EXPLAINED: UNSC decides not to lift sanctions on Iran. What does it mean for Tehran's nuclear programme?

An attempt to block the return of the snapback mechanism against Iran, which France, Germany and the United Kingdom triggered in late August, collapsed at the Security Council yesterday, despite weeks of diplomatic parleys to reach a consensus. The measures will now be fully in force by the end of the month, restoring the sanctions regime that existed before the Joint Comprehensive Plan of Action (JCPOA).

Only China, Russia, Pakistan and Algeria backed the proposal put forth by South Korea, the council president. Nine members–the United States, Britain, France, Sierra Leone, Slovenia, Denmark, Greece, Panama and Somalia–voted against the motion. Guyana and South Korea abstained. The outcome sealed the diplomatic breakdown, confirming that the Europeans, despite years of delicate mediation, have chosen to confront Iran over its nuclear programme.

For months, the European powers have accused Iran of systematically breaching the JCPOA. Inspectors from the International Atomic Energy Agency (IAEA) reported in June that Tehran’s stockpile of enriched uranium exceeded the agreement’s limit by more than 40 times. The agency also concluded that Iran was not meeting wider international safeguards. French President Emmanuel Macron stated that Tehran’s attempts to avoid the snapback were not serious, and European officials argued that they could no longer ignore such violations.

The sanctions being restored will replicate those in place before 2015. They cover restrictions on ballistic missile development, a ban on conventional arms transfers, freezes on Iranian financial assets abroad and limitations on nuclear-related technology. Although Iran has already been hit hard by years of American “maximum pressure”, the return of UN measures adds legitimacy to Washington’s approach and underlines Iran’s deepening isolation.

Russia and China denounced the decision, accusing the Europeans of using the Security Council as a political weapon and destroying nearly a decade of painstaking diplomacy. Moscow described the move as a bad-faith play, while Beijing insisted that sanctions would not resolve the nuclear issue. For both, the vote reflected Europe’s alignment with Washington after years of attempting to maintain strategic distance.

Iran itself reacted angrily. Officials called the snapback unjustified, illegal and without legal basis, and branded it a direct assault on international law. Amir Saeid Iravani, Iran’s ambassador to the UN, accused the Europeans of abusing the JCPOA mechanism and pursuing politically motivated goals. “Today’s action is hasty, unnecessary and unlawful. Iran recognises no obligation to implement it,” said Iravani. “Any attempt by the E3 to reimpose sanctions already terminated is not only baseless but a direct assault on international law and the credibility of the Security Council itself.”

Tehran maintains that it upheld its commitments until 2018, when US President Donald Trump unilaterally pulled out of the deal and reimposed sanctions. Iranian leaders now warn that they may be forced to withdraw from the Nuclear Non-Proliferation Treaty altogether, a step that would echo North Korea’s move in 2003 and could pave the way for nuclear weapons development.

The implementation of the snapback mechanism should be seen against the backdrop of the conflict in June, when Israel, supported by the United States, launched a twelve-day offensive against Iran. Air strikes destroyed or damaged several nuclear facilities and weakened Iranian air defences.

At the IAEA’s General Conference soon after, Iran, backed by Russia and China, introduced a resolution condemning what it described as deliberate and unlawful attacks on its nuclear sites. The text was withdrawn after intense US lobbying, with Washington warning that funding for the agency could be reduced if measures seen as hostile to Israel were adopted. American officials defended the strikes as decisive action ordered by President Trump to counter the growing nuclear threat.

Despite the hostile exchanges, Britain insisted that the door to diplomacy remained open. The Europeans had earlier offered to postpone the snapback for six months if Iran granted full inspector access and engaged in direct talks with Washington. Yet the EU’s foreign policy chief, Kaja Kallas, has admitted that the opportunity for a negotiated solution is closing quickly.

The sanctions may not inflict much additional economic pain beyond what Iran already suffers under US measures. The political consequences, however, are expected to be severe, pushing any new agreement further out of reach. Experts caution against assuming that the June air strikes have ended the nuclear threat, pointing out that Iran retains the capacity to rebuild its programme. The risk, they argue, is of sliding into a cycle of repeated military action, a “forever war” that fails to deliver lasting security.