When Hamas invaded Israel on the morning of October 7, 2023, the country was unprepared for the onslaught. Before the Israeli military could regain control, Hamas fighters had killed around 1,200 people and took about 250 more hostage—approximately 50 of whom are still being held, 20 of which are still thought to be alive in captivity almost two years later. For a country on constant alert to threats from its neighbors on all sides, how was Israel's military caught by surprise? That's the question former editor-in-chief of The Jerusalem Post Yaakov Katz and military and defense journalist Amir Bohbot interrogate in their new book, While Israel Slept: How Hamas Surprised the Most Powerful Military in the Middle East. Their book offers an analysis of the massive failure, with the goal of highlighting lessons that should be learned going forward. In this exclusive excerpt, Bohbot and Katz revisit the night before the attack, examining how Israeli intelligence could have prevented the invasion.
On Friday afternoon, October 6, 2023, while most IDF commanders were preparing for the Sukkot holiday weekend, IDF chief Herzi Halevi convened a group of senior officers on the military's secure phone line to review what was expected that weekend.
A former head of the Southern Command and Aman, the IDF's intelligence body, Halevi was an officer of the big army but also of the special forces, well versed in the difference between the two and how to get the best out of a large force or just a few good men. He also knew the importance of having intelligence agencies work together. As head of Aman from 2014 to 2018, he oversaw the signing of a memorandum of understanding between that agency and Shin Bet that clarified responsibility over different areas as well as the allocation of resources.
On the phone call that afternoon, the consensus was that nothing was out of the ordinary. Intelligence officials reported no unusual activity, save for the attempted smuggling of an advanced anti-tank missile system from Sinai into Gaza and the ongoing effort to thwart it. Engineering forces from the IDF's Gaza Division had placed concrete blocks to protect the road to Kibbutz Nahal Oz from anti-tank missile fire—a precaution that would soon prove tragically inadequate as, the next day, October 7, terrorists simply hopped over the blocks with amazing ease.
By the time the call finished, and Halevi did not yet know this, Brigadier General Yossi Sariel, commander of Unit 8200—the IDF's premier signal-collection unit revered within Israel and beyond for intelligence capabilities that rivaled those of America's NSA—had received some disturbing news: a system that monitors activities in the Gaza Strip had crashed.
This was not just another system (its official name remains classified). It was designed to identify anomalies in Gaza, using advanced algorithms to detect anything out of the ordinary in the crowded Palestinian enclave. Apparently, it had crashed a number of times over the previous 24 hours, and efforts were underway to get it back up and running. Personnel had been scrambled back to base from their holiday breaks, but in the meantime, the system, crucial for detecting possible attacks, remained down. It was also a problem for Shin Bet, which has access to the alerts that the system gives off as well as to another system through which all intelligence collected by Israel's services regularly flows.
On the one hand, the system crashing was a red flag that something strange was happening. On the other hand, it was a delicate system that often crashed. Nevertheless, some senior defense officials, a full year after October 7, suspected that the malfunctions were not a coincidence but rather the result of a sophisticated cyberattack that included intentional power outages to blind Israeli surveillance.
While the IDF was continuing with its holiday, at 10:00 p.m., Shin Bet received a troubling alert on one of its own systems. Dozens of senior Hamas military operatives in Gaza had activated mobile devices with Israeli SIM cards, causing a dramatic spike in call traffic. Shin Bet, long aware of Hamas' tactic of using Israeli SIM cards to evade detection, understood the potential threat and passed on the information to the IDF Southern Command. The fear was that Hamas was getting ready for an attack and had activated the SIM cards so that the terrorists, being sent to breach the border, would have a way to communicate with commanders in Gaza even after crossing into Israel.
The Shin Bet commanders in charge of the south called Major General Yaron Finkelman, head of the Southern Command, while he was on vacation with his family up in the north. Finkelman had taken up the mantle of the Southern Command three months earlier and was still learning the ropes. He decided not to take any chances; cutting his weekend break short, he began the drive back to Beersheba in the south, the location of the command's headquarters.
On the one hand, the activation of the SIM cards was strange. The phones were all on and were not shutting off. On the other hand, this was not the first time that they had been turned on. Months after the attacks, Shin Bet presented findings from its initial investigation into the night of October 6 and revealed that on Thursday, October 5, some of the SIM cards had also been turned on, but only for a short period of time before quickly being turned off. In addition, the Shin Bet system showed that the same exact SIM cards had been activated exactly one year earlier on October 7, 2022, and nothing had happened. Shin Bet officials figured that the 2023 activation of the SIM cards was likely an annual test, even though there were two significant differences from the 2022 occurrence—the number of SIMs was much greater, and the phones were scattered across the Gaza Strip and not located in one specific area.
Halevi received a general update about the SIM cards without the complete backstory of how it might be an annual test and was ordered to absorb the information but not to spread it too wide and jeopardize the source. Officers were instructed not to write anything down and not to leave a trace. This cautious approach effectively tied the hands of the Southern Command and the Gaza Division, preventing them from reinforcing their positions or making defensive moves that might tip off Hamas that Israel was aware that something was happening and thus preventing the assault.
In hindsight, the chief of staff's approach might have been overly cautious. Had he not tied the Gaza Division's hands, it is possible that deploying additional tanks along the border or dispatching two more attack helicopters could have been enough to signal to Hamas that Israel was aware that the group was planning a border attack. It might have been enough to get Hamas to reconsider its plans for the following morning.
It was a tense night. Most of the officers read into the intelligence went to sleep slightly more anxious than they were hours earlier but no one thought that anything big was about to happen. It wasn't that the IDF did not have forces deployed along the border. Yes, it was a holiday, and yes, it was Saturday, but the IDF was always on alert along a volatile border like Gaza. Special observation posts along the border were manned 24 hours a day, and nearby air force assets were ready to scramble with just one word.
Shin Bet chief Ronen Bar was trying to get some sleep at his home in a Tel Aviv suburb when his assistant called at 2:00 a.m. on October 7. A 30-year veteran of Israel's counterterrorism agency, Bar was used to calls in the middle of the night, but this one was different. The information was vague, yet ominous. "There is an unclear preparation by Hamas for something," his assistant told him.
In addition to the SIM card alert four hours earlier, Hamas operatives were apparently preparing an underground tunnel complex that top field commanders descended into in the event of an emergency. Bar asked the assistant if he knew if the commanders were in the bunker complex.
"Not yet," he answered.
Based on the initial intelligence, it seemed that the preparation of the complex was part of a Hamas training exercise, one of many that the group had carried out in the previous year.
Nevertheless, Bar couldn't shake the feeling that something was amiss. Despite reassurances that the bunker preparations were likely nothing unique, he decided to head to Shin Bet headquarters in north Tel Aviv to dig deeper and be ready. Just in case, he told himself.
Bar, who sports a crew cut and gray stubble, started his military career as a fighter in the Sayeret Matkal, Israel's counterterrorism agency, participating in numerous covert operations.
Now his instincts were on high alert. On his way to the office, he sent a message summoning a number of top Shin Bet officials who were responsible for Gaza and the West Bank to a conference call at 3:30 a.m. Despite intelligence indicating that what was happening was most likely a military exercise, Bar feared a more sinister plot—perhaps a Hamas attempt to cross the border and try to kidnap a few soldiers. The greater fear on his mind was that if this happened, Palestinian terrorist groups in the West Bank as well as Hezbollah and might also get involved.
The head of Shin Bet was informed that the intelligence had been passed on to the Southern Command and the Gaza Division. They could now check their systems and sources to see if they could find anything else to complete the puzzle.
As Bar made his way to the office, Shin Bet analysts were busy poring over the information they had to see if there was anything fresh. One mentioned some intelligence that had just been received in which it was mentioned that Hamas was removing the protective fabric from some of its rocket launch pits, a step that preceded a rocket attack. An hour later, though, Shin Bet received new intelligence in which Hamas was insisting that removal of the fabric was merely part of a drill.
In hindsight, it became clear that even more intelligence got "stuck" within Aman and never reached the top IDF brass or Shin Bet. One important detail, for example, was that in the days leading up to October 7, there was a surge in Hamas communication traffic—phone calls and messaging more than doubled. No one brought this crucial detail, along with other pieces of information, to the attention of Halevi, Finkelman, or the head of the IDF's Operations Directorate, Major General Oded Basiuk, a veteran tank commander, at any point throughout the night.
The clock was ticking, but there were still no changes on the Israeli side.
From While Israel Slept: How Hamas Surprised the Most Powerful Military in the Middle East by Yaakov Katz and Amir Bohbot. Copyright © 2025 by the author and reprinted by permission of St. Martin's Publishing Group.
