European powers threaten ‘snapback sanctions’ if Iran doesn’t return to nuclear talks

France, the U.K. and Germany have told the United Nations they support reinstating snapback sanctions on Iran, if it doesn’t re-enter dialogue with the West over its nuclear program, according to reporting by the Financial Times.

“We have made it clear that if Iran is not willing to reach a diplomatic solution before the end of August 2025, or does not seize the opportunity of an extension, E3 are prepared to trigger the snapback mechanism,” ministers of the three countries — using an acronym that describes the European signatories to the 2015 nuclear deal — said in a letter obtained by the FT.

The reported letter was delivered to the U.N. Security Council and U.N. Secretary-General António Guterres two months after Israel and the U.S. bombed Iran’s nuclear facilities over the course of a 12-day conflict that set regional tensions and energy prices soaring.

CNBC was not able to immediately verify the report and has contacted the Iranian foreign ministry and mission to the UN for comment.

‘Snapback’ sanctions are part of a mechanism that was built into the original 2015 Iranian nuclear deal — formally titled the Joint Comprehensive Plan of Action, or the JCPOA. The deal removed a number of sanctions on Iran in exchange for curbs to its nuclear program.

They were designed to act as a guardrail: if Iran commits a “significant non-performance” of the deal, any of the JCPOA signatory countries can trigger the automatic reimposition of U.N. sanctions lifted under the agreement, and no other permanent member can veto it.

The EU said in mid-July that it would start the process of reinstating UN sanctions on Tehran from Aug. 29 if it does not make sufficient progress on limiting its nuclear program. Those sanctions are set to expire on October 18 unless one of the remaining parties of the deal — Russia, China, or a member of the E3 — triggers the snapback option.

“‘Snapback’ looks set to be the word of the summer in European negotiations with Iran,” Ellie Geranmayeh, Deputy Director, Middle East and North Africa program at the European Council on Foreign Relations, wrote in a July report.

The consequences for Iran could be dire and could once more spike tensions and the possibility of conflict. Iranian officials have suggested the country could withdraw from the Nuclear Non-proliferation Treaty (NPT) if those sanctions are reimposed.

For its part, Tehran has said that it remains open to direct talks with the U.S. once more, but stopped short of accepting the terms to abandon its uranium enrichment program. The sixth round of talks with the U.S. was dropped after Israel and the U.S. began bombing Iran’s nuclear facilities in mid-June.

Iran’s economy has deteriorated dramatically in the years since Trump in 2018 withdrew the U.S. from the JCPOA.

Trump has made is abundantly clear that he will not accept a nuclear-armed Iran. The stakes have been raised in recent years: in the time since Trump withdrew from the deal, Iran has been enriching and stockpiling uranium at its highest levels ever, prompting the International Atomic Energy Agency, the United Nations’ nuclear watchdog, to issue numerous warnings. 

Tehran insists that its program is for civilian energy purposes only, but Iran’s nuclear enrichment has reached 60% purity, according to the IAEA — dramatically higher than the enrichment limit posited in the 2015 nuclear deal, and a short technical step from the weapons-grade purity level of 90%.