Diplomatic tensions between Iran and European powers have reached a critical juncture, with the threat of United Nations sanctions looming over Tehran’s nuclear program. On September 17, 2025, Iranian Foreign Minister Abbas Araqchi held a high-stakes phone call with his counterparts from Britain, France, and Germany—the so-called E3—alongside European Union foreign policy chief Kaja Kallas. Their urgent agenda: to discuss the possible reimposition of international sanctions and explore any last-minute avenues to delay such a move.
This flurry of diplomacy comes after the E3 triggered a one-month process in late August that could restore UN sanctions previously lifted under the 2015 nuclear deal. That landmark agreement, which once promised a new era of cooperation, has been unraveling ever since the United States withdrew in 2018. Now, with the clock ticking down, the risk of a snapback—a mechanism that automatically reinstates sanctions if Iran is found out of compliance—has never felt more real.
For Iran, the stakes are enormous. The potential sanctions would hit core sectors of its economy: financial, banking, hydrocarbons, and defense. According to Reuters, several European diplomats and an Iranian official suggested before the September 17 call that the most likely scenario is the E3 moving ahead with the reimposition of sanctions. An Iranian diplomat was blunt about Tehran’s expectations, stating, “The understanding in Tehran is that the U.N. sanctions will be reimposed. That is why Tehran refuses to give concessions.”
But what exactly stands in the way of a diplomatic breakthrough? The E3 has set clear conditions for Iran to meet during September if it hopes to avoid renewed sanctions. Chief among them is the restoration of access for UN nuclear inspectors—specifically, the International Atomic Energy Agency (IAEA)—to Iranian nuclear sites. The E3 also wants Iran to engage in talks with the United States, a step that remains politically sensitive in Tehran.
The urgency of the situation was only heightened by recent history. In June 2025, Israeli and U.S. forces bombed Iranian nuclear facilities, plunging the status of Iran’s enriched uranium stocks into uncertainty. Since then, months of disruption and heightened security concerns have made cooperation with international inspectors even more fraught. According to BBC, one key condition for postponing sanctions has been renewed cooperation between Iran and the IAEA.
In a glimmer of hope, Tehran did reach an agreement with the UN nuclear watchdog last week to resume collaboration, including inspections of nuclear sites. This step was widely seen as a positive move, at least on paper, and formed the backdrop for the September 17 call. Yet several Western diplomats quickly poured cold water on the optimism, criticizing the accord as too vague, with no clear timeframe and plenty of room for Iran to continue stonewalling. As one Western official told Reuters, “The accord is not detailed enough, sets no timeframe, and leaves the door open for Iran to continue stonewalling.”
Germany’s foreign ministry didn’t mince words, either. In a statement posted on X (formerly Twitter), the ministry said the E3 had “underscored that Iran has yet to take the reasonable and precise actions necessary to reach an extension of Resolution 2231,” warning that sanctions would be reimposed unless there were “concrete actions in the coming days.” The message was clear: the window for diplomacy is rapidly closing.
Iran, for its part, has tried to project both resolve and a willingness to talk. In the September 17 call, Foreign Minister Araqchi expressed a desire for a “fair and balanced” solution, according to Iranian state media. In his words: “The Islamic Republic of Iran has entered into dialogue with the International Atomic Energy Agency with a responsible approach ... on how Iran will fulfil its safeguards obligations in the new situation ... It is now the turn of the opposing parties to use this opportunity to continue the diplomatic path and prevent an avoidable crisis.”
Yet beneath the surface, there’s a palpable sense of frustration on both sides. Iran insists that its nuclear program is solely for peaceful energy purposes, repeatedly denying any ambition to develop nuclear weapons. Tehran’s officials have urged the E3 to respond with a “positive approach and goodwill” if they wish to avoid an escalation, emphasizing that perpetuating current tensions serves no one’s interests. As Foreign Ministry spokesperson Esmaeil Baghaei put it, undermining the IAEA process “would be a sign of rejection of the agency itself.”
On the other hand, Western governments remain deeply skeptical. The United States and its allies argue that Iran’s nuclear program has advanced far beyond what’s needed for civilian energy, pointing to its growing stockpiles of enriched uranium. The lack of transparency since the June bombings has only fueled suspicions. Several diplomats told Reuters that there’s been no indication of Iran’s willingness to resume talks with Washington, a key demand from the E3.
The stakes are more than just diplomatic. If sanctions return, Iran’s already struggling economy could face even greater hardship. The sanctions regime would target vital sectors, potentially choking off revenues and further isolating Tehran. Iranian officials have warned that they will retaliate if the decision to restore UN sanctions is made, though the specifics of any response remain unclear.
Meanwhile, the broader international community is watching closely. The 2015 nuclear deal—formally known as the Joint Comprehensive Plan of Action—was once hailed as a triumph of multilateral diplomacy. Its unraveling could have ripple effects far beyond Iran’s borders, raising concerns about nuclear proliferation and regional security. European leaders, while frustrated with Tehran’s lack of concessions, are also wary of a full-blown crisis that could destabilize the Middle East even further.
For now, the ball appears to be in Iran’s court. The E3 has offered to put off the snapback for up to six months to enable serious negotiations, but only if Tehran restores access for UN inspectors and engages in substantive talks. Iran, meanwhile, is “refining how it will work with the IAEA” and insists it has done its part by resuming cooperation. The coming days will determine whether this fragile diplomatic dance leads to a breakthrough—or a breakdown.
As the deadline approaches, all eyes are on Tehran and the European capitals. Will dialogue prevail, or are new sanctions inevitable? The answer could shape not only the future of Iran’s nuclear program, but the stability of the region for years to come.