This story was originally published Sept. 28, 2012:
UNITED NATIONS - Israeli Prime Minister Benjamin Netanyahu warned the United Nations that Iran's progress toward a nuclear bomb would be irreversible by next spring or summer, a more specific time frame than he had previously given in public, and demanded that world powers draw a "red line" to trigger military action if Tehran refuses to stop before then.
Holding up a crude drawing of a round bomb with a burning fuse, Netanyahu told the General Assembly he believes that at its current rate, Iran will have produced enough sufficiently enriched uranium by mid-2013 to allow it to start working on an atomic weapon within "a few months, possibly a few weeks."
He did not threaten to attack Iran, however, and said he was still working with the Obama administration to curb Tehran's nuclear development without going to war.
He emphasized Israel's close ties to the United States, in what appeared an attempt to ease concern about a rift between the allies over Iran's potential nuclear threat, even as he increased public pressure on Washington for a stepped-up effort.
In his 30-minute address, Netanyahu drew a bright red line through the drawing of the bomb to make his point that unless the world stopped it, Iran would become an existential threat to Israel and a terrorist threat to the world. He compared a nuclear-armed Iran to a nuclear-armed al-Qaeda.
"The relevant question is not when Iran will get the bomb," he said. "It is at what stage we can stop Iran from getting the bomb."
Netanyahu's warning came as the six world powers that have tried to negotiate limits on Iran's nuclear program conferred on the sidelines of the U.N. meeting. Three high-level meetings between those nations and Iranian negotiators this year failed to produce a breakthrough, but U.S. officials said progress was still possible.
"We have some reason to believe the [talks with Iran] will move to a point of seriousness," said a senior State Department official, declining to provide details.
Asked for their reaction to Netanyahu's speech, the official said the six countries - the United States, Britain, France, China, Russia, and Germany - agreed that "diplomacy is the preferred path."
Iran says it is enriching uranium for energy generation and other peaceful uses, and that it is not seeking to build a weapon.
Iranian President Mahmoud Ahmadinejad, who addressed the General Assembly on Wednesday, said this week that his country did not rule out a negotiated solution to the standoff.
Netanyahu has pushed the White House for months to declare a "red line" beyond which Iran would risk military attack. He has not previously given as specific a deadline, although he has implied that the decision must be made before Iran has enough fissile material for a bomb.
"I believe that faced with a clear red line, Iran will back down," he said.
Analysts say his prediction appears to be based on calculations by the U.N. nuclear watchdog agency, the International Atomic Energy Agency, that Iran will have enough nuclear material for one bomb next year if it continues enriching uranium at the current rate.
When President Obama addressed the General Assembly on Tuesday, he repeated his position that the United States would not allow Iran to build a bomb, but he did not specify how far it could go. He said he hoped diplomacy and punitive economic sanctions would persuade Tehran to abandon its efforts, but warned that time was not "unlimited."
U.S. officials argue that setting a deadline or specifying what Iranian nuclear activity would trigger a U.S. attack would limit presidential options and could lead to an unnecessary war. Netanyahu's warning Thursday did not persuade the White House to change its view.
U.S. military and intelligence officials say they believe they will have some warning of any decision by Iranian leaders to build a bomb. Tehran would need to reconfigure its fast-spinning centrifuges to obtain the higher enrichment of uranium needed for a nuclear bomb, and it presumably would expel U.N. nuclear inspectors who regularly visit the facilities.