Israel Strikes Iran’s Nuclear Plant. Is it a Setback for Iran’s Nuke Ambitions?

The Israeli Air Force has bombed an unfinished heavy water reactor at Iran’s Arak nuclear site, which was long believed to have the potential to produce weapons-grade plutonium.

The details of the operation were released by the Israel Defense Forces.

On Thursday night, 40 Israeli fighter jets launched strikes on dozens of military targets in Tehran and other parts of Iran, deploying more than 100 munitions.

Among the main targets was the partially built Arak reactor, initially designed for plutonium production. Under international pressure, Iran had agreed to modify the reactor so that it could not be used for nuclear weapons purposes — but the redesign was never completed. According to Israeli officials, Iran used the facility as a bargaining chip in negotiations with Western countries.

The Israeli military said it had struck the reactor core to prevent it from being used in “nuclear weapons development.”

Footage released by the IDF shows bombs hitting the domed roof of the reactor building, along with several adjacent structures at the site, located about 250 kilometers southwest of Tehran.

Unfinished reactor, unresolved questions

Under the 2015 nuclear agreement, Iran committed to redesigning the Arak facility to reduce the risk of plutonium-based weapons development. The plan included pouring concrete into parts of the reactor, but the work was never fully completed.

The site became a renewed concern after the U.S. withdrew from the deal in 2018. Since then, Iran has restricted access to international inspectors. The International Atomic Energy Agency (IAEA) has said it no longer had full visibility into Iran’s nuclear activities or stockpiles of heavy water.

Heavy water, used as a coolant in certain types of reactors, allows for plutonium production as a by-product — a key element in nuclear weapon design. Several countries have historically used such reactors to produce plutonium for military use.

In parallel with the stalled Arak project, Iran has made significant advances in uranium enrichment. The IAEA’s most recent reports indicate that Iran now possesses a growing stockpile of uranium enriched to 60%.

IAEA Director General Rafael Grossi said two weeks before the latest hostilities that “Iran does not currently have a nuclear weapon, but it does have the material,” suggesting that weaponization could’ve happened quickly if Iran had chosen that path.

In 2023, Bloomberg reported that IAEA inspectors had detected traces of uranium enriched to 84%—just below the 90% threshold typically used in weapons-grade material, and far above the 5% level required for civilian nuclear power generation.