(CNN) -- If international efforts to halt Iran's nuclear program fail, any military action against Tehran should be led not by Israel, but by the United States, former Israeli Prime Minister Ehud Olmert said this week.
"The last resort is a military action," Olmert told "CNN International's Amanpour" in an interview that was shot Sunday and aired Monday. "And I prefer that it would be an American action -- supported by the international community -- if all the other efforts would fail."
Olmert added that the U.S. government should also decide on the extent and the scope of any military action. "Israel certainly could be part of the effort, but Israel should not lead it," he said.
Olmert's comments came days after the former head of the Shin Bet, Israel's internal security service, slammed Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak for their handling of Iran, saying neither inspires confidence.
"I don't trust a leadership that relies on messianic leadership," Yuval Diskin told a public conference Friday night in Israel.
"Our two messiahs from Caesaria and from the Akiorv Towers are not fit to stand at the helm of the government," Diskin said, referring to the respective residences of Netanyahu and Barak.
Olmert described as "quite unusual" the comments from Diskin. "I prefer to distinguish between the personal aspects of what he said and the substantial aspects of what he said. We don't think that the priorities are set in the right way. First priority, as I said, is cooperation with America from a respectful and serious and careful attitude and not trying to teach the president of America or preach to the president of America or blame the president of America, but rather cooperate with him."
Olmert said there is no immediate need for military action against Tehran. "I know one thing: that the Iranian leadership has not gone beyond a certain line for the time being of developing the nuclear program," he said. "And that shows that they are at least thoughtful, which means that they are not rushing, but they are calculating their steps."
Olmert implied, but did not state overtly, that he ordered the Israeli military to destroy Syria's al-Kibar nuclear facility in 2007.
He said he had read about the events in the memoirs of former President Bush. "He is a very honest man," Olmert said. "I don't think that he wrote lies."
The former prime minister said there was a big difference between events at that time and those of today. "The reactor in Syria was about to be operated within days, and therefore there was no time to wait."
In addition, "all the assessments made by all the intelligence agencies that I've heard -- and I've heard all of them -- is that Iran will react and that may trigger a regional war in the Middle East, which would impact the stability of the Middle East, the economic situation, which would have far-reaching consequences."
Olmert also implied that he did not trust the current leaders of Israel to make the right decisions. "You could understand from what I said that maybe something in my trust is lacking," he said.
In response to Diskin's comments, Barak said last week that while he welcomed Diskin's entry into politics, the comments are irresponsible.
"It is both embarrassing and saddening to see the weakening of judgment and responsibility and the low language a man who served the public for years was dragged into," said a statement from Barak's office. "Diskin is acting in a petty, irresponsible manner motivated by personal frustration. He is harming the heritage of generations of Shin Bet heads and the operational norms of the organization."
Other high-profile figures have criticized the Israeli government's handling of Iran.
Meir Dagan, the former chief of Israel's spy agency, the Mossad, has been a frequent and vocal critic of talk about an Israeli strike on Iran, famously calling it a "stupid idea."
Silvan Shalom, Israeli vice premier and Likud party member, told the Jerusalem Post that Diskin should not have spoken in public.
"I think that Diskin was wrong to say what he did, and that when he considers what he said, he will realize that he was wrong," Shalom said.
Diskin's commentary followed remarks by Israel's top general, who said last week that Iran is led by "very rational people" and doesn't appear poised to build a nuclear bomb.
Iran "is going step by step to the place where it will be able to decide whether to manufacture a nuclear bomb," Chief of Staff Lt. Gen. Benny Gantz told Israel's Haaretz newspaper. "It hasn't yet decided whether to go the extra mile."
Those comments were in stark contrast to those of Netanyahu, who suggested to CNN that time is running out for Western sanctions on Iran to have a meaningful effect on Tehran's nuclear program.
The sanctions "are certainly taking a bite out of the Iranian economy," Netanyahu told CNN. But, he said, "They haven't rolled back the Iranian program -- or even stopped it -- by one iota."
CNN's Kevin Flower contributed to this report.