Europe’s Ultimatum to Iran: Nuclear Talks or Crippling Sanctions by August

Britain, France, and Germany, collectively known as the E3, have issued a stern warning to Iran, threatening to reinstate UN sanctions if it does not resume negotiations over its nuclear program by the end of August 2025. In a letter to the United Nations dated August 8, 2025, the E3 expressed readiness to activate the “snapback” mechanism, a provision of the 2015 Joint Comprehensive Plan of Action (JCPOA) that allows any signatory to reimpose sanctions if Iran violates its commitments. The letter, co-signed by French Foreign Minister Jean-Nöel Barrot, British Foreign Secretary David Lammy, and German Foreign Minister Johann Wadephul, was shared by Barrot on X on August 13, 2025. “E3 have always committed to use all diplomatic tools at our disposal to ensure Iran does not develop a nuclear weapon,” the letter stated. “We have made 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.”

The threat follows a diplomatic impasse exacerbated by a 12-day conflict in June 2025, during which Israeli and U.S. airstrikes targeted Iranian nuclear facilities, including sites at Fordo, Isfahan, and Natanz. Last month, E3 and Iranian officials met in Istanbul to discuss the potential reimposition of sanctions lifted in 2015 under the JCPOA, which curbed Iran’s nuclear activities in exchange for economic relief. Iran’s Foreign Ministry spokesman, Esmail Baghaei, expressed hope that the E3 would reconsider their “previous unconstructive attitude.” However, Iran has not commented on the latest development.

Since the June conflict, Iran has halted cooperation with the International Atomic Energy Agency (IAEA), suspending inspections after accusing the agency of bias. The IAEA’s recent visit to Iran on August 11, 2025, excluded nuclear sites, and full cooperation remains unrestored. German Foreign Ministry spokesperson Josef Hinterseher emphasized, “The letter once again underlines that the legal preconditions for snapback have long existed. Our position and our appeal is, very clearly, that Iran still has the choice of deciding to return to diplomacy … and full cooperation with the IAEA.”

Iran’s uranium enrichment to 60%, close to the 90% needed for weapons-grade material, has heightened concerns, despite U.S. and IAEA assessments that Iran’s organized nuclear weapons program ended in 2003. The E3’s letter noted Iran’s uranium stockpile exceeds JCPOA limits by over 40 times. Triggering the snapback could reinstate sanctions on arms, banking, and nuclear technology, but Iran resuming IAEA cooperation could delay this. With the JCPOA’s sunset clauses nearing expiration in October 2025, the E3 are exploring an extension to maintain leverage, as China and Russia, fellow signatories, may oppose new sanctions.