The Joint Comprehensive Plan of Action (JCPOA), commonly known as the Iran nuclear deal, is a landmark international agreement reached on July 14, 2015, between Iran and the P5+1 group (China, France, Russia, the United Kingdom, the United States, and Germany), along with the European Union. The accord was designed to curb Iran's nuclear program to ensure it remains exclusively peaceful, in exchange for lifting nuclear-related economic sanctions imposed by the UN, EU, and United States. Key provisions included reducing Iran's operational centrifuges by two-thirds, limiting uranium enrichment to 3.67% for 15 years, capping the low-enriched uranium stockpile at 300 kg, and redesigning the Arak heavy-water reactor to prevent plutonium production. Iran also agreed to enhanced IAEA monitoring and verification measures, including continuous surveillance at nuclear facilities. The deal was endorsed by UN Security Council Resolution 2231, marking a shift from confrontation to diplomacy after over a decade of tensions.

Implementation began in January 2016, with Iran complying initially and receiving sanctions relief that boosted its economy through oil exports and trade. However, the agreement faced significant challenges, including the U.S. withdrawal in May 2018 under President Donald Trump, who criticized it as flawed for not addressing Iran's ballistic missile program or regional activities. This led to the reimposition of U.S. sanctions, prompting Iran to incrementally breach JCPOA limits starting in 2019, such as exceeding uranium stockpiles and enrichment levels. Revival talks, mediated by the EU and involving indirect U.S.-Iran negotiations in Vienna from 2021 onward, have stalled amid disputes over sanctions relief, Iran's nuclear advances, and geopolitical tensions. Many core restrictions are set to expire after 10-15 years, with the 'snapback' mechanism allowing sanctions reinstatement until 2025. The JCPOA remains a pivotal, though fragile, framework for non-proliferation, influencing global influence networks in Middle East policy and U.S.-Iran relations.