VIENNA, Austria — The U.N. atomic agency has received new and significant intelligence over the past month that Iran has moved further toward the ability to build a nuclear weapon, diplomats tell the Associated Press.
They say the intelligence shows that Iran has advanced its work on calculating the destructive power of an atomic warhead through a series of computer models that it ran sometime within the past three years.
The diplomats say the information comes from Israel, the United States and at least two other Western countries and concludes that the work was done sometime within the past three years.
The time frame is significant because if the International Atomic Energy Agency (IAEA) decides that the intelligence is credible, it would strengthen its concerns that Iran has continued weapons work into the recent past — and may be continuing to do so.
Because computer modeling work is normally accompanied by physical tests of the components that go into a nuclear weapons, it also would buttress IAEA fears outlined in detail in November that Tehran is advancing its weapons research on multiple fronts.
“You want to have a theoretical understanding of the working of a nuclear weapon that is then related to the experiments you do on the various components,” said David Albright, whose Washington-based Institute for Science and International Security is a frequent go-to source on Iran for Congress and other U.S. government branches. “The two go hand-in-hand.”
Such computer mock-ups typically assess how high explosives compress fissile warhead material, setting off the chain reaction that results in a nuclear explosion. The yield is normally calculated in kilotons.
Any new evidence of Iranian research into nuclear weapons is likely to strengthen the hand of hawks in Israel who advocate a military strike on Iran. They argue that Tehran is deliberately stalemating international efforts at engagement while continuing its clandestine weapons work.
Iran denies any interest in nuclear weapons, and says suspicions that it ever tried to develop them are based on fabricated U.S., Israeli and other intelligence. At the same time, it has blunted IAEA efforts to investigate such claims for more than five years.
It also has scoffed at Western allegations that it is enriching uranium to make the core of nuclear warheads, saying it seeks only to create reactor fuel.
But it refuses to accept offers of such fuel from abroad and now is producing material that is easier to turn into weapons-grade uranium than its main, lower-enriched stockpile.
The revelations come as Israeli officials are expressing growing alarm over what they see as continuing Iranian progress toward nuclear arms.
Israeli Prime Minister Benjamin Netanyahu engaged this week in a strident public exchange with the U.S. administration, calling on Sunday for “red lines” to be set for Iran.
The calls were rebuffed, and on Tuesday, Mr. Netanyahu declared that “those in the international community who refuse to draw a red line on Iran don’t have a moral right to place a red light before Israel.”
Mr. Netanyahu said that sanctions are hurting Iran’s economy but not nearly enough to compel it to stop the nuclear program, and said negotiations by the international community with Iran on the issue had failed.