According to the IAEA report, more than 3,000 pounds of low enriched uranium had been produced, in comparison to just over 2,220 pounds mentioned in an IAEA report in February, an amount that experts and US officials subsequently said was sufficient to process into enough weapons-grade uranium for a nuclear warhead.

According to Israeli defense officials, the Iranian strategy is to enrich uranium to low levels - around 4 percent - in accordance with a civilian nuclear energy program. At the same time, the regime is rapidly constructing centrifuges which, if and when the decision is made, would be capable of fast and mass production of the high-enriched uranium needed for a nuclear weapon.

Due to this strategy, the IAEA cannot say for certain that Iran is developing nuclear weapons, even though it suspects that the Islamic Republic was seeking weapons up until several years ago.

The likely scenario, therefore - in the event that the dialogue the US has asked to hold with Iran fails - is that the regime will take the low-enriched uranium, run it through the modern centrifuge farm it has constructed and produce an amount of high-enriched uranium sufficient for several nuclear weapons.

IN RESPONSE, Israeli strategy is twofold. As Defense Minister Ehud Barak said this week, during a meeting with US Secretary of Defense Robert Gates, Israel is willing to wait for the results of the dialogue Washington plans to hold with Teheran. But, as Barak made clear at an ensuing press conference, Israel's suggestion is not to take "any option off the table." Israel itself definitely does not plan to do so.

Last week, US Air Force commander Gen. Norton A. Schwartz visited here for the first time. According to military sources, talks he held with defense officials focused on issues such as Iran.

A week before that, Israel and the US held a joint exercise of the X-Band radar, which the Bush administration deployed in the Negev late last year. The exercise was held at EUCOM headquarters in Germany, and it revealed that, when operating in conjunction with Israeli early-warning systems, the X-Band enables Home Front Command to issue an alert about an incoming missile between five and seven minutes before impact.

The testing of the X-Band came on the heels of the testing of the Arrow missile defense system on the US West Coast, and following the navy's decision to send a submarine and several of its advanced Sa'ar 5 class missile ships through the Suez Canal for the first time in years, a move understood to be a signal to Iran of its military preparations. The IAF has also been increasing its overseas training.

THE MAIN question, though, is what the US plans to do. The parade of American officials to Jerusalem this week - including Gates, special envoy George Mitchell and National Security Adviser James Jones - was aimed at coordinating efforts and ensuring that both countries be on the same page.

About the Gates-Barak meeting, defense commentators said that what they heard in the room was far different from what Gates said outside.

"The Americans and we are on the same page, and are also very pessimistic about the outcome of a dialogue, particularly in light of the political mess in Iran today," explained one senior official. For that reason, Gates said the US will not wait forever for Iran to begin negotiations.

The differences, however, begin to emerge when the sides start talking about "the day after" the dialogue - depending, of course, on its success or failure.

If it is a failure, and the US decides to increase sanctions - particularly against Iran's refined fuel imports - Israeli officials are skeptical that such a move would be possible without Russian support, something that President Barack Obama has yet to obtain.

But senior IDF officers said this week that they were encouraged by remarks Joint Chiefs of Staff Chairman Adm. Mike Mullen - who talks weekly with his Israeli counterpart Gabi Ashkenazi - made in recent interviews. While Mullen said that an Israeli strike would be destabilizing for the region, he also said that Iran is very focused on obtaining a nuclear capability. In addition, he accepted Israeli time estimates regarding the nuclear program, meaning that time is running out. These remarks are understood within the defense establishment as being aimed first and foremost at the White House.

Security and Defense: Ticking... and talking