Key facts
- The U.S. and Israel launched a war against Iran with the objective of preventing nuclear weapon development.
- Iran's nuclear program involves uranium enrichment, a process to increase the concentration of U-235.
- Iran possesses an estimated 972 pounds (441 kilograms) of uranium enriched to 60% purity.
- Uranium enriched above 90% is considered weapons-grade.
- Iran is not in compliance with the Treaty on the Non-Proliferation of Nuclear Weapons.
- The IAEA cannot verify Iran's nuclear activities due to lack of access to bombed facilities.
The ongoing war initiated by the U.S. and Israel against Iran has intensified scrutiny on Tehran's nuclear program, particularly its uranium enrichment activities. President Donald Trump stated that a primary objective of the conflict is to prevent Iran from developing nuclear weapons.
Uranium enrichment is a process crucial for both nuclear power generation and the creation of nuclear weapons. Natural uranium contains less than 1% of the fissile isotope U-235, with the remainder being the more stable U-238. Enrichment aims to increase the concentration of U-235 by separating it from U-238, typically using centrifuges.
Different levels of enrichment serve different purposes. Uranium enriched up to 5% is suitable for nuclear reactors generating electricity, while enrichment up to 20% is used for scientific experiments. Uranium enriched above 20% is considered highly enriched, and levels above 90% are classified as weapons-grade. However, some highly enriched uranium can be used for research and medical applications.
According to the International Atomic Energy Agency (IAEA), Iran possesses an estimated 972 pounds (441 kilograms) of uranium enriched to 60% purity. Experts suggest that uranium at this level is a short, technical step away from weapons-grade material, and it can be relatively easily enriched further to the 90% threshold required for a bomb. The IAEA has previously indicated that Iran's stockpile could potentially allow for the construction of multiple nuclear bombs, though it does not possess such a weapon.
Once enriched, uranium gas is processed into pellets and used as fuel rods in nuclear reactors or can be converted for use in nuclear weapons. The weaponization process is complex, requiring miniaturization of the warhead for missile delivery.
Iran is a signatory to the Treaty on the Non-Proliferation of Nuclear Weapons, which mandates peaceful use of nuclear material for non-nuclear states and disarmament for nuclear states, with IAEA inspections to ensure compliance. Iran was found to be in non-compliance in the early 2000s due to a secret weapons program and again in June 2025 for failing to provide credible explanations for uranium particles found at undeclared sites.
Recent reports indicate that Iran has denied the IAEA access to its nuclear facilities that were bombed during the recent conflict. Consequently, the IAEA cannot verify whether Iran has halted all enrichment-related activities or ascertain the size of its uranium stockpile at the affected sites.