By Elise Labott
Israeli officials were telling CNN's Security Clearance just a month ago that the United States and Israel were cooperating closely on intelligence sharing over Iran.
The latest U.S. assessment gave the two countries their closest understanding yet of the scope and pace of the development of the Iranian effort, the Israelis said.
But the close cooperation belies a heated policy debate – one becoming more public – about when military action would be required to take out the nuclear program.
Israeli Prime Minister Benjamin Netanyahu is displaying growing impatience with what he says is a lack of clarity by the Obama administration on so-called "red lines" that Iran cannot cross if it wants to avoid war.
"Iran will not stop unless it sees clear determination by the democratic countries of the world and a clear red line," Netanyahu warned in an interview with the Canadian Broadcasting Company.
"I don't think that they see a clear red line and I think the sooner we establish one, the greater the chances that we won't need other types of action," the Israeli leader said.
House Intelligence Committee Chairman Mike Rogers, R-Michigan, spoke publicly about a meeting he attended last month in Israel during which he said Netanyahu blew up at U.S. ambassador Dan Shapiro because he was "at wit's end" over what he saw as foot-dragging by the administration.
"Right now, the Israelis don't believe that this administration is serious when they say all options are on the table and more importantly, neither do the Iranians. That's why the program is progressing," Rogers said in an interview with Michigan's WJR radio.
Speaking to the Israeli press, Shapiro has dismissed accounts of a heated closed-door exchange.
Support for Israel has become a contentious topic in the presidential campaign. Republican Mitt Romney has called President Barack Obama weak when it comes to supporting Israel and countering Iran.
"The uncertainty about where the United States' position is on those questions has created lots of problems and anxiety that I think doesn't serve the world well and doesn't serve peace well," Rogers said.
Iran has stepped up production of high-grade enriched uranium and has re-landscaped one of its military bases in an apparent effort to hamper a United Nations inquiry into its nuclear program, the U.N.'s International Atomic Energy Agency said in a report last week.
Israel feels a greater sense of urgency with talks aimed at curbing Iran's nuclear ambitions failing to produce an agreement and sanctions not having the intended impact.
Concerns in Washington that Israel could launch a pre-emptive strike on Iran's nuclear facilities prompted a wave of visits this summer to Israel by several top U.S. officials, including Secretary of Defense Leon Panetta, Secretary of State Hillary Clinton, and National Security Adviser Tom Donilon.
Israeli anxiety has not compelled the administration to produce a clear statement on the consequences Iran would face for continuing to pursue its nuclear program, which Tehran insists is peaceful.
Far from establishing a threshold for military action, the closest White House spokesman Jay Carney would go on Monday was to repeat the commonly-used phrase "the president is committed to prevent Iran from acquiring a nuclear weapon."
The debate between the United States and Israel centers on a decision by Iran to acquire a nuclear bomb versus its "breakout capacity" to do so.
Israel worries that Iran's nuclear development will progress past a point where the Israelis can stop Iran from obtaining a nuclear weapon themselves. The United States, with its superior military capabilities, has greater latitude to decide how far is too far.
Carney declined to provide detail about the U.S. threshold and offered a 'we'll know it when we see it' explanation of the "so called breakout move."
It certainly doesn't look like the United States has a confrontation with Iran in its sights.
With the presidential election less than two months away, Israeli officials tell CNN they do not view the Obama administration as seriously considering any action in the next few months.
Asked this week during an interview in Russia if the Obama administration would set out red lines for Iran, Secretary of State Hillary Clinton said: "We're not setting deadlines."
Clinton said 'we're watching very carefully" what they do because "it's always been more about their actions than their words."
But Rogers warned in his radio interview that he believed Israel could conduct a strike on its own absent clarity by the administration.
"If I were betting my house today, I would guess that they probably will do it, if we don't have a change in more clear red lines from the United States," he said.