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The E3’s letter, reported by AFP, emphasizes their commitment to preventing Iran from developing nuclear weapons, stating, “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.” The snapback mechanism, embedded in the 2015 Joint Comprehensive Plan of Action (JCPOA), allows signatories to restore UN sanctions if Iran violates the agreement’s terms.
The JCPOA, signed by Iran, the E3, the United States, China, Russia, and the European Union, aimed to curb Iran’s nuclear programme in exchange for sanctions relief. However, the deal has been under strain since 2018, when then-US President Donald Trump withdrew the United States and reimposed sanctions. The E3 claims Iran has since violated the agreement, amassing a uranium stockpile over 40 times the permitted limit, though no evidence suggests enrichment to weapons-grade levels of 90 percent.
Tensions escalated further in June 2025, when Israel launched a 12-day military campaign targeting Iranian nuclear facilities, senior military leaders, and scientists. The United States also conducted airstrikes on Iran’s nuclear sites, prompting Tehran to suspend cooperation with the International Atomic Energy Agency (IAEA). Despite this, Iran has recently agreed to resume talks with the IAEA, with a visit from the UN nuclear watchdog expected soon—the first since the June conflict.
The E3’s warning follows “serious, frank, and detailed” discussions with Iran in Istanbul last month, the first in-person talks since the Israeli and US strikes. Iran insists its nuclear programme is for civilian purposes and denies pursuing nuclear weapons. Iranian Foreign Minister Abbas Araghchi has argued that the E3 lacks the legal or moral grounds to trigger snapback sanctions, warning that such a move could end Europe’s role in future nuclear talks.
The JCPOA’s dispute resolution mechanism, set to expire in October 2025, allows any signatory to reinstate sanctions without a new UN Security Council vote, bypassing potential vetoes from Russia or China. If triggered, snapback would restore pre-2015 sanctions, including arms embargoes, financial restrictions, and bans on nuclear technology transfers, binding all UN member states under international law.
As the deadline looms, the E3’s threat underscores the fragile state of the Iran nuclear deal and the broader geopolitical tensions in the region, with the risk of further escalation if diplomacy fails.
