Not long after the end of Yom Kippur War in 1973, future Israeli Prime Minister Menachem Begin—then a new member of the country’s legislature—erupted in outrage on the floor of the Knesset. “Why didn’t they get the military equipment up onto the line?” he cried. The war, an 18-day battle between Israel and the combined forces of Egypt and Syria, resulted in the deaths of over 2,000 Israeli troops, shocked the country’s political establishment, and dealt a blow to the military’s confidence. Begin wanted to know why the government had not prepared for the conflict.

Today, Israelis are asking themselves eerily similar questions. After Hamas killed more than 1,000 people in an unprecedented attack in Israeli territory on October 7, Israelis want to know why their country’s vaunted intelligence services did not see Hamas’s incursion coming. They ask why the Israeli military had too little defensive equipment and personnel situated on the Gaza border.

The Yom Kippur War differed in obvious ways from today’s Israel-Hamas conflagration. It was a war between sovereign states and conventional armies. Its instigators—Egypt and Syria—wanted to regain territory lost to Israel in an earlier war. It was fought in the shadow of the Cold War. Moscow and Washington helped the combatants and negotiated the cease-fire that ended it. But to Israelis, the humiliating surprise of Hamas’s attack feels painfully reminiscent of Egyptian President Anwar Sadat’s shock 1973 invasion.

The parallels go deeper. Then, as now, Israel had enjoyed a period of astounding economic prosperity before the outbreak of the war. Then, as now, before war broke out, Israelis knew that a surprise attack was a possibility, but the country’s politics were dominated by relative confidence when it came to its borders. Israel had won a stunning victory in the 1967 war, routing six Arab states and quadrupling its territory. Not since antiquity had Jews felt so secure: the Bible records that the ancient Hebrews needed seven days to conquer Jericho.

But the 1967 win brought victory without finality. Egypt remained determined to recoup its losses. Meanwhile, Israel’s confidence helped lead it into a set of assumptions that set it up for a sneak attack six years later—a set of assumptions with parallels to assumptions Israel seems to have made in advance of Hamas’s attack.

A cease-fire ended the Yom Kippur War after Israeli forces surrounded the Egyptian Third Army and came within artillery range of the suburbs of Damascus. But the Israeli public considered the government’s failure to foresee the war’s outbreak unforgivable, and the government was compelled to launch a broad investigation into its own mistakes. In testimony before the commission, an Israeli intelligence officer acknowledged that the military made its mistaken assessment that war in 1973 was implausible “based on what was happening in Cairo”—based, in other words, on cutting-edge surveillance technology that allowed it to eavesdrop on high-level discussions—rather than on glaringly obvious signs of an Egyptian military buildup near the Suez Canal.

When the guns fall silent, Israel is almost certain to convene the same kind of inquiry. Although the 1973 commission’s report ran to 2,200 pages, some big lessons from 1973 may have gone unlearned—lessons that Israel needed to understand then and still does now.

CHUTZPAH

After the Six-Day War, Israel’s military capacity exploded: between 1967 and 1973 it added, among other things, 178 A-4 Skyhawk fighter jets, 110 F-4 Phantom jets, and nearly 2,000 tanks. In that same time frame, the Israeli economy grew by an astonishing 85 percent. For months after the Six-Day War ended, numerous signs still dotted the landscape along Israel’s original 1948 border that read DANGER! BORDER AHEAD. On one of them, somebody had spray-painted the word NO in front of BORDER.

But the truth was that the conflict had never really ended. Just weeks after the war’s end, Egypt sank the Eilat, an Israeli naval destroyer, and Israel retaliated by shelling Egyptian cities along the Suez Canal. The Egyptian president at the time, Gamal Abdel Nasser, refused to recognize Israel’s statehood and remained dedicated to retaking the Sinai Peninsula, which Israel had seized during the conflict; he often declared “that which was taken by force will be returned by force.” Open conflict simmered throughout 196970. Four hundred and forty Israelis and tens of thousands of Egyptians were killed. Once the Soviet Union supplied Egypt with advanced SAM-3 missile systems, the Israeli air force began to lose an alarming number of planes. Multiple efforts by the United States and the UN to broker peace foundered.

After Nasser died suddenly of a heart attack, in 1970, he was succeeded by Sadat. In many Egyptians’ minds, Sadat compared poorly with his predecessor; he was often maligned as Nasser’s “poodle.” In street protests, crowds chanted, “Gone is the giant; the donkey has taken his place.” Foreign leaders also rated Sadat badly. On the record, officials spoke of him as a “transitional leader.” In 1970, an Israeli intelligence study concluded that Sadat’s “intellectual level was low,” and a late 1972 update added that he was “weak.” Muhammad Hafiz Ismail, who was Egypt’s national security adviser from 1971 to 1973, claimed that U.S. Secretary of State Henry Kissinger had assured him that if Egypt commenced another war, “Israel will win once again, and more so than in 1967.”

Sadat, however, quickly showed that he was no weakling. Facing a failed coup attempt in 1971, a bankrupt economy, and a military officer corps aching to avenge Egypt’s 1967 loss, Sadat concluded that he had to go to war. But he did what Nasser had never done: he kept the border relatively quiet, sidelined entrenched officers, and appointed a competent group of generals headed by Saad Shazly, a junior but highly regarded career soldier.

Shazly and a group of handpicked officers then made a sober assessment of the Egyptian military’s strengths and weaknesses and crafted a well-thought-out war plan against Israel. Shazly concluded that, at least to start, he did not have to take the whole Sinai Peninsula but merely had to shock Israel, by advancing just six miles into enemy territory and inflicting casualties. A war of attrition and international pressure, he reckoned, would then force Israel to withdraw to its pre-1967 borders. He devised ways to neutralize the Israeli air force using Soviet surface-to-air missiles and Israeli armor using shoulder-fired rockets.

Most of all, Shazly’s plan depended on the element of surprise. He employed a tactic that the Soviet Union had successfully used to fool Western intelligence agencies when it invaded Czechoslovakia in 1968: conduct repeated training exercises ahead of the attack, making it hard for observers to distinguish between normal military activity and offensive preparations. The Egyptians mobilized and demobilized their army along the Suez Canal no less than 22 times between January 1, 1973 and October 1, 1973.

Only a handful of Egypt’s most senior military officers knew that on the 23rd mobilization, on October 6, the army would be ordered to cross the canal. Out of 8,000 Egyptian troops that Israel later captured, only one said he knew about the planned attack more than a day ahead of time. Practically all the others found out the same morning.

But this only tells part of the story. Israel underestimated the Egyptian army as a whole: although Israel built a string of forts to monitor Egyptian activities across the border, its leaders felt it was impossible that Cairo’s troops were capable enough to overwhelm them in a lightning attack. In 1971, the Israelis ran a war game in which Egypt moved three infantry divisions and 700 tanks across the Suez Canal in 16 hours. A top general dismissed the activity, saying he did not think “there is even a 10 percent chance they could pull [that] off.” The Arab soldier “lacks the qualities necessary for modern warfare,” he added, such as “a level of intelligence, adaptability, [and] fast reaction.”

THEORY-INDUCED BLINDNESS

According to a 2005 investigation by the Israeli newspaper Yedioth Ahronoth, sometime in 1969, a tall, impeccably dressed man walked into the Israeli embassy in London and asked to speak to a Mossad agent. “I want to work for you,” the man said. “I will give you information that you could only hope to obtain in your wildest dreams. I want money, a lot of money. And believe me, you will be happy to pay.”

The Israelis were, indeed, happy to pay, because the man who offered his services was Ashraf Marwan—Anwar Sadat’s presidential secretary and Nasser’s own son-in-law. The Yedioth Ahronoth investigation revealed that he received $24 million from the Israelis in today’s dollars. (To put that in perspective, the American known to have received the most money for spying was CIA double agent Aldrich Ames, who only received today’s equivalent of $4 million.)

Among other intelligence, Marwan gave his handlers a piece of information that seemed so important that Israeli military planners coined a Hebrew term to describe it: the Conceptzia, or “the concept.” This Conceptzia said that Egypt would not go to war until it acquired advanced Soviet fighter jets that could contend with the Israeli air force. Then, as now, on the chessboard of Israel’s military planning, the fighter jet with the Star of David on the fuselage was considered the largest piece: nearly 50 percent of Israel’s defense budget went to its air force. (In fact, between 1967 and 1972, Israel spent 10 percent of its entire GDP on its air force alone.) Sadat had made a deal with Moscow to acquire Soviet jets, but these were not due for delivery to Egypt until late 1974. And since it took at least a year to train pilots to fly them, in 1973, the Israelis figured they were safe for months to come.

Some Israeli officials worried about relying too heavily on Marwan or on their vaunted surveillance technology. One Israeli colonel, Yossi Langotsky, complained in mid-1973 to a young intelligence officer—Ehud Barak, a future Israeli prime minister—that he could not understand why most Israeli leaders “had the balls to say, ‘There will be war, there won’t be war.’ We all know how little information we have, [but] they piece it together into these elaborate theories.” Yet the state’s top officials felt the superiority of their intelligence gathering put a failsafe behind the possibility Marwan was mistaken. The chief of the Israeli military’s intelligence arm said that Israel’s spying capacity was “my insurance to tell me if there is a mistake in the Conceptzia.”

In the fall of 1973, King Hussein of Jordan, a state then in conflict with Egypt and Syria, met in secret with Israeli Prime Minister Golda Meir to warn that those countries were preparing to go to war; his warning went unheeded. Israeli intelligence had identified 45 “signs of war” to look out for, and over 30 of these existed in the field in early October 1973. But, stuck in the Conceptzia, Israeli military planners thought that most of these signs were consistent with military training. Marwan did not warn of the impending attack until the night before.

On Yom Kippur, Israeli intelligence found that Egyptian President Anwar Sadat had Conceptzias of his own. Sadat’s forces crossed the Suez Canal and began attacking Israeli troops in a bid to force Israel to withdraw from the Sinai Peninsula without a peace treaty. He was stopped, eventually, when Israeli troops surrounded his army. But his plan to shock the Israelis worked.

A BRIGHTER AFTERMATH

There are remarkable similarities between the dynamic that led to the Yom Kippur War and today. Hamas employed a tactic similar to Egypt’s by ramping up distracting training exercises, repeatedly moving fighters along the Israel-Gaza border and retreating over the past several months. Israel also severely underrated Hamas’s self-confidence, capacity to plan, and ability to evade surveillance. Ali Baraka, a senior Hamas official, has said that only a handful of Hamas’s senior leaders knew that on October 7, fighters would be ordered to blow through the border fence.

After the Israel-Hamas war ends, the Israelis will almost certainly convene a commission of inquiry. On November 18, 1973, Israel empaneled the Agranat Commission, headed by Supreme Court Chief Justice Shimon Agranat, to investigate the Yom Kippur War’s debacles. The commission heard from 90 witnesses and had investigators gather testimony from another 188. Its report blamed an overreliance on the Conceptzia and on purportedly “golden intelligence” from too few prized Egyptian sources.

Every subsequent commission of inquiry in Israel exists in the Agranat Commission’s shadow. The body established what Israelis now call a “culture of decapitation”—an instinct to respond to a failure with mass sackings and resignations in the hope that canning the people responsible will prevent the failure from recurring. A week after the commission issued its preliminary report on April 2, 1974, Meir announced her resignation. Israel’s defense minister, foreign minister, and finance minister were also replaced. Meir remarked that if there was any Israeli hero in the Yom Kippur War, it was David Elazar, the military’s chief of staff. Yet he, too, was fired.

The commission of inquiry that will follow today’s Israel-Hamas war may be even harsher on Israel’s current leadership. The Agranat Commission found that Israel ignored unmistakable signs of war; the upcoming commission may find the same. But Israel’s core misplaced assumptions were even more far-reaching than those they held in 1973, going to the very heart of the strategy that Israel has employed since withdrawing from Gaza almost 20 years ago.

Although no one believed that peace would come once Israel pulled out of Gaza, officials did think the border could be kept relatively quiet through deterrence—sharp responses to each attack—and economic incentives. In 2022, Israel sent 67,000 trucks of supplies into Gaza and issued permits to 20,000 Gazans to work in Israel. Israeli leaders believed Hamas would never risk losing such a degree of material support.

For a while, this premise appeared correct. Hamas and Israel traded rocket fire from time to time and fought several miniature wars. But the conflict seemed manageable and saved the Israeli taxpayer billions of dollars: Israel’s pre-2005 occupation of Gaza cost approximately $1.5 billion a year, or one percent of Israel’s mid-2000s GDP, just to support the Palestinian population, not counting the cost of garrisoning 24,000 troops to protect 8,000 Israeli settlers. The release of this fiscal burden undoubtedly played a large role in the near-quadrupling of the Israeli GDP between 2005 and today. With its forces no longer permanently stationed in Gaza, Israeli casualties also fell sharply.

But as the Hamas attack makes clear, Israel had not solved its security problems. Israeli officials may have concluded too soon that they had, effectively, neutralized the most severe risk from the enemy and, more important, misunderstood the motives of their adversary.

In testimony before the Winograd Commission—the Israeli inquiry into its 2006 war with Hezbollah—the former Israeli prime minister and Knesset member Shimon Peres said that war is a competition of blunders, and the biggest blunder of all is getting into a war in the first place. But in the aftermath of even the worst conflicts, there may be opportunities to better the places that got into war. After the Yom Kippur War, Egypt and Israel struck a peace agreement in which Israel returned the Sinai Peninsula and Egypt formally recognized Israel’s existence.

Some similar opportunities might exist for peace today. Somebody will have to assume authority in Gaza if an Israeli operation there deposes Hamas. Perhaps a multinational Arab force, spearheaded by Egypt and Saudi Arabia, could take responsibility for security and help restore the Ramallah-based Palestinian Authority to Gaza, incentivized by American security guarantees and permission to enrich uranium for civilian use. The story of the Yom Kippur War suggests that when so many old assumptions are upended, harmful ones—such as the assumption that there can be no two-state solution or no effective governance in the Palestinian territories—can be changed, too.