“The UN Atomic Energy Agency (IAEA) has just announced that Iran has substantially increased enrichment, which seems to contradict American statements that have appeared in all the media suggesting that Iran has not yet made the decision whether to develop nuclear weapons.”

Two points of dispute stand out in creating what Sen. John McCain, also on a visit to Israel last week, called the “daylight” between the two countries regarding Iran’s nuclear plan.

The first is the question of what constitutes unacceptable progress toward the manufacture of an armed nuclear device, or, in Barak’s words, Iran’s entry into a “zone of immunity.” The other is the extent of uranium enrichment at a nuclear site near the holy city of Qum, which was highlighted by the IAEA report.

The United States and Israel agree that the secret underground structure is better protected from a possible military strike than other known Iranian facilities. But from that point of agreement, different conclusions are drawn.

Israeli analysts believe Iran is moving fast toward a nuclear military option, and taking advantage of the pressure of sanctions and the time granted by European offers to negotiate in order to assemble all the parts necessary to build a bomb. The United States, which is in the midst of an election year, meanwhile, thinks sanctions may yet bring Iran — “if it is behaving as a rational actor,” in Gilboa’s words — to negotiate.

“The process is preparing everything for the building of bombs, with the aim of creating all the parts and then needing only a very short period of time to assemble a weapon. So it is just playing with words if we say that we don’t know whether they have made a decision. If you produce all the parts, it is obvious that means you intend to produce a bomb,” Gilboa said.

“I think that what Obama wants from Netanyahu next week is a commitment not to strike Iran at least until the American election, to give heavier sanctions a chance and not to surprise the United States.”

Gilboa does not believe Israel would attack Iranian nuclear installations without notifying the Americans beforehand.

Still, he points out, “The current situation is unprecedented. The U.S. has never before asked Israel to refrain from military action, and Israel has never before asked the U.S. for permission. This is all new ground.”

The 1981 Israel Air Force attack on Osirak, Saddam Hussein’s French-built nuclear reactor is now ancient history. In that campaign however, only eight jets were involved.

The New York Times estimated that at least 100 Israeli fighter planes would be needed today for a crippling attack on Iran. At the time of the Osirak strike, the United States angrily condemned Israel. But in 2005, former President Bill Clinton said, “Everybody talks about what the Israelis did at Osirak in 1981, which I think, in retrospect, was a really good thing.”

The current disagreement between Israel and the United States seem not to be on the substance of Iran’s nuclear program, or even on the possibility of a necessary, last-resort, military strike, but on the timetable and method of response to the threat.

Many Israeli analysts believe the Obama administration and Europe are not convinced that the full effect of sanctions has yet been felt. Israelis are concerned that by the time they are felt, possibly by next summer, when Europe’s oil embargo on Iran is scheduled to go into effect, it might be too late.

“What Obama would like is to put the crippling sanctions to the test. He thinks that the sanctions being used this time, alongside the oil embargo, will actually have an impact,” said Tel Aviv University professor Uzi Rabi, the director of the Moshe Dayan Center for Middle Eastern and African Studies.

“He is in effect saying to Israel, don’t surprise us. We want to be updated from A to Z. The second thing, I think Israel is being asked is to play down the shadow war and really just let sanctions work. If the sanctions are going to be fully implemented it could inflict a lethal blow on the Iranian regime, and since what we are talking about is the survival of the regime itself, this could be very effective.”

As to Israel, Rabi says, “It would like to make sure everybody knows that from its point of view, a nuclear Iran is unbearable. This combination of ayatollahs and power is something that poses an existential threat to Israel, and it is something Israel is really afraid of. What Israel thinks is the right thing to do is to make sure the military option is not only on the table, but actually feasible.”

Not many in Israel think that Iran, even with a nuclear weapon in hand, would attack Tel Aviv.

“Based on rational thinking, which is not one of the strongest characteristics of the Middle East, if Iran acquires nuclear weapons, it would be tantamount to suicide were they to use them. Iran would be wiped out by Israel’s second strike capability and by American nukes,” Gilboa said.

“I think they want them in order to acquire hegemony in the Middle East. By becoming a nuclear power they can threaten anybody. The power of threat is much more than the power of destruction.”

Gilboa predicts that next week Netanyahu will ask Obama how he plans to ensure Iran’s non-nuclear status in the event sanctions fail to cripple the nuclear program, and that Obama “will evade the answers.”

Rabi says “Israel is afraid to be left alone. I don’t think Iran would attack Israel. But their actions provide a source of inspiration for lunatic radical movements like Hamas and Hezbollah, and the fact that they are attacking Israelis in Baku, Delhi and Tbilisi, though ineffective for now, show that this is a state that could act in accordance with the modus operandi of a terrorist group. This has very negative implications for the stability of the Middle East.”

Not all Israeli experts see in the commotion of transatlantic visits and consultations evidence of tension between the United States and Israel. Shlomo Shpiro, vice chair of the Department of Politics at Bar Ilan University, believes those claims to be overstated.

“I think there anxiety among some in the U.S. administration who fear that a powerful Israeli military action against Iran could have an impact on the election in November. I don’t think there is tension. A whole range of senior American officials have been visiting Israel almost on a weekly basis.”

“I think the threat assessment is very similar in Washington and in Jerusalem,” he adds. “I think Obama is very concerned about the possibility of Iran getting nuclear weapons. Both are very worried, and both countries agree the process is moving quickly. The disagreement is only about how to prevent or delay it.”

Any Israeli military option, Shpiro says, would be a “last resort.”

“But if it comes to a last resort, I think Israel’s leadership will not hesitate. It all depends on the progress of Iran’s nuclear program and on information that the U.S. and Israel obtain about that program.”

For now, the war of nerves will play on, with Israel pressuring the U.S. and Europe to fully implement severe sanctions as soon as possible, and demanding assurances, perhaps impossible to give, about what the West will do if sanctions do not deter Iran.

The psychological warfare, many say, may lead Iran to believe it can “safely assume it can continue with its plan to build nuclear weapons without much interference,” Gilboa said. “There is a possibility the Iranians are laughing at everybody. For example, why announce sanctions and then say you’ll impose them only in six months?”

“The Iranians are the only ones producing consistent statements, and this is our problem. Too many of the statements coming from the West are confusing and could be interpreted in any number of ways.”