The Yom Kippur War, in Israel, marked the end of the age of innocence.

Generals, previously untouchable, were stripped of their commands. The prime minister was ousted from office by popular demand. The tremors of the debacle eventually pried open the grip of the Labor-led left and, for the first time in the history of Zionism, ushered in an ideologically right-wing leadership.

Thursday’s revelations from previously classified testimony to the Agranat Commission, which investigated the war, fill in the already grim picture of October 1973 — of arrogance tinged with ineptitude at the very top, which produced, for some, a lack of faith in leaders that endures to this day.

The commander of the northern front, Yitzhak Hofi, testified to the Agranat Commission that despite the evidence of an enormous armored presence near the border, and despite explicit information passed on to him from the command’s chief intelligence officer, he was told, just days before the war, that the chance of war was low and that the reports were insignificant. When he called military intelligence headquarters, Hofi told the commission, none of the relevant officers was on duty. They were at home.

Only at six in the morning on Yom Kippur, October 6, was he told that war would break out and even then the stated time was six in the evening rather than the actual two in the afternoon.

Alfred Eini, an aide to Mossad chief Zvi Zamir, shocked commission members when he said that Zamir apparently “didn’t get” the urgency of a midnight cable from the Mossad’s man in Cairo. He told the five commission members – two former IDF chiefs of staff, two sitting Supreme Court justices and one state comptroller – that “never before” had the man asked for an urgent personal meeting with the head of the Mossad and that Zamir seemed drowsy, even though it was the Mossad that had been warning of imminent war for days.

Finally, the prime minister’s military attaché told the commission that the Mossad’s opinion of imminent all-out war on two fronts was never brought to him in an explicit manner; on account of inter-agency bureaucracy, it was buried in a sheath of material.

These are details that flesh out the picture of what Abraham Rabinovich, author of “The Yom Kippur War”, called “an existential earthquake” — a war that claimed 2,688 Israeli lives and served as “a standing reminder of the consequences of shallow thinking and arrogance.”

Rabinovich, in his superb reportage of the war, spread the blame around: from military intelligence head Eli Zeira to Prime Minister Golda Meir to southern front commander Shmuel “Gordish” Gonen – a tragic figure who was deemed unworthy of further command positions and exiled himself to central Africa.

Today, though, with Israel facing the looming challenge of a nuclear Iran, Israeli political and military leaders seem split: many of the military men look at 1973 and point to the failures of leadership; many of the politicians, certainly the defense minister, have their time clocks set on 1967, when the need for preemptive action trumped staunch American resistance.

Back in 1973, Israel’s current Defense Minister Ehud Barak returned from studies in the United States to command a tank battalion in the Yom Kippur War. He fought in the southern front and even helped rescue the trapped paratroopers in one of the deadliest and most senseless battles of the war, in what is known as the Chinese Farm.

When Barak looks at today’s reality, and especially at an Iran closing in on the bomb, he evidently focuses not on the appalling incompetence of 1973 but on the heroics of the late spring of 1967. Numerous recently retired security chiefs have made plain their opposition to preemptive action in Iran, and some of the current security chiefs are widely reported to share the view. But Barak has repeatedly indicated that preemptive action now, however risky and complex, is far preferable to grappling with a nuclear Iran later on. Several months ago, according to Channel 10 reporter Alon Ben-David, he told the IDF General Staff that “with this kind of General Staff we never would have won in the Six-Day War.”

Meir Dagan, the former head of the Mossad, by contrast, has acknowledged that he views today’s challenges through the lens of the Yom Kippur War. He told Ilana Dayan in an unprecedented television interview in which he openly aired his disagreement with a sitting prime minister — terming a preemptive strike against Iran at this time a disaster — that he was speaking from his “formative experience” in 1973.

Dagan fought on the eastern side of the Suez Canal 39 years ago. He was part of a small commando team in Ariel Sharon’s division that hunted down Egyptian commandos on Israeli soil. The lack of coherence from the leadership, both before and during the war, sharply increased the number of Israeli dead. The leadership emitted “a sense of complete confidence,” Dagan said bitterly. “We will know everything. We know, there won’t be a war.”

His primary lesson of the war, Dagan said, was that just because “people were elected it does not render them utterly immune from making mistakes.”

Avigdor Kahalani, a decorated IDF veteran who commanded an armored battalion on the Golan Heights in the Yom Kippur War, repelling a far bigger Syrian force with a hastily assembled tank unit amid battlefield chaos, said Thursday that the chain of failure that so afflicted the Israeli leadership in 1973 simply “could not happen today.” Sufficient safeguards had long since been instituted, Kahalani said, to ensure that vital channels of communication worked effectively and that critical evidence could not be overlooked.

Israelis can only fervently hope that this is indeed the case, as the country’s leaders weigh fateful decisions on Iran — their mindsets shaped both by the preemptive successes of 1967, and the hubris and incompetence of 1973.