Israeli Strike on Iran Would Be ‘Stupid,’ Ex-Spy Chief Says

The intelligence official, Meir Dagan, who retired in early January after eight years as director of Mossad, the Israeli intelligence service, made the remarks at a conference here on Friday. His assessment contradicts the policy of the country’s political leaders, who have long argued in favor of a credible military option against Iran’s nuclear program.

The defense minister, Ehud Barak, criticized Mr. Dagan after his comments were widely publicized in the Israeli news media on Sunday.

Mr. Barak, saying that Mr. Dagan deserved credit for his contributions to state security, contended that he was “not wise to share his thoughts, legitimate as they may be,” with the general public.

“In the end of the day, these issues and decisions belong by their nature to the political echelon,” Mr. Barak said, adding that he was not sure that Mr. Dagan’s assessment was correct.

Iran has maintained that its nuclear program is for peaceful purposes, but Israeli, American and European officials believe that it is intended to produce nuclear weapons.

Independent analysts said that such a public stand by a respected figure like Mr. Dagan would complicate any plans the government might have to attack Iran.

Mr. Dagan, speaking for the first time in public since his retirement, was addressing a conference of senior public servants. His remarks were confirmed by a person who attended the conference, which was held at Belgium House, the faculty club of the Hebrew University of Jerusalem.

Mr. Dagan is known to have long opposed military action against Iran, but he had never said so publicly. Mr. Dagan, who also said Friday that Iran must not be allowed to produce nuclear weapons, has advocated covert means of setting back the Iranian program.

Israel considers the prospect of a nuclear-armed Iran as an existential threat.

Speaking last week at a ceremony marking Israel’s Holocaust Remembrance Day, Prime Minister Benjamin Netanyahu called on the world to “unequivocally condemn those who call for the obliteration of the Jewish state.”

“Iran is even arming itself with nuclear weapons to realize that goal, and until now the world has not stopped it,” he said. “The threat to our existence, to our future, is not theoretical. It cannot be swept under the carpet; it cannot be reduced. It faces us and all humanity, and it must be thwarted.”

It is not the first time that Mr. Dagan has courted controversy where Iran is concerned since he left office. In January, he told a group of Israeli reporters that he believed Iran would not be able to build a nuclear weapon before 2015, a year or more later than other Israeli estimates.

His revised assessment was based on obstacles that Iran has faced, including technical difficulties and covert actions against its nuclear program by intelligence agencies, according to Israeli news reports.

Some Israeli officials reacted furiously, worried that Mr. Dagan’s comments could reduce pressure on Iran.

But other Israelis, including two other former leaders of Mossad, said it was important for Mr. Dagan to be able to express his opinion. One official, who spoke at the time on the condition of anonymity because of the subject’s delicacy, said, “It has never been about when exactly they will get the device.”

The real challenge over the next 12 to 18 months, the official said, is to prevent Iran from reaching the threshold of nuclear weapons capability. An unexpected technological breakthrough in Iran is possible, he said.

Arguing that this was a time for more diplomatic pressure, not less, the official said that Mr. Dagan’s 2015 assessment might have been partly intended to quiet the drums of war, but that it was nevertheless “really unfortunate.”