What Nuclear Restrictions Would Be Required for a Viable Iran-Israel Ceasefire?

The requirements for an Iran-Israel ceasefire agreement that could sufficiently reduce the Iranian nuclear threat are numerous and complex, with daunting prospects for success. The regime’s nuclear program is large, with equipment and material spread throughout the country at a wide range of sites. And the more time Tehran has to move residual technology and materials after hostilities end, the greater the chance of diversion to long-term storage or clandestine use. 

Of course, the military campaign is probably far from over, and what happens during the remaining hostilities will affect what Israel, the United States, and other actors believe is ultimately necessary to address the nuclear threat. Yet it is not too early to think about the nuclear elements of a future ceasefire and any durable, negotiated arrangement to come. Other elements—for example, what will happen with sanctions or Iran’s missile program—are deliberately set aside in this analysis to concentrate on the nuclear element, but also require thought.

Ceasefire Implementation

A ceasefire would work best if key parties—particularly the United States, Israel, European partners, and the International Atomic Energy Agency (IAEA)—agree beforehand on the priorities for nuclear threat mitigation and accompanying steps to reduce the dangers from Iran’s program. Otherwise, negotiators may neglect to address troubling features of the program while giving Tehran breathing room to reconstitute its capabilities clandestinely.

Crucially, no one should assume that the need for verification has passed simply because the nuclear program is being pummeled by major military strikes. Key components, materials, and technology may be salvageable from the rubble of destroyed facilities, as may irreplaceable technical data and manuals. Moreover, the postwar environment will be rife with tremendous uncertainties and suspicions. Israel, the United States, and others will suspect that Iran is trying to hide parts of its nuclear program—and if history is any indicator, they will probably be correct. Hence, clear and agreed concepts for how dismantlement, mitigation, and verification will be executed are essential. Failure on this point would only invite future conflict.

The most important nuclear limitations to include in any ceasefire and follow-on agreement would require Iran to do the following:

• Forswear uranium enrichment and reprocessing in perpetuity, with associated infrastructure to be dismantled and verifiably sent outside the country.
• Agree to identify and promptly dispose of enriched uranium stocks that are not already “encumbered” in nuclear fuel for existing reactors.
• Commit not to undertake further cleanup operations at any nuclear site without inspectors present and a disposition path (i.e., plan for removal and disposal) approved in advance. For some of the material, this will mean shipping it abroad.
• Fully identify its weaponization-related material and equipment (including items remaining from its pre-2003 weapons program), and agree to promptly assess and dispose of it.
• Identify technical staff for interviewing, tracking, and redirecting purposes, similar to the scientist redirection programs implemented in Libya and Russia. Also provide access to information on its nuclear education and training efforts.
• Provide a full accounting of the production facilities used to make centrifuges and other components. Commit to the timely destruction of related equipment, as well as any stores of centrifuges.
• Agree to enhanced inspections in perpetuity over a wide range of facilities, including use of advanced verification technology.

The Limitations of Verification

Even if one assumes that the combination of destroying Iranian nuclear sites and establishing verification measures is enough to effectively dismantle the program, the fact that this outcome will be achieved at the barrel of a gun should temper expectations for voluntary Iranian compliance. Moreover, the regime’s acceptance of the terms above will depend on when and how the conflict ends.  A further complication is that Israel has a long record of skepticism about arms-control agreements with countries that are ideologically opposed to its existence. As such, Israeli officials may insist on participating in any onsite inspections in Iran—though it is hard to see how that would work practically without risking future conflict.

Of course, this entire crisis stems from Iran’s woeful track record of complying with international arms-control agreements, nuclear or otherwise. For years, the regime has refused to comply with the obligations of its safeguards agreement with the IAEA. In two resolutions twenty years apart—the most recent passed this month—the IAEA Board of Governors has found Tehran in noncompliance, while multiple reports from independent, professional staff detailed its refusal to cooperate. IAEA officials warn that this noncooperation has left the agency unable to certify the peaceful character of Iran’s nuclear program. Similarly, the United States has long complained about Tehran’s efforts to dodge compliance with the Chemical Weapons Convention by deliberately distorting its obligations. This history suggests that the regime may use implausible legalistic misinterpretations to evade its requirements under any new nuclear verification system. Ironically, only when the United States was party to the Joint Comprehensive Plan of Action (2015-18) did observers chronicle a clear, documented history of Iranian compliance, as certified by both the Obama and first Trump administrations. 

The broader history of international arms control likewise underscores the difficulty of ensuring that Iran does not reconstitute its program. After World War I, for example, Germany was placed under intrusive inspections via the Treaty of Versailles, yet it still engaged in blatant violations that French inspectors were reluctant to call out for fear of provoking a crisis. Germany also violated limits on its forces by training and stationing them in the Soviet Union; an Iranian analogue could involve cooperation with North Korea. 

Later, during the Cold War, the Soviet Union cheated on its arms-control commitments through its biological weapons program and construction of the Krasnoyarsk radar installation. In both cases, the breaches were either undetected or temporarily set aside for fear of provoking a geopolitical crisis. 

Even diligent international inspections might prove insufficient to reassure suspicious powers. For example, after Iraq was defeated militarily in 1991, assessments of its compliance varied and were not helped by the fact that Saddam Hussein did in fact cheat on his commitments. Moreover, Iraqi officials repeatedly behaved in ways that supported allegations they had reconstituted their nuclear weapons program, even when they had not in fact done so—part of the package of miscues and misperceptions that led to the second U.S. invasion in 2003. 

Given these difficulties, continued coercion—namely, the threat of resumed military action or sanctions—will probably be needed to counter Iranian cheating and noncompliance. But successful arms control is more likely when the parties see a geostrategic interest in limiting themselves. During World War II, for example, all belligerents refrained from large-scale use of chemical weapons, and this calculus had as much to do with their fear of mutual use as the treaty obligations they signed after the previous war. More to the point, past cases in which countries dismantled their nuclear programs came when their governments decided that such programs were strategically unwise (e.g., South Africa, Brazil, and Argentina). 

Unfortunately, these examples are unlikely to match the views that Iran will hold at the end of the current conflict. That is, the regime will probably prove unwilling to cooperate in full with limits on its nuclear program unless it decides that the advantages of maintaining peace outweigh the strategic value of maintaining the perpetual threat of conflict. Convincing Tehran to embrace cooperation would be very difficult given the outcomes of its military clashes with Israel since 2024 and its historical enmity.

Policy Implications

The United States should work with Israel, European partners, and the IAEA to identify a common list of ceasefire requirements that include the provisions identified above. This process should begin now as part of a wider negotiations and messaging effort with Tehran. Early IAEA engagement is particularly important because the agency needs to identify its own priorities and address practical considerations such as the cost and composition of wide-ranging inspection teams. These and other postwar verification costs will be substantial—certainly more than the agency’s current budget—so subsidizing them would go far toward enhancing the efficacy of the monitoring effort. Specifically, the United States should work with international and regional partners to finance the necessary verification work as a reasonable price for substantially reducing shared threats.

Washington should also work with partners to formulate and organize the coercive tools that may be necessary to keep Iran in compliance with its commitments, including the triggers for using these tools. In the 1990s, a UN process existed to oversee such efforts, but the Security Council has no role in the current conflict, and tensions with fellow Security Council members Russia and China are higher than ever, suggesting that this path is neither plausible nor necessary. The answer probably lies in a “coalition of the like-minded”—a useful construct that is nevertheless intrinsically vulnerable to political maneuvering and interpretation. 

Ultimately, many of the obstacles to ensuring that Iran does not reconstitute its nuclear weapons program would exist whether or not the regime accepts a new verification regime and feels incentivized to stick with it. Although a ceasefire agreement framed around Iranian pledges of nuclear transparency and cooperation may feel like the triumph of hope over experience, policymakers will have little choice but to take such a deal seriously—if only because it may be the best (or only) option available.

Richard Nephew is the Bernstein Adjunct Fellow at The Washington Institute and former deputy special envoy for Iran at the State Department. Patrick Clawson is the Institute’s Morningstar Senior Fellow and director of its Viterbi Program on Iran and U.S. Policy.