The International Atomic Energy Agency (IAEA) is the United Nations body responsible for verifying that the civil nuclear programs of states do not deviate towards military purposes. Its function focuses primarily on the control of sensitive nuclear material, and especially on the uranium enrichment process, a dual-use technology that can serve both to produce civil fuel and, from certain levels, to manufacture nuclear weapons.
The IAEA’s ability to oversee this process — knowing how much uranium is enriched, to what degree, where, and with what continuity — constitutes one of the technical pillars on which non-proliferation diplomacy rests.
In the case of Iran, this function gained exceptional relevance after the 2015 nuclear agreement. During the years it was operational, the IAEA deployed the most intrusive verification system ever applied to a non-nuclear state, combining permanent inspectors, expanded access to facilities, control of key workshops, and an extensive network of cameras and sensors. This framework allowed not only to verify current activities but also to reliably reconstruct the complete history of Iranian nuclear material.
That system began to be dismantled in February 2021, when Iran stopped applying the Additional Protocol — the legal instrument that allows the IAEA to access facilities, data, and undeclared activities with expanded scope — and suspended much of the enhanced verification measures associated with the agreement. The withdrawal of cameras, the disconnection of surveillance equipment, and the loss of access to certain points in the fuel cycle broke a chain that cannot be reconstructed retrospectively. Even if access were to be restored immediately, there would be an opaque period impossible to audit with certainty.
The situation was decisively aggravated after the attacks on Iranian nuclear facilities in June 2025 by Israel and the United States and the subsequent decision by Tehran to almost completely suspend cooperation with the IAEA, citing security reasons. Since then, inspectors have not had substantive access to the main enrichment facilities, such as Natanz, Fordow, or Isfahan. The agency itself acknowledges that it cannot verify either the continuity of activities or the location of the stock of uranium enriched to 60%, a level technically very close to military grade.
The problem is not limited to the specific deterioration of access. Analyses from the Stockholm International Peace Research Institute (SIPRI) and the International Institute for Strategic Studies (IISS) emphasize that Iran has accumulated significant amounts of uranium enriched to 60% in recent years, a level that does not correspond to known civil needs and objectively reduces the available reaction times. From a technical standpoint, once that level of enrichment is reached, the leap to military grade requires relatively reduced additional effort, because the longer, more complex, and demanding phases of the uranium separation process have already been completed.
Achieving mastery of all phases of the nuclear cycle has required Iran a sustained investment over several decades in infrastructure, training of highly specialized personnel, and accumulation of its own scientific and industrial knowledge. This situation contrasts with that of other states, which generate less international alarm because they do not master the entire nuclear fuel cycle or maintain continuous and verifiable cooperation with the IAEA. In these cases, the fact of not autonomously controlling the most sensitive phases — particularly enrichment — implies dependence on external suppliers to obtain already processed fuel and operate under stable supervision mechanisms, significantly reducing the margins of uncertainty.
Documents from the European Parliament and national parliaments warn that, when verification is consistently weakened, preventive dynamics foreseen in previous sanctions regimes tend to be activated, even in the absence of demonstrated violations. The loss of shared information reduces the space for engagement and shifts the weight of decision-making towards worst-case scenarios.
Sources: International Atomic Energy Agency, especially the reports of the Director General to the Board of Governors on Verification and monitoring in the Islamic Republic of Iran in light of United Nations Security Council Resolution 2231 (2015) corresponding to 2024, 2025, and 2026, which document the loss of continuity of knowledge, the suspension of the Additional Protocol, and the impossibility of verifying the stock of uranium enriched to 60%; Stockholm International Peace Research Institute (SIPRI) and International Institute for Strategic Studies (IISS), particularly their technical analyses on the strategic significance of 60% enrichment, the non-linearity of the separation work, and the reduction of reaction times; Institute for Science and International Security (ISIS), in its periodic assessments of the IAEA reports on Iran, widely used as a technical reference by governments and international organizations; Statements and documents from the European External Action Service, the European Parliament, and the E3 (France, Germany, and the United Kingdom) before the IAEA Board of Governors, which support the institutional reading on the political consequences of the erosion of verification; Coverage by international agencies such as Associated Press and PBS NewsHour based on confidential IAEA reports, which publicly confirms the current limitations of oversight.