Iran warned on 14 July that it would deliver an “appropriate and proportionate” response if Britain, France and Germany invoked the United Nations “snapback” mechanism to restore sanctions lifted under the 2015 nuclear accord. Foreign-ministry spokesperson Esmaeil Baghaei said the European powers lacked the legal and moral standing to take such a step, calling the threat politically motivated and illegitimate. The warning framed a fresh round of nuclear diplomacy on 25 July, when Deputy Foreign Minister Kazem Gharibabadi met E3 negotiators in Istanbul. Both sides described the session as serious, frank and detailed, and agreed to continue talks. A European diplomatic readout said there was neither a breakthrough nor a breakdown, with the E3 reiterating readiness to trigger snapback while offering room for diplomacy if Tehran curbs its nuclear activity. Under the JCPOA, any participant can reimpose multilateral sanctions if it judges Iran to be in significant non-compliance. The Europeans say Tehran’s continued enrichment of uranium to 60 percent—far above the 3.67 percent cap in the deal—could force their hand before key provisions expire in October. Iran maintains that it remains a party to the accord and blames the West for earlier breaches after the United States quit the pact in 2018. A revival of UN restrictions would tighten pressure on an economy already hit by U.S. penalties. Iran’s sharp rhetoric coupled with its decision to keep talking suggests both Tehran and the Europeans are testing whether a negotiated compromise is still possible ahead of the looming deadline.