On September 28, 2025, the United Nations Security Council (UNSC) re-imposed previously lifted sanctions against Iran. The move occurred when the European powers triggered the “snapback” mechanism of the Joint Comprehensive Plan of Action (JCPOA) on August 28, 2025.
This marked the collapse of a decade-long diplomatic agreement that once promised to restrain Iran’s nuclear program in exchange for sanctions relief. The re-imposition of UN sanctions on Iran through the JCPOA snapback mechanism underscores not only Iran’s isolation, but also the failure of Western diplomacy. By abandoning reciprocity, relying on coercion, and aligning with Washington’s “maximum pressure” strategy, European powers not only eroded trust but also exposed their inability to sustain credible agreements, making sanctions a symbol of diplomatic defeat rather than success.
The roots of Iran’s sanctions regime date back to 2005 when the International Atomic Energy Agency (IAEA) declared Iran non-compliant with its safeguard obligations. In 2006, the UN Security Council unanimously approved sanctions restricting uranium enrichment materials, missile technology, and related financial transactions. Successive resolutions in 2007 and 2008 further tightened the restrictions. In 2010, sanctions were expanded to target Iran’s oil revenues and banking sector, linking them directly to proliferation concerns.
These sanctions were lifted under the JCPOA in 2015, an agreement between Iran and world powers. The agreement also included a snapback clause; if Iran violated its obligations, any party to the agreement can activate the snapback mechanism and re-impose sanctions before the expiration date of the JCPOA on October 18, 2025. On August 28, 2025, after repeatedly accusing Iran of non-compliance, the E3 (France, Germany, and the UK) activated the snapback mechanism that will re-impose UNSC sanctions on Iran after a 30-day time period.
The snapback that went into effect on September 28, 2025, reinstates UNSC sanctions, originally imposed 2006–2010. These sanctions include an arms embargo, ban on ballistic missile technology transfers, and restrictions on oil revenues and financial services—including Iran’s central bank. This decision aligns Europe more closely with the American position, despite Washington having withdrawn from the JCPOA in 2018. However, the sanctions are not binding on China and Russia, and both remain aligned with Iran and critical of the European move.
Iranian President Masoud Pezeshkian condemned the sanctions as “unfair, unjust, and illegal.” Tehran recalled its ambassadors from the United Kingdom, France, and Germany for consultations but clarified it had no immediate plans to withdraw from the Nuclear Non-Proliferation Treaty (NPT). Any further response, however, will likely be determined by the Iranian parliament.
The JCPOA was built on reciprocity and trust, but after the US withdrew, Europe failed to deliver promised economic benefits. Instead, Iran faced escalating accusations and even sabotage.
Coordinated attacks by the US and Israel in June 2025 on Iran’s nuclear facilities during negotiations eroded any remaining trust in Western intentions. Today, Iranian officials view Western diplomacy less as a pathway to compromise and more as a tool for coercion and deception.
While Russia and China echoed Iran’s position and warned that the European move would fuel further instability in the region, the E3 maintained that Iran’s nuclear activity crossed red lines. E3 members also emphasized that diplomacy was not over by offering to delay sanctions for six months if Iran restored access for inspectors and engaged in talks with the US.
The reactivation of sanctions primarily reflects Europe’s failure to secure diplomatic gains after the 12-day war earlier this year. Western powers assumed Iran’s weakened position, given that internal unrest, economic strain, and military pressure would push it toward compromise. Instead, Iran resisted demands for zero enrichment and even presented partial solutions at the UN, which were rejected. The E3’s alignment with Washington now resembles Trump’s “maximum pressure” strategy, raising the risk of further escalation rather than resolution.
Nevertheless, the first brunt of these sanctions will fall on ordinary Iranians. Currency devaluation, unemployment, and economic stagnation will intensify along with the hardships caused by protests and war. The Iranian banking sector, already fragile, faces further isolation. Yet for Iran’s leadership, these sanctions may not dramatically alter strategic calculations. Having endured American sanctions since 2018, Tehran has adapted by relying increasingly on its Look East strategy to deepen economic and diplomatic ties with China and Russia.
The energy sector will again come under strain, but much depends on how aggressively the US enforces secondary sanctions, particularly against China, one of Iran’s largest oil buyers. If oil exports continue through alternative routes, Iran will remain financially afloat, albeit constrained. Thus, the sanctions are more likely to weaken Iran internally while leaving its external policies largely intact.
Perhaps the most dangerous consequence of the snapback is the possibility of renewed Israeli strikes against Iran’s nuclear infrastructure. In June 2025, Israel used IAEA findings as justification for bombing Iranian facilities, sparking a costly 12-day conflict. Israel could again resume attack under the guise of re-imposition of UNSC sanctions.
The attacks stalled Iran’s nuclear program by roughly two years, thus dragging the US into a wider regional confrontation with little strategic gain. By contrast, the JCPOA achieved restrictions on Iran’s nuclear program without military confrontation and provided economic benefits and political openings for both sides. It shows that diplomacy slows proliferation more effectively and cheaply than war. Yet with sanctions restored, Israel may once again seek a military solution, raising the risk of escalation across the region.
The re-imposition of UN sanctions through the snapback mechanism signals both the collapse of trust in the JCPOA framework and the deepening rift between Iran and the West. For Iran, the sanctions reinforce the perception that Western promises are unreliable, and diplomacy is a trap.
For Europe, the move highlights its limited influence, as it increasingly gravitates toward Washington’s approach rather than pursuing independent solutions. Ultimately, sanctions will punish ordinary Iranians more than they will alter Tehran’s strategic direction. With China and Russia unlikely to comply, Iran’s external lifelines remain intact. What has been lost, however, is the fragile trust built over a decade of negotiations.
The JCPOA demonstrated that diplomacy could restrain Iran’s nuclear ambitions without war; the snapback demonstrates how easily that progress is undone. As tensions rise, the international community faces a choice, either double down on coercion or return to diplomacy. The lesson of the past decade is unmistakable: military and economic pressure may delay Iran’s nuclear program, but only diplomacy can stop it.
Sidra Shaukat is a Research Officer at SVI. Views expressed in this article are the author’s own.
