Deterrence and the Lessons of the Iran War
Elli Lieberman’s work on deterrence provides a useful framework for assessing the strategic meaning of Israel’s war against Iran. In Reconceptualizing Deterrence, Lieberman moves beyond the traditional conception of deterrence as a relatively static relationship in which one state possesses sufficient military capability to threaten unacceptable costs and thereby prevent an adversary from taking a particular action. Deterrence is instead understood as a dynamic process that develops through repeated interaction between adversaries. Its effectiveness depends not simply on the ability to inflict costs, but on whether the adversary incorporates those expected costs into its strategic decision-making and comes to recognize that previously viable strategies for achieving victory are no longer realistic. The objective is consequently more than temporary behavioral restraint. Deterrence is most effective when the adversary comes to accept that pursuing a particular course of action is no longer worth the expected consequences.
This framework provides a useful way to assess Eado Hecht and Eitan Shamir’s Beyond Victory: How Should Israel’s War Against Iran Be Assessed? Hecht and Shamir argue that Israel’s war against Iran should not be judged simply by the amount of physical destruction inflicted on Iran. The destruction of nuclear facilities, missile systems, command centers, and proxy capabilities represents important operational and strategic achievements, but those achievements do not by themselves establish deterrence. Their broader argument is that Israel’s success should be measured by the extent to which it has disrupted Iran’s strategic architecture and delayed its ability to reconstruct the capabilities necessary to threaten Israel. This emphasis on the adversary’s broader strategy is consistent with Lieberman’s reconceptualization of deterrence. At the same time, Lieberman’s framework adds an important question: whether military degradation is ultimately translated into a change in the adversary’s strategic calculations.
The question becomes particularly important when considering the initial evidence concerning what Iran believes it learned from the war. In “How the Iran War Changed the Middle East,” Dr. Reza Parchizadeh emphasizes the psychological consequences of the conflict and argues that one of its most important effects was a transformation in strategic perceptions. His analysis suggests that Iran’s ability to survive extensive Israeli and American military operations may have reinforced the Iranian leadership’s belief that it can absorb considerable punishment while remaining politically intact and continuing to impose costs on its adversaries. From a deterrence perspective, this matters because perceptions are an essential component of the deterrence relationship. If Iran interprets its survival as evidence that it can withstand future confrontation, the psychological consequences of the war could weaken Israeli deterrence even in the face of overwhelming Israeli military superiority.
Parchizadeh’s argument, however, needs to be considered in relation to the specific objectives Israel sought to achieve. Iran’s survival cannot by itself demonstrate either deterrence success or failure. Had Israel’s objective been regime change, the continued survival of the Iranian regime would represent a strategic failure. If its objectives were instead to delay Iran’s nuclear program, degrade its missile forces, weaken its regional network, or alter particular aspects of Iranian behavior, the survival of the regime would not necessarily indicate that deterrence had failed. Deterrence must always be evaluated against the behavior it is intended to prevent. This point is important to Lieberman’s approach because it prevents very different outcomes—regime survival, military degradation, behavioral restraint, and strategic transformation—from being treated as interchangeable measures of success or failure.
Lieberman’s Deterring Terrorism extends this framework to asymmetric conflict and is particularly relevant to the question of Iranian resilience. Terrorist organizations and other weaker actors do not necessarily define victory in terms of battlefield superiority. Their strategies may instead depend on survival, endurance, regeneration, and the ability to impose sufficient costs on a stronger adversary to make continued confrontation politically unsustainable. A weaker actor can therefore turn its inability to defeat a stronger opponent militarily into a strategic asset by demonstrating that it can absorb punishment without abandoning its fundamental objectives. Resilience itself can become part of the strategy.
Although Iran is a state rather than a terrorist organization, this logic of asymmetric endurance has relevance to the conflict. Iran does not need to defeat Israel militarily in order to challenge Israeli deterrence. It can seek to demonstrate that Israel possesses extraordinary military capabilities but that those capabilities cannot compel Iran to abandon its fundamental strategic objectives. If Iran concludes that it can repeatedly absorb Israeli attacks, rebuild damaged capabilities, and continue imposing costs on Israel and its allies, endurance can become a form of strategic resistance. Israeli military superiority could then coexist with limited deterrence.
This possibility recalls Lieberman’s analysis of Israel’s relationship with Hamas before October 7. Israel repeatedly employed military force to punish Hamas and degrade its capabilities, and each round of fighting was followed by a period of relative calm. The resulting quiet could be interpreted as evidence that deterrence was functioning. October 7 demonstrated, however, that temporary behavioral restraint does not necessarily represent the internalization of deterrence. Hamas had used the periods between conflicts to preserve its organization, develop new capabilities, and prepare for a substantially more ambitious attack. The problem was that Israel misinterpreted the significance of the absence of attacks and treated tactical stability as evidence of strategic deterrence.
The October 7 experience offers an important warning in assessing the Iran war. Israel should be careful not to assume that extraordinary military destruction necessarily means that deterrence has been established. Before October 7, relative quiet could be interpreted as evidence that Israel’s strategy was working even while Hamas was preparing for a major attack. After the Iran war, Israel could make a similar error if it treats the destruction of Iranian capabilities as proof that Iran has been deterred while the Iranian leadership has instead concluded that it can survive and eventually reconstruct. In both cases, what happened on the battlefield is less revealing than what the adversary learned from the interaction.
Parchizadeh’s emphasis on psychological transformation is useful in this regard because it offers an initial indication of possible Iranian strategic learning. Iran may have learned that Israel and the United States possess the capability and willingness to inflict extraordinary damage. At the same time, it may have learned that Iran itself can survive such an assault. These conclusions are not necessarily contradictory. Recognition of overwhelming Israeli military power could make Iranian leaders more cautious, while confidence in Iran’s ability to absorb punishment could make them more willing to continue challenging Israel. The long-term effect will depend on which of these lessons becomes more influential in Iranian strategic decision-making.
Psychological resilience, however, has to be considered alongside the actual balance of capabilities. A state may emerge from a war believing that it has demonstrated resilience while possessing substantially fewer military options than it had before the conflict. This is where Hecht and Shamir’s emphasis on Iran’s strategic architecture becomes particularly important. Iran’s nuclear infrastructure, missile forces, command structures, and network of regional proxies provide the material basis for its strategy. If these capabilities have been degraded sufficiently to make reconstruction difficult, Iranian psychological confidence may have limited strategic significance. If Iran can rebuild them relatively quickly and restore its regional position, its perception that it successfully endured the war becomes much more consequential.
Deterrence by denial also matters in this context. Deterrence does not operate exclusively through threats of punishment; it can also operate by making the adversary’s objectives increasingly difficult or impossible to achieve. Israel’s ability to prevent Iran from rebuilding its nuclear and missile capabilities or restoring its regional proxy network could therefore contribute significantly to deterrence even if Iranian leaders remain psychologically confident. Iran’s belief that it survived the war does not necessarily mean that it can restore the strategic capabilities it possessed before the war. Psychological perceptions and material capabilities therefore have to be assessed together.
The distinction between capability, credibility, and resolve is equally important. Israel’s military performance demonstrates extraordinary capability, but capability alone does not establish credibility. Credibility depends on whether Iran believes that Israel will continue to employ that capability when necessary. Resolve is particularly important because deterrence may require the defender to sustain costs over an extended period. If Iran concludes that Israel possesses overwhelming military power but lacks the political willingness to sustain a prolonged campaign, Israeli deterrence could weaken despite Israel’s military superiority. If, on the other hand, Israel consistently demonstrates that it is prepared to impose substantial costs whenever Iran crosses clearly established red lines, Iranian confidence in its ability to endure punishment may become less useful as a basis for continued confrontation.
These factors make deterrence an inherently dynamic process. Neither Israel nor Iran enters each confrontation with fixed perceptions. Both learn from previous encounters, reassess the other’s capabilities and resolve, and modify their strategies accordingly. The Iran war should therefore be viewed not as the final determination of the deterrence relationship but as another stage in an ongoing process of strategic interaction. Its significance will become clearer as Iran decides whether and how to reconstruct its capabilities, alter its regional strategy, and respond to future Israeli actions.
Hecht and Shamir’s emphasis on time is particularly compatible with Lieberman’s theory. They suggest that Israel’s success should partly be measured by how long Iran is prevented from reconstructing its strategic capabilities. From Lieberman’s perspective, time has another significance: it provides an opportunity to determine whether military outcomes have been translated into durable changes in Iranian strategic behavior. A prolonged inability to reconstruct capabilities could strengthen deterrence by denial. A decision to abandon or substantially modify certain strategies could provide evidence of deterrence through changed preferences. Conversely, rapid reconstruction combined with renewed confrontation would suggest that Israel achieved significant military success without producing durable deterrence.
Taken together, Reconceptualizing Deterrence, Deterring Terrorism, the October 7 analysis, Hecht and Shamir’s assessment of the Iran war, and Parchizadeh’s discussion of its psychological consequences provide a useful framework for evaluating what the war may have accomplished. Reconceptualizing Deterrence establishes deterrence as a dynamic process involving capability, credibility, perception, resolve, and strategic learning. Deterring Terrorism demonstrates the particular difficulties that arise when weaker actors use endurance and attrition as strategic instruments. The October 7 experience illustrates the danger of confusing temporary restraint with genuine deterrence. Hecht and Shamir extend the problem to a state adversary by emphasizing the importance of disrupting the adversary’s broader strategic architecture. Parchizadeh adds a psychological dimension by suggesting that Iran may have interpreted its survival as evidence of strategic resilience.
The initial Iranian lesson from the war is therefore ambiguous. Iran may have learned that Israel possesses both the capability and willingness to inflict enormous damage. It may also have learned that it can survive such an assault. The first lesson could strengthen deterrence; the second could weaken it. Iran may emerge from the war psychologically more confident while being materially weaker, or materially constrained but more determined to rebuild. None of these possibilities can yet be equated automatically with deterrence success or failure.
The ultimate significance of the war will depend on the relationship between Iranian perceptions and Iranian behavior. If Iran concludes that rebuilding its previous strategic architecture would expose it to unacceptable costs and consequently modifies its behavior, the war may eventually prove to have strengthened Israeli deterrence. If Iran instead concludes that it can absorb the costs, reconstruct its capabilities, and resume the same strategic objectives, Israel may have achieved a substantial military victory without establishing durable deterrence. The critical distinctions are therefore between survival and strategic success, destruction and deterrence, and temporary restraint and internalized deterrence.
The lesson of October 7 remains central to this assessment. Israel’s earlier mistake was to interpret the absence of attacks as evidence that Hamas had been deterred. The danger after the Iran war is to interpret the destruction of Iranian capabilities as evidence that Iran has been deterred. Lieberman’s reconceptualization suggests a more demanding standard. Deterrence succeeds when the interaction of capability, credibility, resolve, denial, perception, and strategic learning produces a durable change in the adversary’s behavior.
The most important outcome of the Iran war therefore cannot yet be determined by counting destroyed targets or assessing which side claims victory. Its decisive consequences will emerge through the subsequent interaction between Israel and Iran. Parchizadeh is right to emphasize that the psychological consequences of the war may prove more important than some of its immediate military consequences, but those psychological consequences must ultimately be measured against Iranian behavior and capabilities. Hecht and Shamir are similarly right that strategic victory requires more than battlefield destruction, but their analysis needs the additional deterrence question supplied by Lieberman: whether the disruption of Iran’s strategic architecture changes Iranian calculations in a durable way. The war has created the conditions for a possible transformation of deterrence, but it has not yet demonstrated that such a transformation has occurred.
