Reuters: Iran nuclear timeline unchanged despite strikes

U.S. intelligence assessments indicate that the time Iran would need to build a nuclear weapon remains largely unchanged since last summer, despite months of conflict and military strikes, three sources familiar with the matter revealed to Reuters. 

Analysts had previously estimated that a U.S.-Israeli attack pushed the timeline for Tehran’s potential nuclear breakout to up to a year. That estimate has held steady even after a two-month war launched by U.S. President Donald Trump, aimed in part at halting Iran’s nuclear ambitions.

The latest U.S. and Israeli campaign, which began on February 28, has primarily targeted conventional military infrastructure, although Israel has struck several key nuclear facilities. According to the sources, significantly impeding Iran’s nuclear programme would likely require eliminating or securing its remaining stockpile of highly enriched uranium (HEU).

The conflict has since stalled following an April 7 truce between Washington and Tehran to pursue negotiations. However, tensions remain elevated, particularly after Iran disrupted shipping through the Strait of Hormuz, affecting roughly 20% of global oil supplies and triggering a broader energy crisis.

U.S. Secretary of Defence Pete Hegseth has said Washington’s objective is to ensure Iran does not acquire a nuclear weapon through ongoing diplomacy.

Before the June conflict, U.S. intelligence agencies assessed that Iran could produce enough weapons-grade uranium and assemble a bomb within three to six months. Following U.S. strikes on the Natanz nuclear facility, Fordow nuclear facility, and Isfahan Nuclear Research Center, that estimate was extended to approximately nine months to a year.

While the strikes damaged or destroyed key enrichment sites, the International Atomic Energy Agency has been unable to verify the location of roughly 440 kilograms of uranium enriched to 60%. The agency believes about half may be stored in underground tunnels at Isfahan but has not confirmed this since inspections were halted.

The IAEA estimates that Iran’s total stockpile of highly enriched uranium could be sufficient for up to 10 nuclear weapons if further refined.

“While Operation Midnight Hammer obliterated Iran’s nuclear facilities, Operation Epic Fury built on this success by decimating Iran’s defense industrial base that they once leveraged as a protective shield around their pursuit of a nuclear weapon," said White House spokeswoman Olivia Wales, referring to the June operation and the latest war that began in February. "President Trump has long been clear that Iran can never have a nuclear weapon – and he does not bluff.”

The Office of the Director of National Intelligence did not respond to requests for comment.

U.S. officials continue to frame the elimination of Iran’s nuclear program as a central objective.

"Iran can never be allowed to obtain a nuclear weapon. That is the goal of this operation," Vice President JD Vance wrote on X on March 2.

Experts say the unchanged timeline reflects the focus of recent military operations. While Israel has targeted some nuclear-linked sites, U.S. strikes have largely concentrated on Iran’s conventional military capabilities and defense infrastructure.

Eric Brewer, a former U.S. intelligence analyst, said the findings were expected. "Iran still possesses all of its nuclear material, as far as we know," said Brewer. "That material is probably located in deeply buried underground sites where U.S. munitions can't penetrate."

Some analysts also point to the limited number of remaining high-value nuclear targets that can be safely destroyed following earlier strikes.

U.S. officials have considered more direct options, including ground operations to retrieve HEU believed to be stored at Isfahan. Tehran, however, continues to deny pursuing nuclear weapons, maintaining that its program is for peaceful purposes.

Assessing Iran’s nuclear capabilities remains complex. While U.S. intelligence agencies broadly agree on the country’s potential timeline, some variation in analysis persists.

Additional factors may also influence Iran’s capabilities. U.S. Secretary of State Marco Rubio has argued that strikes on Iranian air defenses have weakened Tehran’s ability to protect its nuclear infrastructure.

Meanwhile, Israeli operations targeting Iranian nuclear scientists may have had a longer-term impact.

"I think everyone agrees knowledge can't be bombed, but know-how certainly can be destroyed," said David Albright, a former U.N. nuclear inspector.

By Sabina Mammadli