The man who ran Israel’s Mossad spy agency until January contends that Israel’s top leaders lack judgment and that the anticipated pressures of international isolation as the Palestinians campaign for statehood could lead to rash decisions — like an airstrike on Iran.

The former intelligence chief, Meir Dagan, who stepped down after eight years in the post, has made several unusual public appearances and statements in recent weeks. He made headlines a few weeks ago when he asserted at a Hebrew University conference that a military attack on Iran would be “a stupid idea.”

This week Mr. Dagan, speaking at Tel Aviv University, said that attacking Iran “would mean regional war, and in that case you would have given Iran the best possible reason to continue the nuclear program.” He added, “The regional challenge that Israel would face would be impossible.”

Mr. Dagan went on to complain that Israel had failed to put forward a peace initiative with the Palestinians and that it had foolishly ignored the Saudi peace initiative promising full diplomatic relations in exchange for a return to the 1967 border lines. He worried that Israel would soon be pushed into a corner.

On Thursday he got more specific, naming Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak, but this time through a leaked statement to journalists. The statement had to do with his belief that his retirement and the retirement of other top security chiefs had taken away a necessary alternative voice in decision making.

In recent months, the military chief of staff, Gabi Ashkenazi, and the director of the Shin Bet internal security agency, Yuval Diskin, have also stepped down. Mr. Dagan was quoted in several newspapers as saying that the three of them had served as a counterweight to Mr. Netanyahu and Mr. Barak.

“I decided to speak out because when I was in office, Diskin, Ashkenazi and I could block any dangerous adventure,” he was quoted as saying. “Now I am afraid that there is no one to stop Bibi and Barak,” he added, using Mr. Netanyahu’s nickname.

Journalists recalled that Mr. Dagan, who had refused contact with the media during his time in office, called a news briefing the last week of his tenure and laid out his concerns about an attack on Iran. But military censorship prevented his words from being reported.

“Dagan wanted to send a message to the Israeli public, but the censors stopped him,” Ronen Bergman of the newspaper Yediot Aharonot said by telephone. “So now that he is out of office he is going over the heads of the censors by speaking publicly.”

Mr. Dagan’s public and critical comments, at the age of 66 and after a long and widely admired career, have shaken the political establishment. The prime minister’s office declined requests for a response, although ministers have attacked Mr. Dagan. He has also found an echo among the nation’s commentators who have been ringing similar alarms.

“It’s not the Iranians or the Palestinians who are keeping Dagan awake at night but Israel’s leadership,” Ari Shavit asserted on the front page of the newspaper Haaretz on Friday.

“He does not trust the judgment of Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak.”

It was Mr. Shavit who interviewed Mr. Dagan on stage at Tel Aviv University this week. And while Haaretz is the home of the country’s left wing, Mr. Shavit is more of a centrist.

“Dagan is really worried about September,” Mr. Shavit said in a telephone interview, referring to the month when the Palestinians are expected to ask the United Nations General Assembly to recognize their state within the 1967 border lines. The resolution is expected to pass and to bring new forms of international pressure on Israel. “He is afraid that Israel’s isolation will cause its leaders to take reckless action against Iran,” he said.

Nahum Barnea, a commentator for Yediot Aharonot, wrote on Friday that Mr. Dagan was not alone. Naming the other retired security chiefs and adding Amos Yadlin, who recently retired as chief of military intelligence, Mr. Barnea said that they shared Mr. Dagan’s criticism.

“This is not a military junta that has conspired against the elected leadership,” Mr. Barnea wrote. “These are people who, through their positions, were exposed to the state’s most closely guarded secrets and participated in the most intimate discussions with the prime minister and the defense minister. It is not so much that their opinion is important as civilians; their testimony is important as people who were there. And their testimony is troubling.”

This concern was backed by a former Mossad official, Gad Shimron, who spoke Friday on Israel Radio.

Mr. Shimron said: “I want everyone to pay attention to the fact that the three tribal elders, Ashkenazi, Diskin and Dagan, within a very short time, are all telling the people of Israel: take note, something is going on that we couldn’t talk about until now, and now we are talking about it. Something is rotten in the state of Denmark, and that is the decision-making process. The leadership makes fiery statements, we stepped on the brakes, we are no longer there and we don’t know what will happen. And that’s why we are saying this aloud.”

Neither Mr. Ashkenazi nor Mr. Diskin has made any public statements, and one high-level military official said he did not believe that they shared Mr. Dagan’s views.

While in office, Mr. Dagan served three prime ministers, was reappointed twice and oversaw a number of reported operations that Israelis consider great successes — forcing delays in Iran’s nuclear program through sabotaging its computers and assassinating scientists; setting the groundwork for an attack on a nuclear reactor in Syria in 2007; and assassinating Imad Mughniyeh, a top Lebanese Hezbollah operative, in 2008.

When Ariel Sharon, the prime minister in 2002, appointed Mr. Dagan, he was reported to have told him he wanted “a Mossad with a knife between its teeth.” Mr. Dagan is widely thought to have complied and is not seen as a soft-hearted liberal.

Although Mr. Dagan is barred by law from elected office for three years, some suspect that he is laying the foundation for a political career. Others, like Yossi Peled, a government minister from the Likud party and a former military commander, think he is doing more harm than good.

“It damages state security,” Mr. Peled said on Israel Radio. “There is no need to give the other side directions of thought, activity or readiness. I am sure he is very worried and is acting out of good intentions, but I still think there are things that shouldn’t be declared in public.”