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The former head of Israel's Shin Bet security agency has accused the country's political leaders of exaggerating the effectiveness of a possible military strike against Iran, in a striking indication of Israel's turmoil over how to deal with the Iranian nuclear program.

Yuval Diskin said Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak -- who have been saber-rattling for months -- have their judgment clouded by "messianic feelings" and should not be trusted to lead policy on Iran. Diskin, who headed Shin Bet until last year, said a strike might actually accelerate the Iranian program.

Iran says its nuclear program is for peaceful purposes. Israel, like the West, believes that Tehran is developing weapons technology, but there is intense debate over whether international economic sanctions accompanying the current round of negotiations might prevent Iran from developing a bomb, or whether at some point a military strike should be launched.

Diskin's comments deepened the sense that a rift is growing between the hawkish Netanyahu government and the security establishment over the question of a strike.

In Israel, security figures carry clout well into retirement. Although they frequently pursue political careers, Diskin had been seen as relatively apolitical, perhaps lending his words even greater weight.

"I don't have faith in the current leadership of Israel to lead us to an event of this magnitude, of war with Iran," Diskin said at a public meeting Friday, video of which was posted on the Internet the next day and quickly became the lead news item in Israel.

"I do not believe in a leadership that makes decisions based on Messianic feelings," he continued. "I have seen them up close. They are not messiahs, these two, and they are not the people that I personally trust to lead Israel into an event."

Diskin said it was possible that "one of the results of an Israel attack on Iran could be a dramatic acceleration of the Iran program ... They will have legitimacy to do it more quickly and in a shorter timeframe."

Spokesmen for Netanyahu and Barak both refused comment on the issue.

Further complicating the picture is the widely held belief that Israel's threats are actually a bluff of historic proportion and that indeed they have been effective in compelling the world to boycott Iranian oil and isolate its central bank.

From that perspective, criticism such as Diskin's, based on a literal approach, could be presented as simplistic and damaging.

Israeli security officials have taken issue with the political leadership on several issues: whether sanctions will make a strike unnecessary, whether a strike will be militarily effective, and whether Israel should strike unilaterally if it cannot gain American approval.

Diskin's speech came days after the country's current top military commander, Lt. Gen. Benny Gantz, also seemed to disagree with the country's leadership on the likelihood that Iran will pursue a nuclear weapon.

Gantz told The Associated Press this week that Iran is seeking to develop its "military nuclear capability," but that the Islamic Republic would ultimately bow to international pressure and decide against building a weapon. The key to that pressure, he said, were sanctions and the threat of a military strike.

One of the first criticisms voiced by a security figure came last summer from Israel's recently retired spy chief Meir Dagan. He called a military strike against Iran's nuclear program "stupid." Dagan, who headed the Mossad spy agency, said an effective attack on Iran would be difficult because Iranian nuclear facilities are scattered and mobile, and warned it could trigger war.

Other senior figures with security backgrounds have questioned whether Israel should act alone, as Netanyahu insists the country has a right to do.

Last month Shaul Mofaz -- a former military chief and defense minister who has since been elected head of the opposition Kadima Party -- said the threats of an imminent military strike are actually weakening Israel. Mofaz, who was born in Iran and moved to Israel as a child, said Israel "is not a ghetto" and that despite its military might must fully coordinate with the U.S. on any plan to strike Iran.

Dan Halutz, who led the military from 2005 to 2007, also criticized Netanyahu last month for invoking Holocaust imagery in describing the threat posed by a nuclear-armed Iran. "We are not kings of the world," Halutz said. "We should remember who we are."

A recent poll suggested the public agrees. The survey, conducted by the Israeli Dahaf agency for the University of Maryland, said 81 percent of Israelis oppose a solo attack on Iran. At the same time, it said two-thirds of Israelis would support military action if coordinated with Washington. The poll, released last week, questioned 500 Israelis and had a margin of error of 4.3 percentage points.

In a recent report the U.N. nuclear agency found Iran continues to enrich uranium -- a key step toward developing a bomb. Although few in Israel would dispute that a nuclear-armed Iran is an existential threat, debate has revolved around the cost-benefit analysis of an attack.

On the cost side is the possible retaliation, in the form of Iranian missiles as well as rocket attacks by Iranian proxies Hezbollah and Hamas on its northern and southern borders. Especially daunting is the prospect of sustained missile strikes on Tel Aviv, a bustling business and entertainment capital whose populous is psychologically ill-prepared for a homefront war.

It also would likely cause oil prices to skyrocket at a time when the global economy is already struggling -- risking a new recession for which Israel would absorb much if not most of the blame. Some also fear that Iran might attack American targets in response to any Israeli strike -- a scenario that could directly influence the outcome of this fall's U.S. presidential election.