Executive Summary
The October 7, 2023, Hamas attack and ensuing multi-front war exposed critical failures in Israel’s security doctrine, particularly in early warning, deterrence, and defense. Israel’s traditional four pillars—early warning, deterrence, decisive victory, and defense—proved inadequate against hybrid terror armies operating from urban and underground environments. To address these shortcomings, Israel must revise its security concept by adding a fifth pillar: prevention and suppression of enemy force build-up. This requires stronger intelligence coordination, expanded forces, and sustained cooperation with the United States to maintain freedom of action. Deterrence must account for ideologically driven adversaries, while defense strategies must ensure truly defensible borders. A decisive victory remains essential but must align with strategic and moral considerations. The updated doctrine should prepare Israel to operate across multiple arenas, strengthen resilience, and secure its long-term regional stability and survival.
Hamas’s murderous terrorist attack on October 7, 2023, and the prolonged war Israel has since waged across eight arenas, shook Israel’s security concept and require a review of its existing principles and the formulation of a new concept. Above all, they demonstrated how Israel’s security and very existence are challenged by many of its neighbors, and how essential it is that the security concept take this fact into account, along with efforts to build a regional architecture that strengthens actors willing to maintain peaceful relations with Israel and to reduce, as far as possible, the intensity of hatred and hostility (de-radicalization).
Until October 7, the security concept rested on an analysis of Israel’s relative military, human, technological, demographic, geographic, diplomatic, and economic advantages and disadvantages in relation to its environment. It was built on four pillars: early warning, deterrence, decisive victory, and defense. A series of principles was designed to ensure those pillars were realized. These included a people’s army based on compulsory service and a large reserve force; air and intelligence dominance and superiority; preservation and expansion of the qualitative edge; a commitment to defend ourselves by ourselves while maintaining strategic and operational cooperation with the United States grounded in shared values and interests; shifting the fighting to enemy territory; developing indigenous technological solutions such as missile defense; continuous learning; preventing enemy nuclearization; responding to any harm to Israeli interests; preventing force build-up through the campaign between wars (MABAM); home-front resilience; adherence to the laws of armed conflict and IDF values; and preserving international legitimacy.
On October 7, Israel failed in warning, deterrence, and defense. Despite impressive battlefield achievements, it did not succeed in defeating Hamas in Gaza, due to both the strategic complexity and the enemy’s changing characteristics. In practice, rather than fighting regular armies in open battlefields, Israel was compelled to fight terror armies operating from densely populated areas and from the subterranean domain. All this was seemingly known in advance and should have required appropriate preparations and a prior reassessment of the security concept. To some extent, such a reassessment did occur and had implications for force building and employment, but these were not fully internalized across the board, particularly within the intelligence, planning, and operations bodies dealing with the Gaza Strip.
The conceptions that led up to the war, partly derived from the security concept, assumed that the defense establishment could provide timely warning on Gaza, that Israel deterred Hamas there, and that Israel could defend against any Hamas offensive and, if necessary, defeat it. They also included the assumption that because Hamas is a chronic threat with which one can live – “mowing the grass” whenever its jihadist nature sparked escalation -there was no need to act decisively to prevent its military build-up. In practice, all these assumptions proved baseless. Worse still, the clash with Hamas ignited many additional arenas at varying intensities, forcing Israel to cooperate with the United States to defend itself and take care of the Iranian threats with relative success.
Accordingly, Israel must update its security concept, including both the four pillars and the accompanying principles. First and foremost, Israel appears to need to add a new pillar: prevention and suppression of force build-up. Israel cannot allow the development of threats to its security near its borders or in the second and third rings (a nuclear program and missiles in Iran; missiles and UAVs in Yemen and Iraq). Implementing this pillar requires cooperation and strategic understanding with the United States to guarantee freedom of action and the practical use of air and intelligence superiority.
The campaign between wars (MABAM), through which Israel sought to limit Hizbullah’s build-up and, to a lesser extent, Hamas’s, proved insufficient. Far more resolute measures are needed to realize this new pillar. The conditions for ending the current conflict must create an operational space that allows this pillar to be applied in all arenas. In practice, it means maintaining buffer zones controlled by the IDF in Gaza (including along the border with Egypt, to prevent arms smuggling), in Lebanon, in Syria, and in certain areas of Judea and Samaria (especially in the refugee camps).
It is no longer possible to base emergency and wartime readiness on the assumption of timely warning. The place of warning and of intelligence in general must be redefined within the security concept. Intelligence plays a crucial role in each component of the concept, but the expectation that it will provide timely warning has proven unrealistic. This means the new pillar, preventing and suppressing force build-up, is essential to reduce the likelihood of surprise attacks. It also means that Israel needs a significantly larger army than the IDF on October 7 to deploy adequate forces across all plausible theaters, according to updated reference scenarios.
Deterrence must also be updated. Until October 7, the working assumption was that an enemy familiar with the IDF’s power would be deterred and prefer to avoid confrontation. The Hamas attack and ensuing war demonstrated that the willingness to sacrifice among radical Islamist actors, along with their assessment of Israel’s internal weaknesses, can motivate them to attack despite the IDF’s strength. Their calculations also included the costs of not acting, for example, in light of Israel–Saudi normalization.
Moreover, deterrence has proven to be a multidimensional and relative concept. An enemy may be deterred from a full-scale war with Israel, yet be less deterred by a controlled escalation focused mainly on exchanges of fire, especially if refraining would damage its standing and prestige among its target audiences. This describes Hizbullah’s conduct at least until July 2024 during the period of controlled escalation. Assessing an enemy’s level of deterrence is another elusive task for intelligence, one in which it also failed, and the security concept should not rely too heavily on success in this task. For this reason as well, the IDF’s order of battle must be expanded.
Defense also failed on October 7. It relied excessively on the barrier system, which collapsed in an instant, while the division had no preparation for such a case. Area defense and the defense of communities and permanent bases functioned only partially. As for air defense, performance against missiles was relatively good, but gaps were revealed in countering attacking UAVs.
The conclusion is that Israel must ensure defensible borders in all sectors, with the territorial implications that entail, and it must improve the overall defense concept and all its components. Some defensive lessons are already being implemented, including greater use of relatively older reservists for area defense. The need for defensible borders is also a clear American interest, not only because of the U.S. commitment to Israel’s security but also because, in their absence, extremists are more incentivized to attack Israel. Without defensible borders, Israel becomes more sensitive to potential threats, and as a result, the likelihood of regional instability that endangers Washington’s allies increases.
A decisive victory remains the most significant pillar. Israel’s defense establishment demonstrated its strength in this regard during the recent war, both against immediate enemies and distant ones. At the same time, the limits of power were exposed. The IDF did not bring down Hamas, not necessarily because of military incapacity, but apparently because of a considered decision that the strategic, military, moral, and economic costs would outweigh the benefits. Yet this assessment also stemmed from a lack of resolve to create a complete change in Gaza’s reality after October 7, particularly the removal of Hamas from its position of control. The required change, therefore, concerns both the scale and composition of forces, especially strengthening the ground army, as well as the command ethos.
Updating the security concept requires renewed understanding that Israel faces a significant and ongoing threat from its regional enemies and cannot afford complacency at any time. The concept must also reflect the need to operate across multiple arenas, including international legitimacy.
This brief volume presents reflections by several veterans of Israel’s security-concept design on the implications of the “Iron Swords” war for that concept. Some of the military implications have already been examined by the Nagel Committee, which called for a substantial increase in the defense budget and identified key directions needed in force building. However, the scope and direction of change remain open to debate, partly professional, partly political, and, in the end, it will be the democratic decisions of the public that are implemented.
