions will have the necessary bite to compel Iran to give up its uranium enrichment program.” (Note, again, that he did not address whether sanctions could help motivate Iran to accept significant limits on this program.)

Nor will military strikes on Iran work, said Jones. As he noted, “Iran’s enrichment program is already well into a zone of immunity with regard to a single air strike” of the sort Israel conducted on Iraq and Syria. Iran could readily reconstitute its enrichment capabilities after an attack. Moreover, the “combined volume” of Iran’s already-extant stockpiles of 3.5 percent and 19.7 percent enriched uranium “is less than two cubic yards—making them very easy to hide or protect.” Months of intermittent bombing by the United States could do much more damage, but Iran could still play hide-and-seek, Jones said, and “a prolonged bombing campaign would run a serious risk of turning into a large-scale war with Iran.”

The inadequacy of sanctions and warfare to eliminate Iran’s enrichment program is probably not what the majority of the committee wanted to hear. To his credit, Jones honestly followed the logic of his analysis and concluded: “There are no good options to head off a nuclear-armed Iran.”

Then Jones took another interesting turn. With or without a nuclear deal, he argued, Iran will not “become an overt nuclear weapons state in the near future.” This, too, was probably not what the majority wanted to hear. “Iran is likely taking the long view,” Jones said. “If the negotiations on the Comprehensive Solution fail, then Iran can quickly resume producing 20% enriched uranium and expanding its centrifuge enrichment facilities. If the negotiations succeed, Iran can claim the prize of having international approval of its possession of centrifuge enrichment, wait out the term of the restrictions of the Comprehensive Solution and then greatly expand its centrifuge facilities giving Iran easy access to the HEU [highly enriched uranium] for nuclear weapons.”

There are many reasons to believe Jones is correct that Iran will not seek to make nuclear weapons in the near future, even if negotiations collapse. The problem is: without an agreement, Iran likely would expand without constraint the fuel-cycle and research and development capabilities necessary to develop a nuclear arsenal, while stopping short of actually building weapons. And such a hedging-on-the-threshold strategy is simply too threatening for Israel and Iran’s other neighbors to bear, which therefore makes a laissez-faire response intolerable to any U.S. administration.

This is why the absolutist logic of trying to eliminate Iran’s and all other non-nuclear-weapon states’ fuel-cycle aspirations will not work in the four-year term of any U.S. president. Purity has its attractions, but it is not a luxury that statesmen are afforded. The Iranian situation is messy. There is no viable purist option to redress it. In the course of unfolding his analysis of the Iranian challenge, Jones, perhaps unintentionally, gave his congressional hosts an opportunity to disabuse themselves of easy answers, including his own.

The only realistic approach to Iran is to design an agreement with terms that would serve as a tolerable precedent to be applied to other states that now enrich uranium or that could in the future. Such an agreement would provide insurance against a rapid Iranian breakout to make nuclear weapons by tightly conditioning and limiting the scale of Iran’s enrichment activities to those necessary for research and development and for fueling civilian reactors that are actually under construction and do not have foreign fuel suppliers. This would mean that Iran, beyond research and development work, would not enrich more uranium than it would imminently convert into fuel rods for scheduled insertion into reactors. The only such reactor on the horizon would be a low-enriched-uranium-fueled research reactor to replace the heavy-water one now planned near the city of Arak. Tehran also should agree to put its nuclear facilities under irreversible safeguards that would apply if it were to withdraw from the NPT.

An agreement should specify that Iran will not henceforth conduct research and development activities with plausible nuclear-weaponization applications, of the sort the International Atomic Energy Agency (IAEA) identified in the annex of its November 2011 report. Such a delimitation of potential weaponization activities that are inconsistent with a purely peaceful nuclear program is necessary. And it is necessary to buttress international confidence that non-nuclear-weapon states insisting on enriching uranium (like Iran is, or on separating plutonium in cases other than Iran) will not make nuclear weapons.

And because of Iran’s numerous past violations of IAEA safeguards obligations and transparency requirements, Tehran should implement the Additional Protocol, which enhances prospects that international inspectors can detect undeclared nuclear activities, as well as additional transparency measures. The 1997 Model Additional Protocol was designed for less challenging circumstances than those that are known to exist in Iran. Thus, more extensive transparency and verification procedures will be required for some time in Iran, as in other cases in which the IAEA has required additional cooperation to determine that no relevant undeclared activities were occurring. For example, if indications emerge that Iran has conducted previously undeclared research and development activities associated with nuclear weaponization, a joint commission like the one established under the November interim agreement would need procedures for ascertaining the civilian purposes of such activities. Such procedures then could serve as a useful model if circumstances like those in Iran arose in other states in the future.

Tehran may not agree to such measures, as Jones assumes. But if it did, the Middle East and the world would be more secure than under any plausible alternative scenario. And, if Iran refused a reasonable accommodation like the one discussed here, the international community would have a much clearer basis for deciding that more coercive measures should be pursued.