How Was Israel Caught Off-Guard?


Hamas’ Oct. 7 attacks did not happen out of the blue. They were preceded by years of bitter conflict, ever since the group consolidated its control of the Gaza Strip in 2007. Months later, it remains deeply puzzling how Israel was caught so woefully unprepared.

Conventional explanations advanced over the years by numerous scholars and practitioners analyzing similar historical fiascoes provide part of the answer. The surprise can be attributed to abundant noise, deception, wishful thinking, groupthink, and failure of imagination. Nevertheless, careful analysis of the case at hand highlights several additional factors. The degree of surprise reflected an intelligence-collection shortfall on Hamas’ intentions. There was an over-reliance on warning systems, a misguided policy and military attitude toward Hamas, and a toxic relationship between Israel’s top leadership and its defense and intelligence establishment. These factors both distracted the establishment and systematically discouraged a confrontation with Hamas. Taken together, these factors underscore the need for countries to recalibrate their expectations regarding warnings of potential attacks and to put a newfound emphasis on readiness rather than prediction.



Roberta Wohlstetter’s pioneering study of the Pearl Harbor disaster triggered a voluminous literature seeking to understand how surprise attacks happen. Wohlstetter drew attention to signal-to-noise ratios, as well as to the bias introduced by their analysis in hindsight. Subsequently, scholars examining similar historical cases — notably the 1941 German attack on the Soviet Union, the Egyptian–Syrian October 1973 attack on Israel, and 9/11 — further drew attention to the role of deception and diverse psychological barriers, biases, and cognitive pathologies. Other authors were inspired by related academic contributions on the role of flawed decision-making dynamics (such as groupthink) in distorting awareness and commensurate responses. A related literature has examined the contribution of institutional and irrational factors, as well as misleading human heuristics for dealing with uncertainty and complexity, associated with estimates of probability. In short, scholars commonly trace surprises back to this set of rather common and persistent psychological, institutional, and political roots, even if they typically differ in the relative weight they assign to this or that factor in specific cases.

However, when applied to the events of Oct. 7, these explanations manifest two problems that have also plagued many earlier studies of surprise attacks. First, they build upon the contentious premise that the quality of the advance warning available to the victim was more than adequate to anticipate the attack. This premise is heavily influenced by the lack of a comparative benchmark of warning indicators and thus highly susceptible to hindsight bias. Second, by focusing on one observable outcome — a glaring disaster in the face of a bold adversarial action — they generally fail to disaggregate two analytically distinct phenomena: The failure of intelligence to anticipate and warn of an impending attack, and the inadequate military preparations in the face of an unanticipated threat. Israel not only failed to anticipate such a bold Hamas assault, but also lacked adequate plans, forces, and levels of readiness to effectively respond to such a scenario.

The 10/7 Intelligence Failure

Israeli intelligence contributed to this by failing to foresee that such a large, sophisticated onslaught was viable or coming, notwithstanding multiple tactical and operational signs accumulating over time. When the internal security service (Shabak) finally caught on to some disconcerting signals from Gaza hours before the attack started, its head apparently interpreted these as suggesting merely a localized kidnapping attempt, ordering only a modest effort to confront it.

On the face of it, this in itself remains shocking. The Hamas threat has been high on Israel’s radar since 2007. An extensive intelligence apparatus was tasked with monitoring the group’s activities and assessing its intentions. Additionally, the Israeli intelligence community, badly shaken by the surprise attack of 1973, was nominally hypersensitive to the prospects of another one. And a sizable Israeli military force was routinely deployed next to the Gaza Strip, tasked with protecting the population and responding to Hamas’ almost constant provocations and periodic attacks.

Furthermore, Hamas’ extensive, methodical planning and preparations for the attack and its intensifying dress rehearsals took place in plain sight of Israeli observers. These were spotted in real time and widely reported, but they were mostly interpreted as intensifying training exercises rather than an attack in the making. It is only with the benefit of hindsight that these warning indicators appear clairvoyant, presaging concrete attack preparations — whereas at the time all they revealed was the acquisition of the capability to attack, or perhaps an indication (as has often been the case with Hamas) of politically motivated saber rattling.

The nature of the Israeli–Hamas conflict was such that Israeli intelligence was put in the unenviable position of being expected first and foremost to assess Hamas’ intentions rather than its capabilities. While Israeli intelligence did correctly estimate earlier in the year the probability of war with one or more Arab parties to meaningfully rise in the course of 2023, prior to Oct. 7, Israeli intelligence never managed to obtain a “smoking gun” of Hamas leadership’s intentions to carry out a bold attack, let alone its timing. The consequences of this failure were exacerbated by the supreme confidence of the intelligence chiefs — as well as the consumers of their intelligence — that they would in fact obtain concrete early warning ahead of any sizable attack. This was further reinforced by their successful track record in discovering Hamas’ strategic and operational secrets and correctly estimating its behavior.

Remarkably, some intelligence officials are reported to have concluded in the months preceding the attack that the quality of their coverage of Hamas’ intentions was slipping and required bolstering. This assessment, however, did not fundamentally shake the widespread expectation that a Hamas decision to deviate from its past behavior and undertake bolder action than mere skirmishes along the border would not go undetected. This set the stage for a colossal intelligence failure when tightened Hamas compartmentalization, a thicker veil of secrecy on its plans, and perhaps some deliberate deception over its intentions succeeded in depriving Israel of explicit signals presaging an attack.

Absent explicit warning indicators, all Israeli intelligence could do was offer estimates of Hamas’ calculus and intentions, which in retrospect seem badly misguided. Apparently, they were led astray by some combination of five factors.

The first was an over-reliance on their formidable technical intelligence apparatus — primarily signals intelligence — to offset the collection difficulty associated with prying open, through human intelligence, the innermost secrets of Hamas’ top leaders. As the CIA director recently observed, human intelligence is especially critical for assessing a leader’s intent, yet exceedingly difficult to obtain in secretive and tight-knit leadership circles. The second was cultural arrogance, leading the Israeli establishment to grossly underestimate the capacity and audacity of Hamas. The group was viewed as a mere second-tier terrorist or paramilitary organization (certainly in comparison to Hizballah), hardly capable of mounting a sophisticated low-tech attack against the vastly superior Israel Defense Forces. The third was institutional chauvinism. This manifested itself in systematic undervaluation of warnings sounded by junior women in various observation and collection units, and perhaps reflecting that fact that women are hugely underrepresented in the higher echelons of Israeli intelligence. The fourth was bandwidth limitations on Israeli intelligence, which was simultaneously focused on disconcerting developments and operational requirements in the West Bank, Lebanon, Syria, and Iran. Finally, Hamas deception may have played a role, as perhaps did the crying wolf syndrome; Israeli intelligence had previously warned of a possible attack on April 23 that Hamas then called off, apparently realizing that its plans had been compromised.

The Causes of Unpreparedness

The Israeli military’s standing forces and contingency plans proved woefully inadequate to effectively contain and subsequently respond to the 10/7 Hamas attack. With the partial exception of the internal security head who responded to non-specific but alarming signals hours before the attack by dispatching to the area a small counter-terrorism unit, Israeli units on the ground as well higher echelon commanders further afield were caught completely off-guard, woefully uninformed about the situation, and utterly unprepared to effectively address such a chaotic scene. For the better part of a day, the military’s reaction to Hamas’ atrocities was largely improvised, and by the time the military and security forces were able to regroup, much of the damage had already been done.

What accounts for this lack of preparedness? One factor was clearly Hamas’ choice to time the attack on the Sabbath, when many active-duty units are typically on home leave (reminiscent of the Egyptian–Syrian practice on Yom Kippur in October 1973). Perhaps more critical, though, were three additional factors. First was a deeply misplaced trust in the efficacy of Israeli deterrence. This was largely predicated on the Israeli military’s overwhelming overall superiority and the virtues of the billion-dollar, high-tech fence Israel has erected along its border with Gaza, which was believed to present a formidable barrier both above and below the ground.

Over time, the reliance on the efficacy of the fence induced complacency. This led to the decision to reclaim the rifles that Israel had originally issued to the emergency security teams in the border settlements and reassign standing military forces toward supposedly more pressing hot spots, a trend that had intensified in the days immediately preceding the attacks. Second, a measure of cultural arrogance, conceptual rigidity, and groupthink prevented Israeli officials from recognizing the calculus guiding the Hamas leadership. Strikingly, all the way up to Oct. 7, Israeli policymakers sustained their belief that Hamas’ top leadership was not only deterred from escalation but also heavily motivated by self-preservation and greed. Thus, they assumed that Israel could use small gestures, ranging from work permits for Gazans in Israel to acquiescence in regular Qatari cash infusions, to preserve the status quo. Finally, besides general preoccupation with other (potentially graver threats) there was a more immediate distraction caused by the rapidly deteriorating situation on the West Bank, a threat that was especially politically sensitive for the government of Benjamin Netanyahu, which resulted in the gradual redeployment of units away from the vicinity of Gaza to beef up the presence in the West Bank.

The Intelligence–Policy Nexus  

These failures were compounded by trouble at the intelligence–policy nexus. First, relations between the prime minster, the defense minister (who he unsuccessfully tried to fire), and the security establishment had grown especially toxic after they repeatedly warned the prime minister earlier in 2023 about the adverse impact on Israeli security of his extreme right-wing government’s policies and the growing prospects of war as a result. Netanyahu resented their repeated warnings about the growing internal divide within Israeli society unleashed by his policies and the way these influenced foes’ perceptions of Israeli vulnerability.

Second, Netanyahu was less receptive to warnings about Hamas because he saw the group’s hostility toward Israel and rivalry with the Palestinian Authority as helpful bulwarks against external pressures to negotiate the formation of a Palestinian state. This perception of expediency manifested itself in his consistent decisions to try to “bribe” Hamas and resist repeated calls to check its militarization through a combination of sanctions and decisive military action. Netanyahu’s preference for seeking some form of modus vivendi with Hamas probably also factored in the formidable risks associated with launching a comprehensive preemptive Israeli military campaign against them, as well as his previous success in managing tensions with the group.


What lessons do these failures offer for other countries? Western countries in particular should be wary of an over-reliance on technological prowess to avoid human or political sacrifice. Technological solutions can work astoundingly well, as is the case with the Israeli missile defense systems or, initially, the Gaza fence and Israeli signals intelligence. However, they are rarely a panacea. Worse still, their very success can become self-defeating by breeding complacency as adversaries work to counter or bypass them. Governments should consistently subject to critical review (ideally drawing on ad hoc external experts) their threat assessment of the capabilities and intentions of supposedly second-rate players, allowing for the possibility that the combination of single-minded determination, the harvesting of ever more affordable commercial dual-use technology, and extensive foreign assistance could make them into very potent threat actors. Witness not only the al-Qaeda 9/11 and Hamas 10/7 attacks, but also the remarkable sophistication repeatedly demonstrated by the Houthis.

Another lesson here lies in the risks associated with pinning excessive hope on one of the most common (and intuitively appealing) recommendations for avoiding strategic surprise —promoting institutional pluralism in assessments and encouraging devil’s advocacy. Israeli intelligence did this in response to the trauma of the 1973 war, implementing the recommendations of the Agranat Commission of Inquiry that followed. Yet the practice of devil’s advocacy atrophied over time, while pluralism proved insufficient. The combination of routinized practice, groupthink, and policy pressure largely defeated its utility. Recent evidence suggests that last September the department in Israeli’s military intelligence that was supposed to play a devil’s advocate role did in fact warn that Hamas was becoming more conflict prone, but these warnings were dismissed.

This leads to the biggest takeaway. In final analysis, governments should periodically revisit their precise expectations of warnings from the intelligence community to ascertain that these are not only realistic but also adjusted to changing circumstances and policy priorities. They should recognize the ever-present risks of relying on intelligence at the expense of planning for unexpected scenarios. Most policymakers would rather not worry about threats that their intelligence services view as unlikely. Prediction and estimates should not supplant preparedness, as they will inevitably lead to occasional failure. Some, perhaps subconsciously, are eager to have intelligence as a convenient scapegoat should debacles occur. But it falls to policymakers to realize that intelligence is always imperfect. For this reason, prediction should never take the place of preparedness.



Ariel (Eli) Levite is a senior Fellow at the Carnegie Endowment for International Peace and author of Intelligence and Strategic Surprises.

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