Beneath the Iron Dome, Iran tests Israel’s deterrence

The intensifying conflict between Iran and Israel has exposed both the strengths and vulnerabilities of Israel’s military posture, particularly its dependence on air defense systems to shield its territory from a sustained ballistic missile campaign. While Israel’s technologically advanced missile defence architecture has proven capable of intercepting the vast majority of Iranian missiles so far, it faces a reckoning now: Can Israel maintain its missile shield in a long-term war of attrition?

Since Iran initiated missile attacks last week, Israel’s multi-layered air defense system — a complex integration of Iron Dome (short-range), David’s Sling (medium-range), and the Arrow system (long-range) — has been operating at near-full capacity. The Arrow system, in particular, designed to intercept high-altitude ballistic missiles outside the atmosphere, has become the lynchpin of Israel’s strategic defense against Iran’s increasingly precise, long-range threats.

The performance of these systems has been stellar. According to various media reports quoting Israeli authorities, most of the incoming missiles have been successfully intercepted, preventing significant infrastructure damage or civilian casualties. However, success comes at a cost, and that cost is becoming a pressing concern in military and political circles in Israel.

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Unsustainable burn rate of interceptors
Reports from The New York Times and The Wall Street Journal indicate a growing concern among Israeli defence officials about the pace at which interceptors are being used. A senior US official confirmed that Israel’s supply of Arrow interceptors, costing roughly $3 million each, is running low. If Iran maintains its current tempo of missile launches, Israel may only have enough interceptors left for 10 to 12 more days, according to intelligence sources quoted by the WSJ. Moreover, Israeli financial daily The Marker estimates that nightly missile defense operations could cost as much as 1 billion shekels (approximately $285 million). This extraordinary financial burden is compounded by the logistical limits of replenishing high-tech interceptors that require months to manufacture and assemble.

In the context of attritional warfare, where endurance and resupply become as important as battlefield success, Israel’s heavy reliance on missile defence may become a strategic liability. Iran’s ballistic missile arsenal, one of the largest in the world, allows it to absorb higher losses and maintain pressure without necessarily achieving direct military victories. For Iran, the cost of launching a missile is significantly lower than the cost for Israel to intercept one. This imbalance introduces a dangerous asymmetry. Even if each Iranian missile is intercepted, the financial and logistical strain on Israel could grow unsustainable over time. Attrition, in this case, becomes a tool of strategic leverage for Iran, by forcing Israel into a prolonged and expensive defence.

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Strategic shift: From defence to offence?
Given this vulnerability, Israel’s ability to sustain its current operational tempo may hinge not only on its domestic industrial capacity but also on rapid US resupply. The US has historically supported Israel with missile defence funding and technological cooperation. US strategic planners are reportedly considering ways to boost production and provide emergency shipments, but even under optimal conditions, these efforts may not keep pace with operational demands if the war drags on for weeks or months. The chance of a missile shortage, especially for critical systems like Arrow, raises the possibility that Israel may have to prioritise targets, ration interceptors or rely more heavily on offensive operations to degrade Iran’s launch capabilities.Facing an attritional scenario, Israel may be compelled to shift its operational doctrine. Rather than absorb waves of missile attacks, Israeli forces could increase the scale and intensity of air strikes inside Iran in an attempt to preempt or degrade its missile capabilities at the source. This shift would, however, raise the stakes dramatically and could lead to a broader regional escalation involving Iranian proxies in Lebanon, Syria, Iraq and Yemen. This would also carry political and humanitarian costs, particularly if Iranian counterstrikes increase civilian casualties.

Israel’s air defense system has performed with impressive precision and effectiveness, maintaining the country’s security during the initial days of conflict. However, the sustainability of this defence is now in question. US President Donald Trump has given a two-week deadline for making a decision whether to enter conflict. With missile interceptor supplies dwindling and resupply timelines uncertain, Israel faces a narrowing window in which to recalibrate its strategy.

If the war continues at its current pace, Israel will soon be forced to decide between escalating offensively to reduce the missile threat or adjusting its defense doctrine to prioritize critical assets. Either choice will pose significant risks. Israel, a country renowned for its military innovation, may now face its most severe test — not in defeating its enemies outright, but in sustaining its defence long enough to shape the endgame.