A former Israeli national security adviser said Wednesday that the prime minister and the defense minister told him this week they had not yet decided to attack Iran’s nuclear facilities and could be dissuaded from a strike if President Obama approved stricter sanctions and publicly confirmed his willingness to use military force.

“There is a window of opportunity,” said the official, Uzi Dayan, a former deputy chief of staff in the military. “This window is closing, but if the United States would be much clearer and stronger about the sanctions on one hand and about what can happen if Iran won’t make a U-turn — there is not a lot of time, but there is still time to make a difference.”

Mr. Dayan, 64, who is currently the chairman of the national lottery, said he spent more than an hour each with Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak at their homes on Monday. He was being considered for the post of minister of the military’s Home Front Command, which he said he turned down, and therefore extensively discussed with the two leaders the security threats that Israel is facing, particularly from Iran. (Another leading security official, Avi Dichter, is expected to be confirmed by Parliament as the home front minister on Thursday.)

The meetings came during a week of intensifying public discussion about the possibility of a unilateral Israeli attack on Iran, fueled by a series of leaks to journalists by supporters and opponents of such a strike. The media blitz seems to have awakened the Israeli public — left-leaning intellectuals staged protests, and there were long lines at gas mask distribution centers — and to have engaged Washington, where two top defense officials tried to tamp down the talk on Tuesday.

Mr. Dayan’s assessment seems to buttress the theory that the collective saber rattling is part of a campaign to pressure the Obama administration and the international community, rather than an indication of the imminence of an Israeli strike. Many analysts here believe that hawkish statements by Mr. Netanyahu and Mr. Barak this spring led to the harsher sanctions now in place, and that this is essentially Round 2.

“It could be only a tactical tool in order to push some of the other countries,” said Giora Eiland, another former national security adviser, who is a senior research fellow at the Institute for National Security Studies in Tel Aviv. “They believe that in order to create enough pressure, to enhance the economic sanctions, the only way to do it is by creating the credibility behind the military option. The only way to create credibility is, No. 1, to improve the military readiness and, No. 2, to make a clear announcement that’s what we mean to do.”

While Mr. Netanyahu and Mr. Barak have been criticized as “messianic” in their thinking on the Iranian nuclear issue and are widely viewed as ready, if not eager, to take military action to stop it, Mr. Dayan said they would prefer that the United States led any attack, even if that meant waiting until after the November presidential election. But “they have to make the decision whether to strike or not before November,” he said, so they need to hear from Mr. Obama “in the coming two weeks, in the coming month.”

“I’ve known them a very long time,” said Mr. Dayan, who served with Mr. Netanyahu and Mr. Barak in the elite combat unit Sayeret Matkal. “They will make such a decision of striking only if they feel that there is no other way. They will do it only as the last, last thing, but then they will be pretty determined about it.”

Eytan Gilboa, a political scientist at Bar-Ilan University, said the series of leaks, in which both Washington and Jerusalem are trying to influence each other and the Israeli public, “exposes some serious differences between the two countries.”

“It’s an issue of trust and time that are dividing now Israel and the United States, and this is a little bit dangerous,” Mr. Gilboa said. “If you have trust, time is less important. If you have time, then mistrust is also not so bad. If you have both mistrust and a shortage of time, then it’s a recipe for disagreement and misperception.”

Emily Landau, an Iran specialist at the Institute for National Security Studies, said the danger was that the latest round of public discussion primarily framed the Iranian nuclear question as a threat to Israel, rather than as a global issue of nuclear proliferation. While Mr. Obama said in March that his policy was one of prevention, not containment, Ms. Landau noted, “he stopped short of putting some kind of red line behind that.”

“The red line needs to be coming from Washington to Iran; those are the red lines that matter,” she said. “If Obama would make a clear statement that would have the double effect of deterring Iran and reassuring Israel, it would take all the air out and maybe allow decision makers to hold on to something that’s strategically real.”

For now, with newspapers awash in headlines about holes in domestic preparedness, some Israelis are scrambling to get gas masks, which about 53 percent of the public already has. At Hadar Mall in Jerusalem, the wait on a recent day was about two hours, though people could take a number and shop for school supplies until it was called.

About 30 people sat quietly in chairs as a film loop describing how to use the masks went mostly unwatched.

Mordechai Kirschenbaum, a media consultant and a co-host of a television talk show, said the public was a bit shocked by the airing of different views on how to handle the situation.

“When Israel usually went to war, there was never such a debate prior to the action,” Mr. Kirschenbaum said. “The public is, on one hand, quite scared because you see so many people that are experienced leaders from the past rejecting it and speaking publicly against it. But in the back of their minds they think that maybe Netanyahu and Barak are using it to strengthen the pressure on Washington and on the Iranians and they don’t really mean it.”