Still, an attack on Iran would not be easy. Probable targets, including the Natanz and Fordo enrichment facilities south of Tehran, lie some 1,000 miles (1,600 kilometers) from Israel.
Experts believe some of the Israeli warplanes could not make the round trip without refueling in flight. Israel, which has eight tanker planes, can refuel an airplane in flight in a matter of minutes, though it's unclear where the task would take place since much of the airspace in the region is hostile. They would also have to contend with Iranian air defense systems.
A pre-emptive Israeli strike would almost certainly draw a fierce Iranian retaliation toward Israeli population centers. Iranian leaders have even suggested they may strike Israel if they felt threatened by the possibility of an Israeli strike.
Iranian officials did not immediately comment on the Israeli report. But in a newspaper interview on Sunday, Iran's foreign minister, Ali Akbar Salehi, dismissed Israel's capabilities.
"Let them try it if they can - if Israel was ready to strike Iran it would have happened by now," he told the Qatari newspaper Al-Waten on Sunday. "We may suffer from this attack, but the Israelis are afraid of the results of such an attack. We won't sit idly by if it happens."
The revelations come ahead of a charged Israeli election season and highlight a broad range of rifts among Israeli leaders and officials.
At the meeting in 2010, Barak said Ashkenazi told him the military wasn't able to carry out the attack. "Ultimately, at the moment of truth, the answer given was that the ability didn't exist," Barak told Uvda.
But Ashkenazi denies that. He was quoted by the close associates as saying he instead told Barak that the military had prepared a viable option and was ready to carry it out but that such a mission would be a strategic mistake.
Barak countered that offering such an assessment was not Ashkenazi's job.
"A chief of staff needs to build the operational capacity. He should tell us professionally if we can operate or not and he can and should give his recommendation, but an operation can go through even if he opposes it," Barak said.
Barak said the alert was part of Israeli preparations and that a final decision to attack was never made.
It was unclear to what extent the opposition of the security officials contributed to the decision to hold back. The positions of their successors are less clear, though they too are believed to be wary of a military option. Nevertheless, Israeli security officials say that over the past two years the Israeli military's capabilities have improved to overcome some obstacles that were previously in place.
Netanyahu told the program that that the ultimate responsibility for protecting Israel was on his shoulders.
"Any prime minister of Israel who cannot act on things that are cardinal to the existence of the state, to ensuring its future and safety and is dependent on the agreement of others, is not worthy of leading," he said, adding that before Israel was a state it had to beg for help from others when threatened with destruction.
"Well today we do not beg, we prepare," he said.
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.