When did Iran’sactions raise significant international concerns regarding nuclear proliferation?

Iran's actions raised significant international concerns regarding nuclear proliferation most notably around 2020. While concerns existed earlier, particularly after the US withdrew from the Joint Comprehensive Plan of Action (JCPOA) in 2018, Iran began to significantly exceed the enrichment limits set by the deal in 2019 and 2020. This escalation, including increasing uranium enrichment levels and stockpiles, intensified international alarm and led to heightened scrutiny from the IAEA and global powers.

• 2015 was when the JCPOA was signed, which temporarily eased proliferation concerns.
• 2018 saw the US withdrawal from the deal, but Iran's most concerning actions in response intensified in the subsequent years.
• 2022 saw continued concerns, but 2020 marked a critical period of Iran's escalating nuclear activities post-JCPOA.