When the prime minister of Israel, Benjamin Netanyahu, drew his red line on a cartoonish diagram of a bomb from the podium of the United Nations General Assembly on Thursday, his intention was to keep it simple and illustrate in easy terms to the world the point at which Iran’s uranium enrichment program must be stopped to prevent Tehran from making the final sprint to build a nuclear weapon.

Instead, the attention-grabbing performance seems to have led to some confusion in, of all places, Israel.

Mr. Netanyahu’s bomb was divided into sections marked 70 percent and 90 percent, representing the amount of progress Iran has made, or will make, toward amassing enough enriched uranium for a bomb, Israeli officials and experts said.

Mr. Netanyahu drew his red line at the 90 percent mark, suggesting that the Iranians would be 90 percent along the way - a point he asserted they will reach by next spring, or summer at the latest.

But on Friday, Israel’s leading weekend paper, Yediot Aharonot, interpreted the diagram differently, assuming that Mr. Netanyahu was referring not to progress made, but to actual percentages of uranium enrichment.

Iran has a stockpile of medium-enriched uranium - uranium enriched to the level of 20 percent. To build a bomb, it would have to convert its uranium to weapons-grade fuel of a much higher purity, enriched to a level above 90 percent, though Iran insists that its nuclear program is for purely civilian purposes.

“On the assumption that we are talking about enrichment percentages, the Iranians have by now reached levels somewhere between 3.5 percent and 20 percent today,” Nahum Barnea, a leading columnist, wrote on the front page of the newspaper in a piece titled “Bibi Boom,” addressing an Israeli public relatively well-versed in the technicalities. “Netanyahu said last night that they had reached 70 percent, a considerable leap. It seems to me that he is the first one in the world to name such a number.”

“Netanyahu draws his red line at a 90 percent level. This level is very close, perhaps too close, to a level that enables the production of a bomb,” Mr. Barnea continued.

Ronen Bergman, the newspaper’s resident expert, also explained Mr. Netanyahu’s red line in terms of percentages of enrichment in an article accompanied by a graphic to clarify the various stages.

Mr. Barnea said by telephone that the paper had based its analysis in part on what they were told by Israeli officials, but added, “It doesn’t make sense; the numbers are not clear.”

Dore Gold, president of the Jerusalem Center for Public Affairs and an adviser to Mr. Netanyahu during his first term as prime minister in the 1990s, said that interpreting the diagram in terms of levels of enrichment was mistaken.

“Netanyahu cannot draw a line at 90 percent enrichment,” Mr. Gold said. “If you get to 90 percent enrichment, the whole of the West is in big trouble.”

“As soon as I saw the bomb I understood what Netanyahu was getting at, because if you deal with percentages of enrichment, you leave people behind,” Mr. Gold added.

Mr. Netanyahu’s aides declined to reveal who on the prime minister’s staff had drawn the bomb, saying it would not be appropriate. But a member of the Israeli delegation to the General Assembly said the diagram had been effective in “augmenting the prime minister’s verbal policy message” in a setting notorious for long speeches.

Mr. Netanyahu has frequently drawn a similar diagram during meetings with visiting diplomats or members of Congress, according to an official who has sat in on the sessions. “That’s something he’s had in his head for a long time,” the official said on the condition of anonymity because he was not authorized to discuss the sessions. Never before, though, had the official seen Mr. Netanyahu actually take out a marker and draw a red line across the diagram.

The episode left many Israelis wondering.

“Bibi is not an expert on uranium enrichment, and neither am I, so I’ll be careful,” said Shlomo Avineri, a professor of political science at the Hebrew University of Jerusalem, immediately after the speech, referring to the prime minister by his nickname. “But it is not very clear where the red line is.”

Martin Indyk, a former United States ambassador to Israel who is now vice president and director of the Foreign Policy Program at the Brookings Institution, said that “the problem with the whole red line issue is that Israel has set so many red lines and the Iranians have crossed every one of them.”

In the middle of an American presidential campaign and with the American people tired of wars in the Middle East, “the notion that this is actually going to produce a red line is unrealistic,” he said of Mr. Netanyahu’s performance.

Mr. Indyk said he understood that Mr. Netanyahu wanted to draw a line on any Iranian attempt to break out and enrich uranium beyond the 20 percent level, “though that’s not clear from what he drew,” Mr. Indyk added.

Another criticism of Mr. Netanyahu’s speech was more predictable. An Iranian official took a jab both at Mr. Netanyahu’s speech and former Secretary of State Colin Powell’s ultimately flawed contention before the United Nations in 2003 that Iraq had weapons of mass destruction.

“For the second time in the recent history of the United Nations, today an unfounded and imaginary graph was used to justify a threat against a founding member of the United Nations,” Iran’s deputy ambassador, Eshaq al-e-Habib, said in a statement. “However, it is worth mentioning that in our increasingly interconnected world and in the information age, it is hardly possible for the nations to be fooled by such absurd means.”

Rick Gladstone contributed reporting from New York, and Jodi Rudoren from Jerusalem.

Netanyahu’s Bomb Diagram Stirs Confusion In Israel

meanwhile …. putting to one side Julia Gillard’s equally deceitful performance ….

Iran said Friday that Israel’s latest warnings at the United Nations of an impending Iranian atomic weapons threat were baseless theatrics, and called on Israel to disband its own unacknowledged nuclear weapons arsenal and sign the Non-Proliferation Treaty just as Iran had done 44 years ago.

The Iranians were responding to the General Assembly speech on Thursday by Prime Minister Benjamin Netanyahu of Israel, who described Iran as an apocalyptic threat. He devoted much of his speech to an argument that Iran, which has repeatedly denied Israel’s right to exist, will have amassed nearly enough enriched uranium by next spring or summer to build a nuclear weapon.

Armed with a cartoonish diagram of a bomb and a red marker, Mr. Netanyahu said Israel would not allow Iran to reach that threshold, which he called Israel’s “red line.”

Iran’s deputy ambassador to the United Nations, Eshaq Al-e-Habib, said Friday in a rejoinder that Mr. Netanyahu’s government was the threat to world peace. Citing what he described as a history of aggression on Palestinians and Arab neighbors by Israel, which Iran calls the Zionist regime, Mr. Habib said Mr. Netanyahu had no right to preach to Iran, which has publicly renounced the use of nuclear weapons.

Mr. Habib also said - as Iranian officials almost always do when talking about Israel - that Israel already has nuclear weapons and has not signed the Non-Proliferation Treaty, which Iran signed in 1968. Both countries are members of the International Atomic Energy Agency, the nuclear proliferation monitor of the United Nations.

“Now, this regime’s prime minister shamelessly and hypocritically, and with hue and cry, and by making baseless and absurd allegations against the exclusively peaceful nuclear program of my country, tries to abuse the tribune of this august assembly,” Mr. Habib said.

He accused Israel of trying to “divert the attention of member states from the danger of its nuclear arsenals, its clandestine nuclear program and its unsafeguarded nuclear facilities, which are the only source of threat to the peace, security and stability in the Middle East and beyond.”

Mr. Habib advised Israel “to obey the repeated calls by the international community, and to accede promptly and without any condition to the N.P.T. as a nonnuclear-weapon party and to place all its nuclear-related facilities under the comprehensive I.A.E.A. verification system.”

Israel has never acknowledged its supply of nuclear weapons. The Arms Control Association, a nonpartisan group in Washington, has reported that Israel possesses between 75 and 200 nuclear warheads.

While Mr. Netanyahu has often hinted that Israel would attack Iran if diplomatic negotiations and sanctions did not halt Iran’s uranium enrichment, he was more explicit on Thursday in his speech about when he might order such a strike, suggesting it would not happen until deep into 2013 - well past the American elections.

Mr. Netanyahu also publicly thanked President Obama for his warnings to Iran, in effect signaling his desire to smooth over a rift between the two over how to deter what both men have called Iran’s nuclear threat.

The White House said in a statement that Mr. Obama and Mr. Netanyahu spoke by telephone on Friday and “discussed a range of security issues, and the President reaffirmed his and our country’s unshakable commitment to Israel’s security.”

The statement also said both men “underscored that they are in full agreement on the shared goal of preventing Iran from obtaining a nuclear weapon.”

While Iran has repeatedly asserted that its uranium enrichment is for peaceful purposes, it has defied Security Council demands for a suspension until questions about its nuclear program are resolved by the International Atomic Energy Agency. Talks aimed at resolving the dispute have stalled since June.

As a signatory to the Non-Proliferation Treaty, Iran has insisted that it is in full compliance with all safeguards and that the Security Council demands amount to big-power bullying. But Iran has not permitted I.A.E.A. inspectors the unlimited access they want, citing security concerns and fears that some inspectors are really spies for Iran’s enemies.

Iran Ridicules Netanyahu’s Bomb-Theatrics