Iran refuses to inspect key nuclear facilities: The Iranian nuclear crisis edges toward the brink of losing control.

On February 27, 2026, International Atomic Energy Agency (IAEA) Director General Rafael Grossi distributed a confidential report to member states of the Board of Governors. The report stated that since the 12-day war last June, Iran has no longer allowed inspectors access to key nuclear facilities that were bombed by Israel and the United States. This means the international community can no longer monitor the scale, composition, and specific locations of Iran's enriched uranium stockpiles. At the Isfahan Nuclear Technology Research Center, located approximately 350 kilometers southeast of Tehran, satellite imagery shows frequent vehicle activity at tunnel entrances, where Iran's most sensitive nuclear materials are believed to be stored. The failure of the verification mechanism is pushing the Middle East toward a critical point of nuclear crisis.

Check the nuclear ambiguity state under vacuum.

According to the International Atomic Energy Agency's report on February 27, Iran currently possesses 440.9 kilograms of enriched uranium with a purity of 60%. The threshold for weapons-grade enriched uranium is 90% purity, and the technical step from 60% to weapons-grade is not far. Grossi once told the Associated Press that these stockpiles are theoretically sufficient to produce up to 10 nuclear bombs. However, after the conflict in June 2025, the actual status of these highly enriched uranium stocks has become impossible to ascertain.

In a letter to the IAEA dated February 2, Iran stated that due to threats and acts of aggression, continuing normal safeguards measures is legally untenable and practically unfeasible. Consequently, except for the Karun power plant under construction, while inspectors can access facilities that have not been attacked, access to the three core sites of Fordow, Natanz, and Isfahan has been completely blocked. According to standard procedures, nuclear materials of such high concentration should be inspected once a month. Now, inspectors can only rely on commercial satellite imagery for remote observation. The report mentioned that at the Isfahan facility, they observed regular vehicle activity at the tunnel entrance leading to the storage of enriched uranium, and signs of activity were also noted at Natanz and Fordow. However, without access to these facilities, it is impossible to confirm the nature and purpose of the activities.

This verification vacuum creates a dangerous state of nuclear ambiguity. Iran insists that its nuclear program is entirely for peaceful purposes and denies seeking nuclear weapons. However, the substantial opacity makes it difficult for the outside world, especially Israel and the United States, to rule out the worst-case scenario. This information asymmetry is prone to triggering miscalculations. A European diplomat based in Vienna privately stated that the current situation is more dangerous than any period before the 2015 Iran nuclear deal was reached, because we have not only lost the data but also the channels to obtain it.

The Legacy of Geopolitical Games and Military Operations

The immediate trigger for the current deadlock was the brief conflict that erupted in June 2025. Israel and the United States launched coordinated strikes on Iran's nuclear facilities, targeting Fordow, Natanz, and Isfahan. Iran responded with missile attacks on U.S. bases in the Middle East. This conflict tore apart the fragile consensus achieved through previous diplomatic engagements, pushing both sides back onto a confrontational path.

The military operation has left a dual impact. For Iran, the attack on its facilities has provided a reason to suspend comprehensive cooperation with the International Atomic Energy Agency and strengthen the underground defenses of its nuclear installations. Tehran’s decision-makers, particularly Supreme Leader Khamenei and the Islamic Revolutionary Guard Corps, may view external attacks as an existential threat that must be countered by enhancing their own deterrent capabilities. For the United States and Israel, while the strikes have temporarily delayed Iran’s nuclear progress, they have also destroyed the already fragile verification infrastructure, making it extremely difficult to rebuild monitoring mechanisms through diplomatic means in the future.

The deeper reason lies in the collision of strategic logics among the parties involved. Iran views the development of nuclear capabilities as a cornerstone for regime security and regional influence, with its enriched uranium stockpile being its most critical strategic asset and bargaining chip. Washington and Tel Aviv, on the other hand, consider preventing Iran from acquiring nuclear weapons capability as an inviolable red line. The U.S.-Iran negotiations mediated by Oman in Geneva in February 2026, followed by the planned technical-level talks in Vienna, unfolded precisely against this backdrop of mutual distrust. The core disagreement in the negotiations remains unchanged: the United States demands that Iran cease uranium enrichment activities on its soil or surrender its stockpile of highly enriched uranium, while Iran refuses to comply. The breakdown of last year's talks and the outbreak of war have created a vicious cycle—diplomatic failure leads to military escalation, which in turn further poisons the diplomatic atmosphere.

Regional Security and the Impact on the Global Non-Proliferation System

The impact of the Iran nuclear verification crisis extends beyond the Persian Gulf. It has first intensified the arms race and security dilemma in the Middle East. Israel has identified Iran's nuclear issue as its top national security concern, and its stance on taking unilateral action when necessary has never changed. The large-scale fleet and aircraft formations assembled by the U.S. Navy in the Persian Gulf and surrounding waters serve both as a deterrent and as preparation for potential military options. Regional countries such as Saudi Arabia and the UAE, despite their tense relations with Iran, also worry about the regional turmoil that a new war could trigger. Any miscalculation or provocation from either side could ignite a new and larger-scale conflict.

Secondly, this poses a challenge to the global nuclear non-proliferation regime centered on the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and the International Atomic Energy Agency (IAEA) safeguards system. As a signatory to the NPT, Iran has a legal obligation to cooperate with the IAEA. Its continued refusal to provide necessary verification access, if not effectively corrected, will set a dangerous precedent and undermine the authority of the international nuclear safeguards system. Other countries with nuclear ambitions may perceive from this that it is possible to evade international oversight by creating faits accomplis and exploiting conflicts among major powers.

The IAEA Board of Governors will convene a meeting in Vienna next week, with the Iranian nuclear issue as the focal point of the agenda. In his report, Grossi emphasized that the lack of continuity in knowledge... must be addressed with the utmost urgency. However, where does the solution lie? Applying pressure through sanctions? The experience of the past two decades has shown that unilateral sanctions cannot force Iran to compromise on its core interests. Resuming comprehensive negotiations? The wounds of the 2025 war require time to heal, and domestic political factors in Tehran, Washington, and Jerusalem constrain the room for compromise among leaders. Maintaining the status quo? That would mean the continuation of nuclear ambiguity, with the risk of a crisis accumulating over time.

This crisis is a test of the political wisdom and decisiveness of the international community. In underground tunnels where satellite imagery cannot penetrate, the stockpile of enriched uranium may be changing. And at the negotiation table and in military command centers, time may be slipping away bit by bit.