It was 3 a.m. on Oct. 7, and Ronen Bar, the head of Israel’s domestic security service, still could not determine if what he was seeing was just another Hamas military exercise.
At the headquarters of his service, Shin Bet, officials had spent hours monitoring Hamas activity in the Gaza Strip, which was unusually active for the middle of the night. Israeli intelligence and national security officials, who had convinced themselves that Hamas had no interest in going to war, initially assumed it was just a nighttime exercise.
Their judgment that night might have been different had they been listening to traffic on the hand-held radios of Hamas militants. But Unit 8200, Israel’s signals intelligence agency, had stopped eavesdropping on those networks a year earlier because they saw it as a waste of effort.
As time passed that night, Mr. Bar thought that Hamas might attempt a small-scale assault. He discussed his concerns with Israel’s top generals and ordered the “Tequila” team — a group of elite counterterrorism forces — to deploy to Israel’s southern border.
Until nearly the start of the attack, nobody believed the situation was serious enough to wake up Prime Minister Benjamin Netanyahu, according to three Israeli defense officials.
Within hours, the Tequila troops were embroiled in a battle with thousands of Hamas gunmen who penetrated Israel’s vaunted border fence, sped in trucks and on motorbikes into southern Israel and attacked villages and military bases.
The most powerful military force in the Middle East had not only completely underestimated the magnitude of the attack, it had totally failed in its intelligence-gathering efforts, mostly due to hubris and the mistaken assumption that Hamas was a threat contained.
Despite Israel’s sophisticated technological prowess in espionage, Hamas gunmen had undergone extensive training for the assault, virtually undetected for at least a year. The fighters, who were divided into different units with specific goals, had meticulous information on Israel’s military bases and the layout of kibbutzim.
The country’s once invincible sense of security was shattered.
More than 1,400 people were killed, including many women, children and old people who were murdered systematically and brutally. Hundreds are held hostage or are still missing. Israel has responded with a ferocious bombardment campaign on Gaza, killing more than 8,000 Palestinians and wounding thousands more, according to the Hamas-run health ministry. The Israeli military on Sunday signaled a heavier assault on Gaza, saying it had expanded its ground incursion overnight.
Israeli officials have promised a full investigation into what went wrong.
Even before that inquiry, it is clear the attacks were possible because of a cascade of failures over recent years — not hours, days or weeks. A New York Times examination, based on dozens of interviews with Israeli, Arab, European and American officials, as well as a review of Israeli government documents and evidence collected since the Oct. 7 raid, shows that:
Israeli security officials spent months trying to warn Mr. Netanyahu that the political turmoil caused by his domestic policies was weakening the country’s security and emboldening Israel’s enemies. The prime minister continued to push those policies. On one day in July he even refused to meet a senior general who came to deliver a threat warning based on classified intelligence, according to Israeli officials.
Israeli officials misjudged the threat posed by Hamas for years, and more critically in the run-up to the attack. The official assessment of Israeli military intelligence and the National Security Council since May 2021 was that Hamas had no interest in launching an attack from Gaza that might invite a devastating response from Israel, according to five people familiar with the assessments who spoke on the condition of anonymity to discuss sensitive details. Instead, Israeli intelligence assessed that Hamas was trying to foment violence against Israelis in the West Bank, which is controlled by its rival, the Palestinian Authority.
The belief by Mr. Netanyahu and top Israeli security officials that Iran and Hezbollah, its most powerful proxy force, presented the gravest threat to Israel diverted attention and resources away from countering Hamas. In late September, senior Israeli officials told The Times they were concerned that Israel might be attacked in the coming weeks or months on several fronts by Iran-backed militia groups, but made no mention of Hamas initiating a war with Israel from the Gaza Strip.
American spy agencies in recent years had largely stopped collecting intelligence on Hamas and its plans, believing the group was a regional threat that Israel was managing.
Overall, arrogance among Israeli political and security officials convinced them that the country’s military and technological superiority to Hamas would keep the terrorist group in check.
“They were able to trick our collection, our analysis, our conclusions and our strategic understanding,” Eyal Hulata, Israel’s national security adviser from 2021 until early this year, said during a discussion last week in Washington sponsored by the Foundation for Defense of Democracies, a think tank.
“I don’t think there was anyone who was involved with affairs with Gaza that shouldn’t ask themselves how and where they were also part of this massive failure,” he added.
Many senior officials have accepted responsibility, but Mr. Netanyahu has not. At 1 a.m. Sunday in Israel, after his office was asked for comment on this article, he posted a message on X, formerly Twitter, that repeated remarks he made to The New York Times and blamed the military and intelligence services for failing to provide him with any warning on Hamas.
“Under no circumstances and at no stage was Prime Minister Netanyahu warned of war intentions on the part of Hamas,” the post read in Hebrew. “On the contrary, the assessment of the entire security echelon, including the head of military intelligence and the head of Shin Bet, was that Hamas was deterred and was seeking an arrangement.”
In the resulting furor, Benny Gantz, a member of his war cabinet, publicly rebuked Mr. Netanyahu, saying that “leadership means displaying responsibility,” and urged the prime minister to retract the post. It was later deleted, and Mr. Netanyahu apologized in a new one.
On Sunday, Shin Bet promised a thorough investigation after the war. The I.D.F. declined to comment.
The last time Israelis’ collective belief in their country’s security was similarly devastated was 50 years earlier, at the start of the Yom Kippur War, when Israel was caught off guard by an assault by Egyptian and Syrian forces. In an echo of that attack, Hamas succeeded because Israeli officials made many of the same mistakes that were made in 1973.
The Yom Kippur War was “a classic example of how intelligence fails when the policy and intelligence communities build a feedback loop that reinforces their prejudices and blinds them to changes in the threat environment,” Bruce Riedel, a former top Middle East analyst at the Central Intelligence Agency, wrote in a 2017 research paper about the 1973 war.
In an interview this month, Mr. Riedel said that Mr. Netanyahu was reaping the consequences of focusing on Iran as the existential threat to Israel while largely ignoring an enemy in his backyard.
“Bibi’s message to Israelis has been that the real threat is Iran,” he said, using Mr. Netanyahu’s nickname. “That with the occupation of the West Bank and the siege of Gaza, the Palestinian issue is no longer a threat to Israel’s security. All of those assumptions were shattered on Oct. 7.”
On July 24, two senior Israeli generals arrived at the Knesset, Israel’s parliament, to deliver urgent warnings to Israeli lawmakers, according to three Israeli defense officials.
The Knesset was scheduled that day to give final approval to one of Mr. Netanyahu’s attempts to curb the power of Israel’s judiciary — an effort that had convulsed Israeli society, ignited massive street protests and led to large-scale resignations from the military reserves.
A growing portion of the Air Force’s operational pilots was threatening to refuse to report to duty if the legislation passed.
In the briefcase of one of the generals, Aharon Haliva, the head of the Israeli Defense Forces’ Military Intelligence Directorate, were highly classified documents detailing a judgment by intelligence officials that the political turmoil was emboldening Israel’s enemies. One document stated that the leaders of what Israeli officials call the “axis of resistance” — Iran, Syria, Hamas, Hezbollah and Palestinian Islamic Jihad — believed this was a moment of Israeli weakness and a time to strike.
Hezbollah’s leader, Hassan Nasrallah, according to one of the documents, said that it was necessary to prepare for a major war.
General Haliva was ready to tell the coalition leaders that the political turmoil was creating an opportunity for Israel’s enemies to attack, particularly if there were more resignations in the military. Only two members of the Knesset came to hear his briefing.
The legislation passed overwhelmingly.
Separately, Gen. Herzi Halevi, the military’s chief of staff, tried to deliver the same warnings to Mr. Netanyahu. The prime minister refused to meet him, the officials said. Mr. Netanyahu’s office did not respond to a request for comment about this meeting.
The generals’ warnings were in large part based on a series of provocations on Israel’s northern border.
In February and March, Hezbollah had sent explosive-laden drones toward Israeli gas rigs. In March, a militant climbed over the border fence from Lebanon into Israel, carrying several powerful bombs, weapons, phones and an electric bike on which he traveled to a major northern intersection. He then used a powerful charge, apparently trying to blow up a bus.
On May 21, Hezbollah staged for apparently the first time war games at one of its training sites in Aaramta in south Lebanon. Hezbollah launched rockets and flew drones that dropped explosives on a simulated Israeli settlement.
Israeli officials believed that Hezbollah was leading the planning for a coordinated attack against Israel, but not one that would prompt an all-out war.
The officials’ concerns grew through August and September, and General Halevi went public with his concerns.
“We must be more prepared than ever for a multi-arena and extensive military conflict,” he said at a military ceremony on Sept. 11, just weeks before the attack.
Mr. Netanyahu’s allies went on Israeli television and condemned General Halevi for sowing panic.
In a series of meetings, Shin Bet gave similar warnings to senior Israeli officials as General Halevi. Eventually, Mr. Bar also went public.
“From the investigations we are doing we can say today that the political instability and the growing division are a shot of encouragement to the countries of the axis of evil, the terrorist organizations and the individual threats,” Mr. Bar said in a speech.
Mr. Netanyahu’s government also ignored warnings from Israel’s neighbors. As the custodian of Muslim holy sites in Jerusalem, Jordan has traditionally been an important mediator between Palestinians and Israel’s government on the Aqsa Mosque compound, the third most holy site in Islam. The mosque compound has seen repeated raids by Israeli forces over the years, and Hamas has said that it launched this month’s attack in part as retaliation for those acts.
But Jordan found that when Mr. Netanyahu formed a government late last year, the most far right in recent history, it was less receptive to their warnings that the incidents at the Aqsa Mosque compound was stirring up sentiment inside Palestinian territories that could boil over into violence, according to two Arab officials with knowledge of the relationship.
The Wrong Focus
While security and intelligence officials were right about a coming attack, their intense focus on Hezbollah and Iran had a tragic effect: Far less attention was paid to the threats from Gaza. Since Israel’s withdrawal in 2005 and Hamas’s evolution from a purely guerrilla organization into the governing power of Gaza in 2007, Hamas had only periodic skirmishes with the Israeli military.
Under four different prime ministers, Israel repeatedly decided that reoccupying Gaza and crushing Hamas would cost too many lives and do too much damage to Israel’s international reputation.
Israel knew that Hamas, which Iran supports with funding, training and weapons, was growing stronger over time. But officials thought they could contain Hamas with an extensive network of human spies, sophisticated surveillance tools that would deliver early warnings of an attack and border fortifications to deter a Hamas ground assault. They also relied on the Iron Dome air defense system for intercepting rockets and missiles launched from Gaza.
The strategy, confirmed by multiple Israeli officials, bore some fruit. Over the years, Israel’s investment in penetrating Hamas’s inner circle in Gaza allowed Israel to uncover the group’s attack plans and occasionally led to assassinations of Hamas leaders.
Publicly, Mr. Netanyahu used blunt rhetoric about Hamas. His election slogan in 2008 was “Strong Against Hamas,” and in one campaign video at the time he pledged: “We will not stop the I.D.F. We will finish the job. We will topple the terror regime of Hamas.”
Over time, however, he came to see Hamas as a way to balance power against the Palestinian Authority, which has administrative control over the West Bank and has long sought a peace agreement in Israel in exchange for a Palestinian state.
Mr. Netanyahu told aides over the years that a feeble Palestinian Authority lowered the pressure on him to make concessions to Palestinians in negotiations, according to several former Israeli officials and people close to Mr. Netanyahu. An official in Mr. Netanyahu’s office, who spoke on the condition of anonymity, denied this had been the prime minister’s policy.
But there is no question that Israeli officials viewed Hamas as a regional threat, not a global terrorist organization like Hezbollah or the Islamic State. This view was shared in Washington, and American intelligence agencies dedicated few resources to collecting information on the group.
Some parts of the American government even believed that Hamas operatives could be recruited as sources of information about terrorist groups considered more urgent priorities in Washington.
Jonathan Schanzer, a former Treasury Department official and now the senior vice president for research at the Foundation for Defense of Democracies, recalled a meeting he had in 2015 with American intelligence and law enforcement officials about suspected Hamas operatives inside the United States.
During the meeting, he recalled, the officials told him they were trying to turn the Hamas operatives into “assets” in the fight against the Islamic State.
The Invincibility of the Wall
Israeli officials firmly believed that “The Barrier” — a nearly 40-mile-long reinforced concrete wall above and below ground, completed in 2021 — would hermetically seal off Gaza. There was also a surveillance system at the border based almost exclusively on cameras, sensors and remote-operated “sight-shooter” systems, four senior Israeli military officers told The Times.
Senior Israeli military officials believed that the combination of remote surveillance and machine-gun systems with the formidable wall would make it almost impossible to infiltrate Israel, and thus reduce the need for a large number of soldiers to be stationed at the bases.
But Hamas’s attack exposed the fragility of that technology. The group used explosive drones that damaged the cellular antennas and the remote firing systems that protected the fence between Gaza and Israel.
To get around Israel’s powerful surveillance technology, Hamas fighters also appeared to enforce strict discipline among the group’s ranks to not discuss its activities on mobile phones. This allowed them to pull off the attack without detection, one European official said.
The group most likely divided its fighters into smaller cells, each probably only trained for a specific objective. That way, the rank and file did not understand the scale of the attacks they were preparing for and could not give away the operation if caught, a European official said, based on his analysis of how the attack unfolded and from the videos the group disseminated from the operation.
Hamas may have learned such operational discipline from Hezbollah, which has long confused Israeli forces on the battlefield by dividing its fighters into smaller units of friends or relatives, according to Lebanese officials with ties to the group. If the fighters speak openly on cellphones to coordinate military operations, Lebanese officials with ties to the group said, part of their code is to speak in childhood memories — for example, asking to meet up in a field where they once played together.
Hamas claimed that 35 drones took part in the opening strike, including the Zawari, an explosive-laden drone.
“We started receiving messages that there was a raid on every reporting line,” testified one soldier, who was at the Gaza Division base on the day of the invasion, in a conversation with the “Hamakom Hachi Ham Bagehinom” (“The Hottest Place in Hell”) website.
“On every reporting line, swarms of terrorists were coming in,” the soldier added. “The forces did not have time to come and stop it. There were swarms of terrorists, something psychotic, and we were simply told that our only choice was to take our feet and flee for our lives.”
In a conversation with military investigators two weeks after the attack, soldiers who survived the assault testified that the Hamas training was so precise that they damaged a row of cameras and communication systems so that “all our screens turned off in almost the exact same second.” The result of all this was a near total blindness on the morning of the attack.
After the fighting had stopped, Israeli soldiers found hand-held radios on the dead bodies of some of the Hamas militants — the same radios that Israeli intelligence officials had decided a year ago were no longer worth monitoring.
Farnaz Fassihi contributed reporting from New York, and Eileen Sullivan from Washington.