Iran's Nuclear Enrichment Progress

Iran expanded its nuclear enrichment program from the late 1990s through June 2025, when U.S. and Israeli strikes, and additional strikes from February to April 2026, destroyed most of Tehran’s nuclear assets.

Prior to this, Iran’s enriched uranium stockpiles and centrifuge infrastructure grew dramatically across successive American administrations, beginning under President George W. Bush, and surviving periods of diplomacy, including President Barack Obama’s 2015 nuclear deal known as the Joint Comprehensive Plan of Action (JCPOA). During his first term, President Donald Trump removed the United States from the deal, which permitted a massive future expansion of the program. Under President Joe Biden, Iran massively expanded advanced centrifuge deployments and pushed enrichment to near-weapons-grade levels. The chart below tracks Iran’s steady accumulation of these stockpiles, and includes an alternate future had Trump not withdrawn from the JCPOA, which permitted massive growth of Iran’s enrichment capabilities.

The strikes have done more to set back Iran’s nuclear threat than diplomacy ever did — at least temporarily nullifying the threat of a near-term nuclear breakout. Any negotiated agreement must therefore consider a new reality: for the first time since 2006, Iran is no longer enriching uranium and has no operating enrichment plants. The United States should insist that Iran is never permitted to restart, and correspondingly, demand the full, verified dismantlement of all enrichment infrastructure.