Iran’s Secret IAEA Visits: What Nuclear Safeguards Law Allows

Introduction

International nuclear safeguards law permits confidential inspections of Iranian nuclear facilities, including certain inspections conducted without advance notification. However, IAEA inspections in Iran remain subject to the legal procedures established by the country's comprehensive safeguards agreement. Secrecy does not relieve Tehran of its obligations to declare nuclear material, provide required information, and permit independent verification. A confidential visit can contribute to nuclear monitoring, but its legal significance depends on the authority under which inspectors act and the evidence they obtain.

On October 20, 2026, the Arabic-language newspaper Al-Araby Al-Jadeed reported that Iran had preliminarily accepted a proposal involving a secret visit by inspectors from the International Atomic Energy Agency (IAEA). The reported initiative, advanced by Qatar and Pakistan during efforts to revive negotiations between Tehran and Washington, contemplated confidential access to Iranian nuclear sites. The account relied on unnamed sources and did not establish that an inspection had occurred or that the Agency had approved particular verification procedures (Al-Araby Al-Jadeed, 2026).

The proposal raises a question that cannot be answered through diplomatic reporting alone. Iran remains bound by its comprehensive safeguards agreement, INFCIRC/214, which authorizes several forms of inspection. Additional access may also be arranged under appropriate conditions, although it does not automatically reproduce the broader verification powers associated with an Additional Protocol in force.

The distinction has become particularly important following prolonged interruptions in nuclear monitoring. In September 2026, the IAEA reported that it could not determine the current whereabouts or composition of substantial quantities of previously declared enriched uranium. It also identified serious deficiencies in facility information and access (IAEA, 2026, GOV/2026/50). The legal value of any confidential visit must be assessed against these outstanding requirements rather than inferred from the political significance of renewed cooperation.

1. The Reported October 2026 IAEA Visit

The October 20 report described a compromise proposal intended to address competing American and Iranian demands and create conditions for renewed negotiations. According to Al-Araby Al-Jadeed, Qatar and Pakistan had proposed confidential IAEA access to Iranian nuclear sites alongside arrangements involving Iranian assets held in Qatar. Other publications subsequently repeated the account, but the reported terms and the extent of either government's acceptance remained uncertain.

The initiative emerged during renewed Pakistani diplomatic engagement with Tehran. Pakistan's army chief, Field Marshal Asim Munir, visited Iran on October 20, while Iranian officials publicly maintained that negotiations with Washington depended on American concessions concerning sanctions, maritime restrictions, and regional hostilities. Reuters reported these demands on the same day, confirming the wider diplomatic activity without independently establishing that a nuclear inspection agreement had been concluded (Reuters, 2026).

The proposed access was described as secret or unannounced, but those expressions do not identify a particular legal procedure. The reporting did not specify which facilities would be visited, whether inspectors could collect environmental samples, or whether they would have access to nuclear-material inventories and operational records. There was also no publicly established confirmation that the IAEA had accepted inspection modalities under its safeguards authority.

These omissions prevent a definitive classification of the proposal. It might contemplate an inspection authorized by Iran's existing safeguards agreement, supplementary access accepted through a separate arrangement, or a more restricted technical visit. The legal consequences would differ substantially because each possibility involves different rights, procedures, and verification objectives.

The diplomatic setting nevertheless helps explain why confidentiality might be attractive to the parties. Negotiations over an end to hostilities have involved concessions extending beyond nuclear verification, as illustrated by earlier discussions concerning the US–Iran peace deal and the limits of ceasefire diplomacy. Governments may seek confidential arrangements to preserve negotiating flexibility while avoiding immediate domestic or international political costs.

That political rationale does not determine the status of an IAEA inspection. The Agency's responsibilities arise from its Statute, safeguards agreements, and relevant institutional decisions. A proposal negotiated by Iran, the United States, Qatar, and Pakistan cannot independently prescribe the conclusions the Agency may draw or eliminate safeguards procedures that remain legally applicable.

2. Iran’s Obligations Under the NPT Safeguards Agreement

Iran has been a non-nuclear-weapon state party to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) since March 5, 1970. Article II prohibits non-nuclear-weapon states parties from manufacturing or otherwise acquiring nuclear weapons or other nuclear explosive devices. Article III(1) establishes a separate obligation to accept safeguards administered by the IAEA through an agreement concluded with the Agency.

The NPT establishes the obligation to accept safeguards but does not regulate every inspection procedure. Detailed rules concerning nuclear-material declarations, accounting records, facility information, physical access, and verification are contained in the safeguards agreement applicable to the state concerned. For Iran, that instrument is INFCIRC/214, concluded on June 19, 1973, and in force since May 15, 1974.

Article 1 of INFCIRC/214 requires Iran to accept safeguards on relevant source or special fissionable material in peaceful nuclear activities within its territory, jurisdiction, or control. Article 2 establishes the Agency's corresponding right and obligation to apply safeguards for the purpose of verifying that such material is not diverted to nuclear weapons or other nuclear explosive devices. Article 3 requires cooperation between Iran and the Agency to facilitate implementation (IAEA, 1974, arts. 1–3).

These provisions establish continuing obligations independently of temporary political arrangements. Iran's domestic restrictions on cooperation, disputes over nuclear negotiations, and objections to particular inspection demands do not themselves terminate INFCIRC/214. The agreement contains its own provisions governing implementation, amendment, and duration.

Article IV of the NPT recognizes the right to develop nuclear energy for peaceful purposes, subject to the treaty's conditions. Uranium enrichment is not categorically prohibited by Articles II and III merely because the relevant technology can have military applications. Nevertheless, the legality of specific nuclear activities must also be assessed against other international obligations applicable to Iran.

The distinction is particularly significant following the disputed reapplication of earlier Security Council resolutions in September 2025. The United Nations Secretariat and the IAEA treat those resolutions as operative, including provisions requiring Iran to suspend enrichment-related, reprocessing-related, and heavy-water-related activities. Iran, Russia, and China challenge the validity of the process by which the resolutions were restored. That controversy concerns a separate legal basis for restrictions and does not eliminate the obligations established by INFCIRC/214 (IAEA, 2026, GOV/2026/50, paras. 26–30).

Iran's continuing NPT membership must also be distinguished from the treaty's withdrawal procedure. Article X establishes conditions for withdrawal, examined separately in the legal analysis of NPT withdrawal and its consequences. Domestic measures restricting cooperation do not constitute withdrawal under Article X, nor do they automatically terminate an agreement already concluded with the Agency.

2.1 Nuclear Material Accountancy and Verification

The central objective of comprehensive safeguards is the timely detection of diversion of significant quantities of nuclear material from peaceful activities to nuclear weapons, other nuclear explosive devices, or purposes unknown to the Agency. Articles 28–30 of INFCIRC/214 establish the principal objectives and procedures, with nuclear-material accountancy serving as a fundamental safeguards measure.

Nuclear-material accountancy concerns the quantities, composition, location, and movement of safeguarded material. Iran must maintain relevant records and submit information that enables inspectors to compare declared inventories with independent verification results. The Agency may examine material transfers, production records, physical inventories, and related operating information to identify discrepancies requiring explanation.

Containment and surveillance measures provide additional evidence. Seals, cameras, and monitoring instruments may help establish whether nuclear material has moved or relevant equipment has operated between inspections. Their reliability depends on the integrity of the equipment, the continuity of monitoring, and the Agency's ability to evaluate the information produced.

A physical visit does not necessarily establish that all previously declared material remains accounted for. Inspectors may confirm the condition of an installation while lacking information about material transferred before their arrival. The difficulty becomes greater where surveillance has been interrupted or accounting records are incomplete.

Comprehensive safeguards also require examination of the correctness and completeness of a state's declarations. The Agency's responsibilities are not confined to confirming material at declared locations. They extend to investigating indications that nuclear material required to be safeguarded has not been declared, using the legal mechanisms available under the applicable agreement (IAEA, 2025, GOV/2025/25, paras. 4–5).

These functions explain why an inspection may achieve a specific technical purpose without resolving the wider safeguards position. Establishing the quantity of uranium at one facility differs from determining whether all nuclear material required to be declared has been placed under safeguards. The evidence necessary for each conclusion depends on the question being examined.

3. IAEA Inspections in Iran Under INFCIRC/214

Iran's comprehensive safeguards agreement establishes inspection procedures that differ in purpose, frequency, and scope. Articles 70–84 regulate the principal categories and their implementation. The provisions confer specific verification powers rather than unrestricted authority to enter every location associated with Iran's nuclear program.

The legal distinction between ordinary and additional inspection authority becomes important when the Agency considers existing information inadequate. Routine inspections operate through established safeguards arrangements, generally involving declared facilities, designated strategic points, and relevant records. Special inspections provide a mechanism for addressing additional verification needs under specified conditions.

The inspection category determines the applicable procedures, but its label is not sufficient to establish the significance of an individual visit. The Agency must operate within its legal mandate and obtain evidence appropriate to the verification objective. A diplomatic announcement cannot establish that these requirements have been satisfied.

3.1 Ad Hoc, Routine, and Special Inspections

Article 71 provides for ad hoc inspections. These principally concern verification of initial reporting and specified international transfers of nuclear material. Their function is linked to particular safeguards events rather than continuous monitoring of facility operations.

Routine inspections are governed by Article 72. They enable the Agency to verify the consistency of records and reports, confirm the location and composition of safeguarded nuclear material, and investigate possible discrepancies. Their scope is determined by the safeguards agreement and the subsidiary arrangements applicable to the relevant facilities.

Article 73 provides for special inspections where the Agency needs to verify information contained in a special report or considers the information available to it inadequate for fulfilling its safeguards responsibilities. Such inspections may involve additional inspection effort or requests for information and access beyond ordinary inspection arrangements.

Article 77 establishes procedures for consultations where circumstances may require a special inspection. Following consultation, the Agency may undertake inspections beyond routine inspection effort and obtain additional information or access by agreement with Iran. Disagreements concerning the need for additional access are governed by Articles 21 and 22, while Article 18 addresses circumstances requiring essential and urgent action by Iran (IAEA, 1974, arts. 73 and 77).

These provisions distinguish the Agency's authority to seek additional verification from an unrestricted power of immediate entry. The agreement establishes procedures for addressing disagreement, and a state's refusal to cooperate may have consequences under its safeguards obligations. Neither proposition removes the need to identify the applicable inspection power and procedural requirements.

Special inspections also predate the Additional Protocol. Their legal foundation does not depend on that instrument having entered into force. The Additional Protocol provides broader and more systematic information and access mechanisms, but it does not create the special-inspection power already contained in comprehensive safeguards agreements.

3.2 Unannounced Inspections Under Article 84

Article 83 of INFCIRC/214 establishes the ordinary notification requirements for inspections. The applicable period varies according to the inspection category and relevant circumstances. Notification provides information concerning the inspection arrangements, including the facilities or material balance areas involved.

Article 84 creates a qualified exception. It permits the Agency, as a supplementary measure, to conduct a portion of routine inspections covered by Article 80 without advance notification, using random-sampling principles. The provision also requires the Agency to consider relevant operational programs and minimize practical difficulties for Iran and facility operators.

This authority does not permit inspectors to disregard the remaining safeguards procedures. Unannounced inspections remain subject to the agreement's provisions concerning inspector designation, access, and the implementation of safeguards. Article 84 concerns advance notification; it does not establish a general right to inspect otherwise inaccessible locations without the legal procedures applicable to those locations.

Confidentiality from the public is a different question. An inspection may be arranged with Iranian authorities while its precise date or technical findings remain undisclosed. Conversely, an inspection conducted without advance notification must still comply with the safeguards provisions authorizing that activity.

The description of the October proposal as a secret visit does not establish that Article 84 would apply. The reported language could refer to confidentiality surrounding negotiations or to the inspection's timing. Classification requires information about the actual authority and procedures, neither of which was established in the initial reporting.

3.3 Inspection Access and Technical Authority

Article 76 regulates access for different inspection categories. Under ordinary routine arrangements, inspectors generally have access to designated strategic points and relevant accounting records. Strategic points are selected to permit effective verification of nuclear-material inventories, flows, and other safeguards-relevant information.

Articles 74 and 75 identify activities associated with inspection and verification. These include examination of records, independent measurements, observation of sampling, examination of instruments, and checks on containment and surveillance measures. Their purpose is to enable the Agency to assess declarations against evidence rather than rely exclusively on information supplied by facility operators.

Access beyond ordinary inspection locations may require additional procedures. Article 77 provides for consultation and agreement concerning additional information or locations in the context of special inspections, together with mechanisms for resolving disagreement. The scope of an inspector's authority depends on the relevant legal provisions rather than the political importance of the facility concerned.

A limited technical visit may establish the condition of specified equipment or permit examination of particular material. Whether those findings resolve a safeguards deficiency depends on the information already available and the additional evidence required. An inspection of an enrichment facility cannot, without supporting information, establish the disposition of nuclear material previously transferred to another location.

The same principle applies to nuclear-material accounting across multiple facilities. A reliable assessment may require examination of inventories, transfer records, measurements, and operational histories at several locations. Inspection authority must permit the activities necessary for the Agency to reach the relevant conclusion.

4. Confidentiality and Negotiated Inspection Procedures

Confidentiality is an established legal requirement of the IAEA safeguards system. Article 5 of INFCIRC/214 requires the Agency to protect industrial secrets and other confidential information obtained through safeguards implementation. The provision reflects the sensitivity of facility designs, nuclear-material handling, industrial processes, and security arrangements that inspectors may encounter.

Article 5 also regulates disclosure of safeguards information. Communication within the Agency and to its Board of Governors must follow the applicable safeguards and institutional provisions. Individual inspection schedules, technical observations, and detailed facility information are not automatically public merely because they concern internationally supervised nuclear activities.

Confidentiality may support effective verification by protecting legitimate security and commercial interests. However, the Agency must retain the ability to obtain information, evaluate evidence, and communicate findings through the channels necessary for its statutory responsibilities. An agreement to conceal information from the public does not authorize the parties to disregard mandatory institutional procedures.

The IAEA's powers are derived from its Statute, safeguards agreements, and other applicable legal instruments. This reflects the broader principle that the functions and powers of international organizations depend on their constituent frameworks and the competences entrusted to them. Political influence or participation in international negotiations does not independently confer new verification authority.

Qatar and Pakistan may facilitate negotiations, and the United States may seek additional safeguards measures. The resulting political understanding would not itself modify INFCIRC/214. Any arrangement requiring the Agency's participation must be compatible with its legal responsibilities and the institutional procedures governing its activities.

4.1 Exceptional Access Under Article 76(d)

Article 76(d) addresses circumstances in which Iran concludes that unusual conditions require extended limitations on Agency access. It requires Iran and the Agency to make arrangements promptly with a view to enabling the Agency to discharge its safeguards responsibilities despite those limitations. The Director General must report each such arrangement to the Board of Governors.

The provision recognizes that exceptional circumstances may affect the practical conduct of inspections. Damage to facilities, physical hazards, or unusual operational restrictions can require adjustments to access procedures and inspection planning. Such arrangements are intended to preserve verification capability under difficult conditions.

Article 76(d) does not create a general entitlement to suspend safeguards implementation. Its purpose is to accommodate limitations while enabling the Agency to perform its responsibilities. An arrangement that prevents essential verification would need to be assessed against that objective and the continuing obligations established by the agreement.

The provision may be relevant where military damage or security conditions affect access to Iranian nuclear facilities. Its application to the reported October proposal, however, cannot be established from the available description. Nothing in that reporting identifies Article 76(d) as the legal basis of the contemplated visit.

The Director General's reporting requirement also qualifies the scope of permissible confidentiality. An arrangement may remain confidential from the public while still being communicated to the Board as required by the agreement. Protection of sensitive information does not eliminate express institutional reporting duties.

4.2 The 2015 Parchin Inspection Arrangements

The IAEA's verification activities at Parchin in September 2015 illustrate how confidential arrangements may be used to examine sensitive locations. Parchin was a military complex associated with Agency questions concerning historical activities potentially relevant to the development of a nuclear explosive device.

Under the 2015 Road-map for clarification of outstanding issues, Iran and the Agency agreed on arrangements involving visual observation and environmental sampling at the location of interest. The Agency reported that these activities were completed on September 20, 2015. Director General Yukiya Amano and Deputy Director General for Safeguards Tero Varjoranta visited the principal building that day (IAEA, 2015, GOV/2015/68, paras. 52–53).

The Agency stated that it had ensured the samples were taken at the relevant location and maintained their chain of custody in accordance with established safeguards practices. It also reported that the activities were carried out under its monitoring and responsibility. These findings support the use of specifically negotiated verification procedures without establishing an unrestricted precedent for every form of managed or indirect access.

The subsequent technical assessment identified limitations. The Agency observed signs of refurbishment and other changes affecting the building. It concluded that activities undertaken at Parchin since 2012 had seriously undermined its ability to conduct effective verification at the location (IAEA, 2015, GOV/2015/68, paras. 52–57).

Parchin demonstrates that a confidential arrangement can produce evidence considered credible by the Agency while leaving particular historical questions unresolved. The effectiveness of an inspection depends on technical methods, sample integrity, and the availability of evidence relevant to the issue under examination.

The comparison with October 2026 has limits. Parchin involved specific historical questions, while a new inspection intended to account for enriched uranium after a prolonged interruption would require a different combination of material measurements, records, and physical access. The earlier arrangement establishes the practical possibility of negotiated verification procedures, not the adequacy of an arrangement whose terms remain unknown.

5. The Additional Protocol and Voluntary Nuclear Access

Iran's Additional Protocol occupies a separate legal position from its comprehensive safeguards agreement. Additional protocols based on the IAEA's 1997 model were designed to strengthen the Agency's ability to detect undeclared nuclear material and activities. They provide broader declarations and complementary-access arrangements beyond the measures ordinarily available under comprehensive safeguards agreements.

Iran signed its Additional Protocol on December 18, 2003, after its approval by the Board of Governors. The Agency describes Iran's implementation between December 2003 and February 2006 as voluntary or provisional in its official reporting. On January 16, 2016, Iran resumed provisional application under the nuclear arrangements associated with the Joint Comprehensive Plan of Action.

Iran ceased provisional application in February 2021. The protocol has never entered into force for Iran, a distinction reflected in the Agency's legal status records and its September 2026 report (IAEA, 2026, GOV/2026/50, paras. 36–37).

That status does not settle every legal question concerning implementation of the protocol's measures. The IAEA's September 2026 report states that Iran's failure to implement the Additional Protocol is contrary to relevant Security Council and Board resolutions. It also records calls for Iran to implement the protocol and ratify it. The legal force of those demands depends on the instruments in which they appear and must be distinguished from obligations arising directly under an Additional Protocol in force.

The Agency's special-inspection authority under INFCIRC/214 remains separate. It does not disappear because the Additional Protocol is not operative as a treaty between Iran and the Agency. Equally, a special inspection cannot automatically reproduce every declaration and complementary-access mechanism contained in the protocol.

5.1 Complementary Access and Managed Access

The Additional Protocol expands the information a state provides concerning nuclear fuel-cycle activities. The model instrument addresses specified research and development activities, manufacturing and assembly operations, nuclear sites, uranium mining, and other matters relevant to the completeness of nuclear-material declarations.

Complementary access allows the Agency to examine aspects of those declarations, investigate inconsistencies, and strengthen its ability to identify undeclared nuclear material and activities. It differs from routine safeguards inspections in its broader informational scope and the locations that may become relevant to verification.

The model Additional Protocol also establishes notification procedures and provisions for managed access. Article 7 permits arrangements intended to protect proliferation-sensitive information, proprietary material, and legitimate safety or physical-protection requirements. These arrangements must not prevent the Agency from conducting activities necessary to provide credible safeguards assurance (IAEA, 1997, INFCIRC/540, art. 7).

Managed access consequently depends on a balance defined by the verification objective. Sensitive information may be protected through agreed procedures, but the Agency must retain sufficient access and technical independence to evaluate the matters under examination. The protection of confidential information cannot become a substitute for the evidence necessary to support a safeguards conclusion.

For Iran, the model provides a useful illustration of how confidentiality and verification can coexist. However, its provisions cannot simply be treated as currently binding treaty requirements under Iran's unratified Additional Protocol. Any comparable access offered separately must rest on an applicable legal basis and be assessed according to its own terms.

5.2 The Legal Effect of Voluntary Cooperation

Iran may agree to provide supplementary information or access beyond the ordinary arrangements available under INFCIRC/214. Such cooperation may involve specified locations, environmental sampling, review of records, or additional monitoring activities. The legal consequences depend on the arrangement concluded and the obligations already applicable.

A distinction is necessary between cooperation required by an existing safeguards obligation and genuinely supplementary access. When the Agency exercises an authority already established by INFCIRC/214, Iran's cooperation cannot be characterized solely as an optional diplomatic concession. Additional measures beyond those requirements may be arranged separately, subject to the Agency's competence and any necessary institutional approval.

Iran and the IAEA have previously negotiated forms of supplementary verification. Their August 2020 understanding provided for access to two specified locations, while a March 2023 joint statement contemplated further cooperation, information, and monitoring. These arrangements demonstrate that negotiated verification can occur without the Additional Protocol entering into force.

The historical experience also illustrates the limits of promised cooperation. The Agency subsequently reported that outstanding safeguards questions had not been resolved through implementation of the March 2023 understandings. An agreement to provide access has no equivalent evidentiary value to completed verification activities supported by independently assessed information (IAEA, 2025, GOV/2025/25).

The September 2026 Director General's report separately contemplated verification activities connected with a broader political arrangement, subject to requests by the parties and approval by the Board of Governors. Such responsibilities would be additional to the Agency's continuing work under INFCIRC/214 (IAEA, 2026, GOV/2026/50, paras. 17 and 49–50).

The reported October proposal could involve a comparable distinction. Negotiated access might provide information useful for safeguards implementation or for a separate diplomatic agreement. Its legal status would depend on the authorization, agreed procedures, and obligations involved, while any safeguards findings would remain the responsibility of the Agency.

6. Iran’s Outstanding Nuclear Verification Gaps

The IAEA Director General's report of September 1, 2026, GOV/2026/50, identified serious limitations affecting verification of Iran's declared nuclear facilities and material. The report distinguished installations damaged by military attacks from those that remained physically unaffected, while emphasizing the continuing absence of information and access necessary for safeguards implementation.

The Agency reported that, during the relevant period, Iran had not supplied the required information concerning the safeguards status of its declared nuclear facilities and associated nuclear material. Inspectors had also been unable to conduct in-field verification at those locations. Earlier verification activities at Bushehr in June 2026 did not remove the deficiencies documented for the subsequent reporting period (IAEA, 2026, GOV/2026/50, paras. 15, 23 and 42).

The resulting difficulties involved several distinct questions. The Agency lacked sufficient information to determine the current size and location of previously declared enriched uranium stocks. It could not verify the safeguards status of the four declared enrichment facilities and remained unable to resolve separate questions concerning undeclared nuclear material and activities.

These findings describe the position documented in the September report, not necessarily every development that might have followed. They nevertheless establish the outstanding obligations and technical questions against which any subsequent inspection would need to be assessed.

6.1 Enriched Uranium and Lost Continuity of Knowledge

The most immediate verification problem concerns Iran's enriched uranium stockpile. Based on information available before the June 2025 military attacks and estimates derived from previous operating records, the Agency calculated that Iran possessed approximately 9,874.9 kilograms of enriched uranium as of June 13, 2025.

That historical estimate included 9,040.5 kilograms of uranium in uranium hexafluoride form and 834.4 kilograms in other forms. The uranium hexafluoride component included 440.9 kilograms of uranium enriched up to 60% uranium-235, of which 432.9 kilograms had been verified by the Agency (IAEA, 2026, GOV/2026/50, para. 27 and footnote 17).

These quantities are not verified inventories for October 2026. The September report expressly stated that the Agency could not determine the current size, composition, or whereabouts of Iran's enriched uranium stockpile because it lacked information and access to the four declared enrichment facilities.

Uranium enriched to 60% uranium-235 is highly enriched uranium. Its concentration raises serious proliferation concerns because further enrichment could produce material suitable for use in nuclear weapons. Nevertheless, possession of enriched uranium does not itself establish that Iran has manufactured a nuclear explosive device. The legal questions of nuclear-weapons acquisition and safeguards compliance require separate assessment.

The Agency's immediate responsibility involves establishing the status of material previously declared and monitored. Loss of continuity of knowledge means that inspectors can no longer maintain a sufficiently reliable account of relevant material and activities across successive verification periods.

Reconstructing that account may require examination of operating records, material-transfer documentation, physical inventories, and independent measurements. Inspectors may also need to determine whether uranium was moved, processed, converted into another chemical form, or retained at its earlier location.

The Agency identified four declared enrichment facilities whose safeguards status it could not verify: the Fuel Enrichment Plant and Pilot Fuel Enrichment Plant at Natanz, the Fordow Fuel Enrichment Plant, and the Isfahan Fuel Enrichment Plant. Its September report also recorded an inability to verify current centrifuge inventories and relevant manufacturing, assembly, and testing activities (IAEA, 2026, GOV/2026/50, paras. 26–28).

A visit to one facility could establish particular facts concerning equipment or nuclear material at that location. Restoring a reliable account of material previously held across several installations would require evidence sufficient to reconcile the relevant declarations, records, and physical findings.

6.2 Undeclared Material and Outstanding Safeguards Questions

Iran's safeguards deficiencies extend beyond previously declared uranium stocks. The Agency's comprehensive assessment of May 31, 2025, GOV/2025/25, examined unresolved questions concerning nuclear material and activities at several undeclared locations. Its findings were based on safeguards-relevant information from inspections, environmental sampling, satellite imagery, and other sources.

The Agency concluded that Lavisan-Shian, Varamin, and Marivan, together with potentially related locations, formed part of an undeclared structured nuclear program operating until the early 2000s. It assessed that some activities within that historical program involved undeclared nuclear material. These conclusions were based on the Agency's evaluation of the available evidence and Iran's responses.

Turquzabad occupied a different position in the assessment. The Agency concluded that nuclear material, heavily contaminated equipment, or other assets associated with the earlier program had been stored there between 2009 and 2018, after which items were removed. Environmental sampling and other evidence raised questions about the origin and subsequent disposition of material associated with the location (IAEA, 2025, GOV/2025/25, paras. 77–78).

The Agency also stated that it had no credible indications of an ongoing undeclared structured nuclear program of the historical type identified in its findings. This qualification is essential. Evidence concerning past undeclared activities cannot automatically be presented as proof of an equivalent program operating in 2026.

The absence of that particular indication did not resolve the safeguards questions. The Agency remained unable to determine whether relevant nuclear material had been consumed, mixed with declared material, or remained outside safeguards. It also concluded that Iran's explanations and cooperation had been insufficient to settle the outstanding issues.

Iran has disputed the findings and challenged the reliability of certain information supplied to the Agency. Those objections form part of the institutional disagreement, but the Agency's conclusions rest on an assessment of multiple categories of safeguards-relevant evidence rather than a single political allegation.

The resulting legal questions concern the correctness and completeness of Iran's declarations. An inspection limited to Natanz or Fordow would not necessarily establish what happened to material associated with previously undeclared locations. Resolving those matters could require additional explanations, documentation, sampling, and access directed toward the specific unresolved findings.

6.3 The Isfahan Facility and Modified Code 3.1

The Isfahan Fuel Enrichment Plant presents a distinct problem involving early facility information and physical verification. Iran declared the establishment of a fourth enrichment facility in June 2025, but the Agency subsequently reported that it had not received sufficient information to establish the facility's precise location and safeguards status.

In February 2026, the Agency again requested design-information examination and verification at the facility. Its September report stated that inspectors had not obtained the required access and that the Agency could not determine whether nuclear material was present at the installation (IAEA, 2026, GOV/2026/50, paras. 10 and 44).

This dispute engages modified Code 3.1 of Iran's safeguards subsidiary arrangements. The modified code requires design information for a new nuclear facility when the decision to construct or authorize construction is taken, whichever occurs earlier. It also provides for further information as the project develops.

The earlier version of Code 3.1 generally required design information no later than 180 days before nuclear material was scheduled to be introduced. Iran accepted the modified provision in 2003 but later asserted that it could return to the earlier arrangement. The Agency maintains that agreed subsidiary arrangements cannot be altered unilaterally (IAEA, 2026, GOV/2026/50, paras. 32–35).

The legal basis of this position lies in Article 39 of INFCIRC/214 and the agreed subsidiary arrangements. The question is distinct from the Additional Protocol's treaty status. Iran's cessation of provisional application of the protocol does not itself determine whether previously agreed design-information provisions remain binding.

Iran's contrary position must be distinguished from the Agency's institutional assessment. Tehran has treated aspects of its nuclear cooperation as affected by the failure of broader political arrangements, while the Agency considers modified Code 3.1 a continuing legal obligation under the safeguards framework.

The practical consequence is significant. Without early and adequate facility information, inspectors cannot properly plan or conduct design-information verification. Access to another enrichment facility would not resolve this separate deficiency, which concerns the existence, location, design, and safeguards status of the Isfahan installation.

7. Military Attacks, Security Claims, and the Cairo Agreement

The interruption of IAEA verification occurred during military operations affecting Iran's nuclear infrastructure. Israeli attacks in June 2025 targeted several nuclear-related sites, followed by American strikes on facilities at Fordow, Natanz, and Isfahan. The Agency suspended verification activities during the attacks and withdrew inspectors from Iran for safety reasons.

Further American and Israeli military operations began on February 28, 2026. The IAEA subsequently reported additional damage affecting nuclear-related infrastructure, including the Heavy Water Production Plant at Khondab. These developments complicated verification and raised concerns about nuclear safety, facility access, and the preservation of safeguards information (IAEA, 2026, GOV/2026/50, paras. 2 and 13–14).

The legality of military attacks on nuclear facilities raises questions under the prohibition on the use of force and, where applicable, international humanitarian law. Those issues are distinct from the safeguards responsibilities examined here, although the legal boundaries of US military strikes on Iran provide relevant context for the conditions affecting inspection operations.

Iran adopted domestic legislation restricting cooperation with the IAEA in July 2025. Iranian authorities argued that military attacks and continuing threats had made normal safeguards implementation materially impracticable and incompatible with essential security considerations. The Agency acknowledged the dangers created by the conflict but maintained that Iran's comprehensive safeguards agreement remained applicable.

The distinction concerns the continuing existence of an international obligation and the practical conditions under which a particular activity can be performed. Damage or security hazards may make an inspection temporarily unsafe and require alternative procedures. Such difficulties do not, without an applicable legal basis, terminate obligations concerning nuclear-material declarations, records, or cooperation.

Iran's domestic legislation also cannot be treated as automatically altering INFCIRC/214.

The agreement's provisions governing amendment and duration do not authorize unilateral termination through national legislation. The general international-law principle that internal law cannot ordinarily justify failure to perform international obligations reinforces the need to distinguish domestic restrictions from the state's international commitments.

The Cairo agreement of September 9, 2025, represented an attempt to address the operational difficulties. IAEA Director General Rafael Mariano Grossi and Iranian Foreign Minister Abbas Araghchi agreed on procedures concerning inspections, notifications, and safeguards implementation at declared nuclear facilities. The Agency described those arrangements as consistent with INFCIRC/214.

The agreement concerned implementation rather than replacement of the safeguards regime. It provided a procedural means of accommodating exceptional conditions while retaining the underlying verification responsibilities. Its operation depended on cooperation sufficient to enable inspectors to perform the activities required under the agreement.

The arrangement did not endure. On November 20, 2025, Iran informed the Agency that it regarded the Cairo agreement as terminated. The Director General subsequently reported continuing failures to provide information and access concerning declared nuclear material and affected facilities (IAEA, 2026, GOV/2026/50, paras. 5–9).

The Cairo experience is particularly relevant to the October 2026 proposal because it involved negotiated arrangements following attacks on nuclear facilities. It demonstrates that practical accommodations are legally possible, while also showing that agreement on procedures does not guarantee their continued implementation.

An arrangement responding to exceptional conditions must still permit meaningful verification. Its adequacy depends on whether inspectors can obtain the information and evidence necessary for their safeguards responsibilities, not simply on whether a political agreement has been announced.

8. Noncompliance and the IAEA Board’s September 2026 Decision

Iran's unresolved safeguards deficiencies have produced formal decisions by the IAEA Board of Governors. On June 12, 2025, the Board adopted Resolution GOV/2025/38, finding that Iran's failures to cooperate concerning undeclared nuclear material and activities constituted noncompliance with its comprehensive safeguards agreement in the context of Article XII.C of the IAEA Statute.

The Board also found, consistently with Article 19 of INFCIRC/214, that the Agency could not verify that there had been no diversion of nuclear material required to be safeguarded. This institutional finding has substantial legal significance, but it is not equivalent to a determination that Iran possesses nuclear weapons or that a specified quantity of material has been diverted to weapons production.

On June 10, 2026, the Board adopted Resolution GOV/2026/40. It reaffirmed the outstanding compliance concerns, including Iran's failure to provide information and access needed to verify previously declared nuclear material. The resolution reflected the persistence of these deficiencies after prolonged interruptions in safeguards implementation.

The Board adopted a further resolution, GOV/2026/61, on September 9, 2026, by 23 votes in favor, three against, and eight abstentions. It reaffirmed the earlier findings and called upon Iran to remedy its noncompliance by taking the steps considered necessary by the Agency and the Board. It also requested that the Director General transmit the relevant reports and resolutions to Agency members, the United Nations Security Council, and the General Assembly (IAEA, 2026, GOV/2026/61).

These measures arise from the IAEA's safeguards and statutory responsibilities. They must be distinguished from judicial findings concerning Iran's compliance with every obligation under the NPT. The Agency assesses safeguarded nuclear material and related declarations under its mandate; it does not exercise general judicial jurisdiction over all alleged violations of the treaty.

The relationship with the Security Council introduces additional legal requirements. Under Article 25 of the UN Charter, members undertake to accept and carry out Security Council decisions in accordance with the Charter. The legal effects of a particular resolution depend on its operative provisions, context, and the authority exercised. The collective security system under the UN Charter provides the institutional basis for binding measures addressing threats to international peace and security.

Between 2006 and 2010, the Security Council adopted six resolutions concerning Iran's nuclear program. These included requirements to suspend enrichment-related and reprocessing-related activities and specified heavy-water projects, together with sanctions and other restrictions. Resolution 2231, adopted in 2015, subsequently provided for termination of those earlier measures subject to their possible reimposition under the resolution's designated procedure.

France, Germany, and the United Kingdom initiated that procedure in August 2025. The United Nations Secretariat records that the six earlier resolutions were reapplied effective September 27, 2025, at 8 p.m. Eastern Daylight Time. The IAEA's September 2026 report consequently treated their relevant provisions as operative, including requirements concerning suspension and verification of enrichment, reprocessing, and heavy-water-related activities.

Iran, Russia, and China reject the validity of the reapplication process. They argue that the conditions for invoking the mechanism were not satisfied and dispute the legal consequences asserted by the three European governments. Their position is reflected in subsequent Security Council proceedings and diplomatic communications.

France, Germany, and the United Kingdom maintain that the procedure was validly completed under Resolution 2231 and that the earlier measures again bind Iran. The United Nations Secretariat's published position reflects reapplication of the resolutions, although the opposing states continue to dispute that interpretation.

The distinction affects the legal assessment of Iran's nuclear activities. Articles II and III of the NPT do not categorically prohibit safeguarded uranium enrichment, but the reactivated Security Council resolutions contain separate restrictions treated as operative by the United Nations Secretariat and the IAEA. Those restrictions must be identified according to their own legal basis rather than attributed directly to the NPT's general provisions.

The September 2026 Board resolution also expressed support for a diplomatic solution. Negotiated arrangements and independent verification are compatible objectives: diplomacy may create conditions for cooperation, while safeguards findings must remain grounded in the Agency's technical responsibilities.

A confidential inspection could provide evidence relevant to a subsequent Board assessment. It would not automatically reverse existing noncompliance findings, terminate applicable Security Council requirements, or resolve the dispute concerning the status of earlier resolutions. Those consequences depend on the relevant legal instruments and decisions of the competent institutions.

9. What a Confidential IAEA Visit Could Legally Establish

The significance of the reported October proposal depends on the authority under which inspectors would act and the verification activities they could perform. A routine inspection under INFCIRC/214, a special inspection, and supplementary access accepted through a separate arrangement would each have a different legal and procedural basis.

At a declared enrichment facility, inspectors might examine equipment, compare operational records with declared inventories, and conduct independent measurements of nuclear material. Such activities could establish whether particular quantities and forms of uranium were present at the location at the time of inspection.

Environmental sampling might also provide evidence concerning past nuclear activities. The identification of uranium particles can be relevant to questions about enrichment levels, contamination, or material handling. Interpretation requires attention to sampling integrity, the history of the location, and supporting technical information.

These methods can produce reliable findings concerning specific questions without establishing the status of the entire nuclear program. A physical inventory may confirm material present at one installation, while records from other facilities remain necessary to determine whether previously declared quantities have been transferred or processed.

Restoring continuity of knowledge would require particular attention to the interval during which normal verification was interrupted. Inspectors could need to reconstruct material movements using operating records, transfer documentation, surveillance information, and measurements obtained after access resumed. Gaps in these records may limit the conclusions that can be supported.

The Agency's September 2026 findings provide identifiable priorities for such work. Verification of previously declared enriched uranium would require evidence concerning its location, quantities, composition, and relevant processing history. Inspection of the Isfahan Fuel Enrichment Plant would address different questions involving facility location, design information, and possible nuclear-material inventories.

The unresolved undeclared-material questions would require a further category of verification. Findings concerning Lavisan-Shian, Varamin, Marivan, and Turquzabad cannot necessarily be resolved through measurements at declared enrichment facilities. The necessary activities would depend on the specific historical discrepancies and evidence that remained outstanding.

The Agency might also need to assess whether enrichment-related, reprocessing-related, and heavy-water-related activities had ceased, consistent with the requirements it identified under relevant Security Council and Board resolutions. Verification of suspension is a separate task from confirming the physical presence of nuclear material. It may require examination of equipment, facility operations, production records, and relevant locations.

The legal character of access remains important throughout. Where verification is required under an existing safeguards obligation, the relevant procedures continue to govern. Supplementary access may assist the Agency, but the terms of such cooperation must be adequate for the particular objective. A restricted visit cannot establish facts for which the necessary evidence was unavailable.

Confidentiality itself does not prevent a technically meaningful inspection. Safeguards information may be protected from public disclosure while inspectors retain access to the relevant material and records. The Agency's findings must nevertheless be supported by independently assessed evidence and communicated through applicable institutional procedures.

A diplomatic agreement might create favorable conditions for renewed verification without immediately resolving the underlying deficiencies. Iran could allow inspectors to examine one installation while other facilities remained inaccessible. Alternatively, initial access might permit the Agency to identify the further information required for a reliable assessment.

The resulting safeguards conclusions must reflect the evidence actually obtained. A finding concerning a particular inventory, facility, or historical activity cannot be extended automatically to all nuclear material and activities in Iran. Broader assurance requires sufficiently complete declarations, appropriate access, and resolution of significant outstanding inconsistencies.

Sustained verification is especially important after a prolonged interruption. Reliable accounting records, continued access, functional monitoring equipment, and appropriate follow-up inspections would allow the Agency to establish a stronger evidentiary foundation than an isolated visit could ordinarily provide.

The October proposal may consequently have both diplomatic and technical value if implemented. Its significance under international law would depend on whether it facilitates the Agency's existing safeguards responsibilities or authorizes additional activities capable of addressing identified verification gaps. Neither the secrecy of the visit nor the political agreement surrounding it would determine the Agency's findings.

Conclusion

International nuclear safeguards law permits confidential inspections and authorizes certain unannounced inspection procedures under Iran's comprehensive safeguards agreement. Additional access may also be arranged under appropriate legal conditions. These possibilities remain governed by the Agency's mandate, the applicable safeguards provisions, and the technical requirements of independent verification.

The reported October 20, 2026 proposal has not been established as a completed safeguards inspection. Its legal character depends on the instrument under which the Agency would act, the locations involved, the procedures authorized, and the evidence inspectors could obtain. Confidentiality is compatible with lawful verification, but it cannot substitute for the information and access necessary to fulfill existing obligations.

Iran's outstanding safeguards deficiencies extend beyond the physical condition of its declared enrichment facilities. The Agency must address the status of previously declared enriched uranium, unresolved questions concerning undeclared material, and deficiencies in facility information and access. Separate obligations arising under relevant Security Council decisions add further requirements, notwithstanding the continuing dispute over the validity of their reapplication.

A confidential visit could contribute meaningfully to resolving particular questions and restoring nuclear monitoring. Its legal value would rest on the findings the IAEA can independently establish and the extent to which those findings address Iran's continuing obligations. Diplomatic cooperation may provide the conditions for verification, but compliance must ultimately be assessed through the safeguards system itself.

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